COVID-19 Vaccine Frontrunners
Stay up-to-date on the progress of dozens of vaccine candidates that are currently undergoing clinical testing.
The Scientist Staff
Apr 7, 2020
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In early March 2020, National Institutes of Allergy and Infectious Diseases Director Anthony Fauci stated that it would take at least a year to a year and a half to get a COVID-19 vaccine approved for use in the US, and that estimate may be optimistic, according to some experts. There are many unknowns this early in the game. How the early candidates will perform, which will be advanced to later stages of clinical development, what safety issues might arise, and how a successful vaccine will be mass produced are among the questions that are now getting attention and funding.
See “Newer Vaccine Technologies Deployed to Develop COVID-19 Shot”
The Coalition for Epidemic Preparedness Innovations (CEPI), a nonprofit dedicated to the development of vaccines against emerging infectious diseases, was an early source of cash for this endeavor and has continued to pour money into vaccine development. Another early bolus of funds came from the Biomedical Advanced Research and Development Authority (BARDA), part of the HHS Office of the Assistant Secretary for Preparedness and Response, which contributed hundreds of millions of dollars to two top vaccine candidates: one made by Johnson & Johnson’s Janssen division and another developed by Moderna in collaboration with the US government. The US government’s Operation Warp Speed has also invested heavily, giving more than $1 billion each to Novavax and to AstraZeneca, which is collaborating on a vaccine developed by the University of Oxford, early on in the pandemic, and investing a total of more than $11 billion (including through BARDA) by the end of September, according to Genetic Engineering & Biotechnology News.
See “US Selects Two COVID-19 Vaccine Candidates for Huge Investments”
Below, The Scientist rounds up those vaccine candidates that appear to be furthest along. But there are many more in preclinical development. “Nobody knows which vaccines are going to work,” Moderna CEO Stéphane Bancel told Science in March.
See “Clinical Trial of COVID-19 Vaccine Begins in Seattle”
Editor’s note: The introduction of this story was updated on November 3 to reflect new developments in funding.
Table updated April 12, 2021. New material highlighted in red.
DEVELOPER(S) | VACCINE METHOD | EVIDENCE | STATUS |
| VACCINES THAT HAVE RECEIVED APPROVALS | |||
BioNTech and Pfizer International | Four RNA vaccine candidates are being tested in parallel. | Results from a Phase 3 trial published in December 2020 point to 95 percent fewer symptomatic COVID-19 cases among vaccinated individuals compared with placebo-injected controls. In vitro studies published in February 2021 found that the vaccine was effective against mutations in new variants including B.1.351, first detected in South Africa, and B.1.1.7, first spotted in the UK. Other findings that month from a nationwide vaccination program in Israel indicate that the vaccine was 46 percent effective at preventing disease 14 to 20 days after the first dose and 92 percent effective at 7 days after the second shot. In March 2021, the company announced results from its Phase 3 trial indicating that the vaccine is 100 percent effective in children aged 12–15. | Late stage trials are ongoing in the US, Germany, Brazil, South Africa, China, and other countries. In March 2021, the company announced that a Phase 1/2/3 trial is underway to test the vaccine in children aged 6 months to 11 years. On February 18, 2021, the company announced that a Phase 2/3 trial in pregnant women has commenced in the US. In December 2020, the UK, Bahrain, Canada, the US, Mexico, and the EU approved the vaccine for emergency use, while Saudi Arabia, Switzerland, and Brazil have given it full approval. Also in December, the World Health Organization granted the vaccine WHO’s first emergency use validation. In early 2021, Australia’s, Hong Kong’s, and Japan’s regulatory agencies also greenlighted the vaccine. On February 25, 2021, the company announced that participants from the Phase 1 trial will be offered a booster shot as part of study to determine the effectiveness of a third dose against virus variants. In addition, the company says it is working on developing a modified mRNA vaccine aimed at variants. |
Moderna and the US government US | Lipid nanoparticles containing mRNAs for the SARS-CoV-2 spike protein are injected into the arm. | Preliminary results from studies on older adults and those under age 55 suggest that the vaccine is safe and elicits higher levels of SARS-CoV-2 antibodies than does infection with the virus, and data from the Phase 3 trial suggest that it is nearly 95 percent protective, the company announced at the end of November. A third study finds that vaccinated monkeys quickly cleared the virus. Moderna is developing similar vaccines against Zika and other viruses, but to date, no vaccine of this type has been approved for use. | Phase 1, Phase 2, and Phase 3 clinical trials are underway across the US, and in December, 2020, the company announced that it would begin to test the vaccine on adolescents 12 years and older. In December, 2020, the FDA green-lighted the vaccine’s emergency use. Less than a week later, Canada’s regulatory agency did the same. In January, 2021, the EU, the UK, Israel, and Switzerland also followed suit. On February 24, 2021, the company announced it has commenced Phase 1 trials to test the effectiveness of three different types of booster shots against new virus variants. In March 2021, the company announced a Phase 2/3 trial is underway in the US and Canada to test the vaccine in children aged 6 months to 12 years. |
CanSino Biologics and the Academy of Military Medical Sciences China, Canada, Russia, and Saudi Arabia | Nonreplicating adenovirus 5 (Ad5) vector carrying the gene for the SARS-CoV-2 spike protein is injected into the arm. | Preliminary results from the Phase 2 trial published in The Lancet in July suggest that the vaccine is safe and elicits an immune response, either a T cell response or an antibody response. Adenoviruses are well-established vaccine vectors, and CanSino produced an Ebola vaccine (approved in China in 2017) using the same Ad5 platform. | Phase 1 and Phase 2 clinical trials are underway in Wuhan, China. A Phase 1/2 study is underway in Canada, while Phase 3 trials are ongoing in Saudi Arabia as well as in Mexico, Chile, Russia, Pakistan, and Argentina. In June 2020, following positive Phase 1 data published in The Lancet in May, China’s Central Military Commission approved the vaccine’s use by the country’s military for a year. In February 2021, the country approved it for widespread use, as did Mexico and Pakistan. In March 2021, Hungary approved the vaccine for emergency use. |
University of Oxford and AstraZeneca International | A chimpanzee adenovirus vaccine vector (ChAdOx1) carrying the gene for the SARS-CoV-2 spike protein is injected into the arm. | Preliminary results from the Phase 1/2 trial of people up to 55 years old published in The Lancet in July 2020 suggest that the vaccine is safe and elicits strong antibody and T cell immune responses, and preliminary results from a Phase 2 study published in The Lancet in November finds similar results for older individuals. Preliminary results from the Phase 3 study showed the vaccine to be 70 percent effective on average, according to results published in December in The Lancet, with one and a half doses being more effective than two doses. According to a study published in The Lancet in February 2021 summarizing data on subsets of participants, a single dose is 76 percent effective for up to three months post-vaccination, and a second dose given three months or more after the first dose boosts that efficacy to more than 82 percent. The vaccine appears to be far less effective against the B.1.351 variant circulating in South Africa, according to a yet-to-be-published analysis released on February 7, 2021. A Phase 1 trial using the same adenovirus vector to target MERS is ongoing in Saudi Arabia. | Clinical trials at various stages are underway around the globe, with expansion to more countries expected. Researchers in the UK will also test an inhaled form in an early-stage trial. In February 2021, the developers announced that they would begin a Phase 2 trial to test children as young as six years old. At the end of December 2020, the UK, Argentina, El Salvador, Kenya, and the Dominican Republic approved the vaccine’s emergency use. In January 2021, India’s, Mexico’s, Nepal’s, Morocco’s, Thailand’s, and the EU’s regulatory agencies did the same. South Africa had also greenlighted the vaccine but announced that it was halting its rollout after the results in early February suggested limited efficacy against the B.1.351 variant. In mid-February 2021, the World Health Organization granted the vaccine emergency use validation. In March 2021, Canada and Brazil approved the vaccine, Germany approved it for those over the age of 65, and Hungary approved CoviShield, the Indian version of the AstraZeneca shot, for emergency use. In early March 2021, the vaccine was suspended in several European countries due to concerns over blood clots, but resumed again after health authorities ruled the vaccine was safe. Later that month, Germany and Canada suspended the vaccine for use in people under age 60 and 55, respectively. |
Sinovac Biotech China, Brazil, Bangladesh, and Indonesia | Inactivated SARS-CoV-2 | Results from the Phase 1/2 trial published in The Lancet Infectious Diseases in November 2020 suggest that the vaccine is safe and elicits an antibody-based immune response, although antibody levels were lower than in patients who have been infected and recovered. In January 2021, officials in Brazil announced results suggesting that the vaccine is 78 percent effective, though updated findings released the following week pointed to an efficacy rate of closer to 50 percent, The New York Times reports. Phase 3 trials indicate that the vaccine is 83.5 percent effective at preventing disease, a revision from an earlier finding of 91.25 percent, Reuters reports. In March 2021, the company announced preliminary results that the vaccine is safe for children as young as three years old, according to the AP. Sinovac had used a similar platform to develop a vaccine against SARS in 2004 that showed promising results in early-stage human trials. | A Phase 1/2 clinical trial is underway in China, and Phase 3 trials are ongoing in Bangladesh, Indonesia, and Turkey. A trial is also underway in Brazil. China approved the vaccine’s emergency use for high-risk individuals in July, and for widespread application in February, following regulatory greenlights in Indonesia and Turkey. As of March, the vaccine has received emergency use authorization in at least a dozen countries. |
Wuhan Institute of Biological Products and China National Pharmaceutical Group (Sinopharm) China and United Arab Emirates (UAE) | Inactivated SARS-CoV-2 | In mid-June, Sinopharm announced that nearly all of the more than 1,000 participants who had received two injections of the mid-dose vaccine tested positive for antibodies against SARS-CoV-2. In August, Phase 1/2 trial results published in JAMA indicated that the vaccine is safe and elicited neutralizing antibodies. In December, the UAE’s Ministry of Health and Prevention announced that an interim analysis the ongoing Phase 3 trial suggests that the vaccine is 86 percent effective. | A Phase 1/2 clinical trial is underway in China. A Phase 3 trial is underway in UAE, and another is underway in Peru. In December, the UAE approved the vaccine for emergency use, and China approved the vaccine’s widespread use in February. |
Beijing Institute of Biological Products and China National Pharmaceutical Group (Sinopharm) China | Inactivated SARS-CoV-2 | The two-dose vaccine protects rhesus macaques against SARS-CoV-2, according to a paper published in Cell in early June. In mid-October, Sinopharm published results from the early trials in The Lancet showing that the vaccine was safe and that participants receiving the vaccine had high titers of antibodies. | A Phase 1/2 clinical trial is underway in China, which granted the vaccine full approval at the end of December, as did UAE and Bahrain. Phase 3 trials are proceeding in Peru, Morocco, UAE, Egypt, and other countries, and Egypt and Jordan have so far granted approval for emergency use. |
Gamaleya Research Institute of Epidemiology and Microbiology, Health Ministry of the Russian Federation, Acellena Contract Drug Research and Development Russia and United Arab Emirates (UAE) | Adenovirus vector displaying the SARS-CoV-2 spike protein on its surface | Preliminary results from the early stage trial published in September in The Lancet point to the Sputnik V vaccine candidate’s safety and ability to elicit an antibody response. In January, also in The Lancet, Gamaleya published preliminary results from the ongoing Phase 3 trial that suggest the vaccine is more than 90 percent effective—a statistic that attracted criticism after it was first announced in November. | Phase 1/2 clinical trials are underway in Russia to test liquid and powder forms of the vaccine, while additional trials are being conducted in Belarus, Venezuela, UAE, and India. In August, Russian President Vladimir Putin said that the country approved the vaccine ahead of a Phase 3 trial. Since late December, the Russian Direct Investment Fund has stated that more than four dozen other countries have also okayed its use. |
Bharat Biotech India | Inactivated SARS-CoV-2 | Results from a Phase 1 trial indicated that two intramuscular injections of the vaccine, known as BBV152, was well tolerated and elicited no serious adverse side effects. Interim results from a Phase 2 trial also found that the vaccine was safe and induced good antibody and T cell levels. Additional studies are needed to evaluate immune responses in children and people over 65 years old. | Phase 1/2 and Phase 3 trials are underway in India. The country’s regulatory agency approved the vaccine for emergency use at the beginning of January, The New York Times reports. |
State Research Center of Virology and Biotechnology “Vector” Russia | Peptide-based vaccine based on a platform developed for an Ebola vaccine candidate | Volunteers in the Phase 2 trial are “feeling good,” the Russian consumer safety watchdog Rospotrebnadzor said in a statement, according to Reuters. | Clinical testing was completed by the end of September, according to Reuters. In October, Russian President Vladimir Putin announced its approval ahead of a Phase 3 trial, NPR reports, and on November 30, Reuters reported that the country will begin mass vaccinations. |
Chumakov Center at the Russian Academy of Sciences Russia | Inactivated SARS-CoV-2 | According to Reuters, no adverse effects of the vaccine, known as CoviVac, were observed in participants of an early-phase trial. | Phase 1/2 trials in three Russian cities were expected to be completed in November. According to Reuters, Russia approved the vaccine in February. |
Johnson & Johnson’s Janssen division International | Nonreplicating adenovirus 26 (Ad26) vector carrying undisclosed genetic material of SARS-CoV-2 is delivered via intramuscular injection. | In late September 2020, the company posted a preprint with preliminary results from an early-stage trial that showed a single dose of the vaccine to be safe and to elicit neutralizing antibodies in nearly all study participants. In January 2021, the company announced results from its Phase 3 study showing that the vaccine is 66 percent effective overall, including participants in the US, Latin America, and South Africa (where the B.1.351 variant is widely circulating). The company is also developing other Ad26-based vaccine candidates, including its Ebola vaccine that was deployed in Democratic Republic of Congo in November 2019. | Early stage clinical trials are underway in the US, Belgium, and Japan, and a Phase 2 trial is ongoing in Spain, Germany, and the Netherlands. Meanwhile, an international Phase 3 trial is underway in the US, Mexico, several South American countries, the Philippines, South Africa, and Ukraine. In mid-November, the company announced a second global Phase 3 trial that would test two doses of the vaccine instead of one. Bahrain, Canada, the US, the European Union, and Thailand have approved the vaccine for emergency use. In March 2021, the European Medicines Agency and the World Health Organization also granted the vaccine emergency use approval. |
| ADDITIONAL VACCINES IN CLINICAL TRIALS | |||
Walter Reed Army Institute of Research US | Nanoparticles studded with the SARS-CoV-2 spike protein created using ferritin, an iron storage protein that self-assembles into spheres | Walter Reed’s two-dose vaccine candidate, SpFN, induced a potent and broadly neutralizing antibody response against the initial strain of SARS-CoV-2, two emergent variants, and SARS-CoV-1 in monkeys. | A Phase 1 clinical trial was launched in April 2021. |
OSE Immunotherapeutics Belgium | A vaccine designed using SARS-CoV-2 epitopes, small fragments of proteins that are recognized by the immune system’s T cells. | CoVepiT is a “multi-target multi-variant” vaccine that activates T cell defenses by targeting 11 different SARS-CoV-2 proteins. These proteins were chosen based on their low rate of mutation, making them less likely to spawn new variants. Positive preclinical results were reported in August 2020, with the candidate vaccine eliciting T cell responses with long-term protective immunity in the respiratory tract and lung of humanized mice and human cells. | OSE received approval on April 1 to launch a Phase 1 trial in Belgium. |
KM Biologics Japan | Inactivated SARS-CoV-2 | A Phase 1/2 clinical trial is currently underway. | |
Inovio Pharmaceuticals US and South Korea | A special device administers spike protein–encoding DNA molecules through the skin. | Mice and guinea pigs mounted immune responses against the virus, according to a recent preprint, and the company announced interim results from the Phase 1 trial at the end of June that suggested the vaccine was safe and spurred immune responses in 94 percent of the 36 participants analyzed. | Phase 1 and Phase 2/3 clinical trials are ongoing in the US. A Phase 1/2 study is also underway in South Korea. The Phase 3 trial of this vaccine is on hold while the FDA seeks more information about the device used to administer the injection, Reuters reports. |
Shenzhen Geno-Immune Medical Institute China | Immune cells (human dendritic cells and T cells, or artificial antigen presenting cells) are engineered to express a synthetic minigene based on SARS-CoV-2 proteins and injected or infused into the patient. | The research institute modifies cells using lentivirus vectors that it has used to develop CAR T cell therapies as well as gene therapies. | A Phase 1/2 clinical trial is underway in China for the dendritic cell and T cell–based vaccines, and a Phase 1 trial is underway for a vaccine using artificial antigen presenting cells. |
Clover Bio-pharmaceuticals International | The vaccine delivers pieces of the SARS-CoV-2 spike protein. | The company announced in December that the vaccine candidate, in combination with adjuvants, was safe and induced neutralizing antibodies and cell-mediated immunity—results that were also posted as a preprint. The Trimer-Tag platform used is the basis for other viral vaccines in development. | Phase 1 and Phase 2/3 trials are underway in Australia, Belgium, Germany, Nepal, the Philippines, Poland, South Africa, Brazil, Colombia, the Dominican Republic, and Panama. |
Novavax Australia and South Africa | Nanoparticles carrying antigens derived from the SARS-CoV-2 spike protein (with Matrix-M adjuvant) | In 2012, the company started development on a SARS vaccine that served as the basis for its new SARS-CoV-2 vaccine candidate. Data from the Phase 1/2 trial published in The New England Journal of Medicine in early September 2020 show the vaccine candidate, known as NVX-CoV2373, to be safe and elicit neutralizing antibody levels greater than those provided by treatment with COVID-19 convalescent serum. In March 2021, the company announced results from Phase 3 trials in the UK and South Africa. UK results indicate that the vaccine is more than 96 percent effective at preventing mild and severe disease against earlier strains of the virus, but it is about 86.3 percent effective against preventing disease from the highly transmissible B.1.1.7 variant. The South African trial found that it was only about 46.3 percent effective at preventing disease from the B.1.351 variant. In both countries, it was 100 percent effective at preventing severe disease. | A Phase 1 clinical trial is underway in Australia, and a Phase 2 trial is underway in South Africa. Phase 3 trials are underway in the UK, the US, and India. |
CureVac Belgium and Germany | RNA vaccine; details not disclosed | In November, the company announced preliminary data from the ongoing Phase 1 trial that showed the vaccine candidate elicits levels of neutralizing antibodies comparable to levels seen in people who have recovered from serious COVID-19 illness and also appears to trigger the production of SARS-CoV-2–fighting T cells, Reuters reports. | Phase 1 and Phase 2/3 trials are underway in Belgium, Germany, and the Netherlands. A Phase 2 trial is also underway in Panama and Peru. |
Medicago US and Canada | Virus-like particles that resemble SARS-CoV-2 are produced in a close relative of tobacco. | The company has a rotavirus vaccine in clinical trials that is based on virus-like particles, and another for norovirus in preclinical studies. | Phase 1 and Phase 2/3 trials are underway in the US and Canada. In March 2021, a Phase 3 trial began in the US and Canada. |
Altimmune | An adenovirus-vector vaccine encoding the receptor binding domain (RBD) of the SARS-CoV-2 spike protein is delivered intranasally. | A preprint published in October suggests the vaccine elicits immune responses against the RBD in mice. The company is using the same technology to develop a flu vaccine that is in clinical trials. | A Phase 1 trial is underway |
AnGes, Japan Agency for Medical Research and Development Japan | Engineered circular DNA encoding the SARS-CoV-2 spike protein | The vaccine consists of two intramuscular injections. | |
Aivita Biomedical US | A patient’s own dendritic cells are modified to carry SARS-CoV-2 antigens and then reinfused. | Antigen-carrying dendritic cells triggered a response in the same patient’s lymphocytes in vitro. | A Phase 1/2 trial has been approved to begin in California. |
Genexine South Korea | DNA encoding the SARS-CoV-2 spike protein | The vaccine was shown to produce neutralizing antibodies in nonhuman primates. | Phase 1/2 trial underway in South Korea |
Vaxine, Medytox Australia | Recombinant SARS-CoV-2 spike protein plus a polysaccharide adjuvant | Vaxine developed an experimental swine flu vaccine during the 2009 pandemic. | Phase 1 trial approved to begin in Australia |
Zydus Cadila India | Engineered DNA plasmid encoding a SARS-CoV-2 antigen | In a preclinical study, the vaccine neutralized SARS-CoV-2 in a virus neutralization assay. | A Phase 1/2 trial is underway in India, and a Phase 3 trial is approved to proceed. |
Arcturus Therapeutics Singapore | Self-replicating mRNA encoding coronavirus proteins | The self-replicating mRNA platform is not the basis of any approved medicines, but preclinical results announced in April suggest the vaccine candidate triggers an immune response. | Phase 1/2 trial underway in Singapore |
Sanofi and GlaxoSmithKline (GSK) US | Antigen based on SARS-CoV-2 spike protein (with adjuvant) | Sanofi uses the same recombinant DNA technology in a flu vaccine and in a SARS vaccine candidate that never entered clinical trials. Meanwhile, GSK’s adjuvant, AS03, was used in vaccines the company made against the H1N1 and H5N1 pandemic flu viruses. | A Phase 1/2 trial is underway in the US, but after interim results from the study suggested that older participants mounted only weak immune responses, the companies announced a delay in the vaccine’s development timeline, aiming for regulatory submission in the second half of 2021. In February, the companies announced they were starting a new Phase 2 trial, including in older adults. The companies also said they would aim to target new virus variants. |
ImmunityBio US and South Africa | A human adenovirus (hAd5) vector delivers SARS-CoV-2 antigens, both the spike protein and the nucleocapsid protein found inside the virus. | The company says it is developing forms of the vaccine for subcutaneous, oral, inhaled, and intranasal administration. Preliminary results from a Phase 1 trial testing the subcutaneous version found a low dose to be safe, the company announced in November. A month later, a macaque study posted as a preprint showed that a combination of the subcutaneous and oral formulations to be safe and protective against a SARS-CoV-2 challenge. | A Phase 1 trial is underway in the US, and another Phase 1 trial is set to begin in South Africa. |
Institute of Microbiology at the Chinese Academy of Sciences and Anhui Zhifei Longcom Biologic Pharmacy Co. China | Recombinant protein vaccine based on the receptor-binding domain of SARS-CoV-2 spike protein | The ZF2001 vaccine is administered as three doses spaced 30 days apart. According to a non–peer-reviewed results in medRxiv, the Phase 1 and 2 trials indicated that the vaccine is safe and elicited immune responses. | Multiple Phase 1 trials, plus Phase 2 and Phase 3 trials, are ongoing in China. In March 2021, China and Uzbekistan approved the vaccine. |
West China Hospital of Sichuan University China | A portion of recombinant SARS-CoV-2 spike protein | The vaccine candidate was safe and effective in preventing infection with the novel coronavirus in animals including monkeys. The approach has been used to develop other vaccines, such as those against flu and cervical cancer. | A Phase 2 trial is set to begin in China, Reuters reported in mid-November. |
Symvivo Canada | Orally administered Bifidobacterium probiotic engineered to carry DNA encoding the SARS-CoV-2 spike protein | In addition to this vaccine currently in human testing, two other candidates for COVID-19 are being developed by Symvivo. | Phase 1 clinical trial underway in British Columbia and Nova Scotia |
Kentucky BioProcessing (a biotech owned by British American Tobacco) US | SARS-CoV-2 antigens produced by tobacco plants are injected into patients. | Kentucky BioProcessing claims its vaccine candidate has a production time of just six weeks and can be stored at room temperature. The company is conducting a Phase 1 clinical trial for an influenza vaccine candidate that uses the same plant-based technology. | A Phase 1 trial is approved to begin in the US. |
Valneva UK | Inactivated SARS-CoV-2 particles with high density of spike protein, in combination with two adjuvants | The vaccine candidate relies on the same technology that the company used to develop its approved Japanese encephalitis vaccine. | Phase 1/2 clinical trial underway in the UK |
Israel Institute for Biological Research Israel | Vesicular stomatitis viruses engineered to carry the SARS-CoV-2 spike protein | Preclinical studies in various animal models showed the vaccine to be safe and to bind to and neutralize SARS-CoV-2. Vesicular stomatitis viruses also form the basis of a newly approved vaccine for Ebola. | A Phase 1/2 trial is underway in Israel. |
Vaccine and Infectious Disease Organization at the University of Saskatchewan Canada | A portion of the SARS-CoV-2 spike protein | Protein subunit technology has been used in commercially available vaccines for hepatitis, whooping cough, and more. | A Phase 1/2 trial is approved to begin in Nova Scotia, Canada. |
Medigen Taiwan and Vietnam | A combination of SARS-CoV-2 spike proteins and an adjuvant | Preclinical studies suggest the vaccine candidate is safe and elicits an immune response. | Phase 1 and Phase 2 trials are underway in Taiwan and Vietnam. |
United Biomedical and COVAXX Taiwan | Peptide-based vaccine consisting of a SARS-CoV-2 spike protein subunit genetically fused to a single-chain Fc domain of human IgG1, combined with other proprietary peptides | According to a press release, results from the Phase 1 trial indicate that the UB-612 vaccine is safe and elicits high antibody titers. | |
Gritstone Oncology US | Two vaccine technologies combined: first, an adenovirus vector carrying the genes for the SARS-CoV-2 spike protein and other antigens; then, an mRNAs coding for the viral antigens | No preclinical data available, according to STAT. | A Phase 1 trial to will be conducted by the National Institute for of Allergy and Infectious Diseases. |
Immunitor Canada and Mongolia | Heat-inactivated plasma from donors with COVID-19 taken as a pill daily for a month | The initial safety test will give volunteers the pill for 15 days. | Phase 1/2 clinical trial underway in British Columbia and Mongolia |
Vaxart US | A pill containing different SARS-CoV-2 antigens | After testing five different vaccine candidates in animals, the company chose its lead candidate, which generated immune responses after a single dose, for clinical testing. The company has other oral recombinant vaccine candidates that have shown success in clinical trials. | Phase 1 trial underway in California |
ReiThera Italy | Proprietary replication-defective gorilla adenoviral (GRAd) vector encodes the SARS-CoV-2 spike protein. | In November 2020, the company announced that the GRAd-COV2 vaccine was well tolerated and induced immune responses in subjects aged 18–55 years. | |
Institute of Medical Biology at Chinese Academy of Medical Sciences, West China Second University Hospital, Yunnan Center for Disease Control and Prevention China | Inactivated SARS-CoV-2 | Data from the Phase 1 trial, posted as a preprint on October 6, suggests that the vaccine is safe and elicits an immune response, although levels of neutralizing antibody started to drop after just two weeks. | A Phase 1/2 clinical trial is underway in China, and a Phase 3 is ongoing in Brazil and Malaysia. |
University of Hong Kong and Xiamen University China and Hong Kong | A nasal-spray consisting of a genetically weakened form of the influenza virus that has been engineered to produce part of the SARS-CoV-2 spike protein | Preclinical work in mice and hamsters showed reduced lung damage upon infection with SARS-CoV-2 when animals were vaccinated. The vaccine’s developers hope that it will protect against flu at the same time. | A Phase 1 clinical trial is underway in China, and a second early-stage clinical trial is approved to begin in Hong Kong. |
German Center for Infection Research Germany | A harmless vector called modified vaccinia ankara (MVA) carries the gene for the SARS-CoV-2 spike protein. | The center previously used this approach to develop a vaccine against MERS. | A Phase 1 clinical trial is underway in Germany. In January, however, the center announced it was postponing a Phase 2 study due to limited immune responses in Phase 1 participants. |
City of Hope US | A synthetic modified vaccinia ankara (sMVA) encoding the SARS-CoV-2 spike and nucleocapsid proteins | Mice that received the vaccine generated high levels of neutralizing antibodies and strong T cell responses against the coronavirus’ spike and nucleocapsid antigens, according to research published in Nature Communications in November. | Phase 1 clinical trial underway in California |
Cellid South Korea | Adenovirus vector encoding the SARS-CoV-2 spike | Monkeys vaccinated had no detectable SARS-CoV-2 in the upper respiratory and lung tissue after being challenged with the virus. | Phase 1/2 clinical trial underway in South Korea |
SpyBiotech and Serum Institute of India Australia | Proprietary “superglue” technology is used to display the SARS-CoV-2 spike protein on the surface of hepatitis B surface antigen virus-like particles (VLPs) | Hepatitis B VLPs are globally licensed as a vaccine for hepatitis B virus. | Phase 1/2 clinical trial underway in Australia |
Biological E. Limited India | Protein subunit vaccine using receptor binding domain of the SARS-CoV-2 spike protein with adjuvant | The vaccine candidate is thermostable, which should make it possible to distribute in low-resource settings. | Phase 1/2 clinical trial underway in India |
Shionogi Japan | Recombinant protein vaccine | Preclinical studies yielded positive efficacy and safety results, the company announced, noting that the vaccine is stable in refrigerated conditions. | Phase 1/2 clinical trial underway in Japan |
University of Tübingen Germany | Multiple SARS-CoV-2 peptides with adjuvant | Unlike most other COVID-19 vaccine candidates, this one aims to specifically induce a T cell–mediated immune response. | Phase 1 clinical trial underway in Germany |
SK Bioscience and the University of Washington School of Medicine and GSK South Korea | Recombinant protein vaccine consisting of nanoparticles displaying the receptor binding domain of the SARS-CoV-2 spike protein with an adjuvant of aluminum hydroxide | A preclinical study indicated that the vaccine, known as GBP510, elicited high titers of neutralizing antibodies in mice. | A Phase 1/2 trial is underway in Korea. |
Nanogen Biopharmaceutical Vietnam | Protein subunit vaccine with adjuvant | Preclinical trials showed high safety and efficacy, according to the company’s website. Results from clinical trials are expected in the middle of 2021. | Phase 1/2 clinical trial underway in Vietnam |
Research Institute for Biological Safety Problems Kazakhstan | Inactivated SARS-CoV-2 | According to a government website, preliminary results from Phase 1 and 2 trials of the QazCovid-in vaccine indicate it is 96 percent effective. | |
Erciyes University Turkey | Inactivated SARS-CoV-2 | No serious side effects from Phase 1 trials were reported. | |
Codagenix and Serum Institute of India (SII) UK | Single-dose, intranasal, live-attenuated virus | Preliminary results from the Phase 1 trial of COVI-VAC are expected in mid-2021. | Phase 1 clinical trial underway in the UK |
Shafa Pharmed Pars Iran | The 30 participants experienced no side effects from the first dose of the vaccine, called COVIran Barekat, in the Phase 1 trial. | Phase 1 clinical trial underway in Iran | |
SK Bioscience Korea | SARS-CoV-2 recombinant protein subunit vaccine | According to Korea Biomedical Review, preclinical trials of the vaccine, known as NBP2001, indicated it was safe and elicited strong immune responses in primates. | A Phase 1 trial is underway in Korea |
VBI Vaccines Canada | A virus-like particle producing the SARS-CoV-2 spike protein | The company reported that the VBI-2902 vaccine elicited high neutralizing antibody titers in hamsters. Vaccinated animals exposed to the virus also had lower virus replication and reduced lung inflammation. | |
Icahn School of Medicine at Mount Sinai Thailand | A vector using Newcastle disease virus, an avian pathogen that causes little to no symptoms in humans, produces the spike protein of SARS-CoV-2 | According to a study published in EBioMedicine, intramuscular injection of the vaccine elicited high levels of antibodies in mice and protected them from infection when exposed to mouse-adapted SARS-CoV-2. | A Phase 1 trial is underway in Thailand. |
Takis and Rottapharm Biotech Italy | A DNA plasmid encoding the SARS-CoV-2 spike protein. Delivery of the DNA to cells is enhanced with electroporation, a technique that uses light and electrical stimulation to increase cell membrane permeability | According to the company, preclinical trials showed that the COVID-eVax vaccine is safe and elicits immune responses in animals | A Phase 1/2 trial is underway in Italy. |
Razi Vaccine & Serum Research Institute Iran | Recombinant protein subunit vaccine | Researchers are testing the delivery of the Razi Cov Pars vaccine via intramuscular injection and nasal spray. | A Phase 1 trial is underway in Iran. |
BioNet-Asia and Technovalia Asia and Australia | A DNA fragment encoding the SARS-CoV-2 spike protein is delivered to the skin or muscle without a needle. | According to the company, preclinical trials indicate that the vaccine, known as COVIGEN, is safe and elicits immune responses in animals. | A Phase 1 trial is underway in Australia. |
Meissa Vaccines US | A live, attenuated respiratory syncytial virus (RSV) expresses the gene for the spike protein of SARS-CoV-2. The vaccine is administered as drops or a nasal spray. | According to the company, preclinical trials showed that the MV-014 vaccine induced neutralizing antibodies in nonhuman primates and protected the animals from disease after exposure to the virus. | A Phase 1 trial is underway in the US |
Iran Ministry of Defense Iran | Inactivated SARS-CoV-2 | The vaccine is called FAKHRAVAC. | A Phase 1 trial is underway in Iran. |
Center for Genetic Engineering and Biotechnology of Cuba Cuba | Recombinant receptor-binding domain of SARS-CoV-2 spike protein with aluminum hydroxide adjuvant | According to a report, Phase 1 trials found that the vaccine, known as Abdala (CIGB 66), is safe and elicits immune responses. | |
Center for Genetic Engineering and Biotechnology of Cuba Cuba | The vaccine uses the SARS-CoV-2 spike protein along with a protein from the Hepatitis B virus (AgnHB). | According to a Cuban news site, Phase 1 trials of the vaccine, known as Mambisa (CIGB 669), which is delivered as a nasal spray, is safe and elicits immune responses. | A Phase 1 trial is underway in Cuba. |
Finlay Vaccine Institute Cuba | A conjugate vaccine composed of the receptor-binding domain of the SARS-CoV-2 spike protein connected chemically to a modified tetanus protein | The vaccine is known as Soberana-02 or FINLAY-FR-2. | A Phase 3 trial is underway Cuba. |
Finlay Vaccine Institute Cuba | Recombinant receptor-binding domain of SARS-CoV-2 spike protein | The vaccine is called Soberana-01. | Phase 1/2 trials are underway in Cuba. |
Sanofi and Translate Bio US | mRNA vaccine carrying the genetic sequence for the SARS-CoV-2 spike protein | Results from preclinical trials showed that the vaccine, known as MRT5500, was safe and elicited high antibody levels in mice and monkeys. | |
Daiichi Sankyo and University of Tokyo Japan | mRNA vaccine | According to an announcement from the company, preclinical studies found that the vaccine, known as DS-5670, was safe and effective. | In March 2021, the company announced that a Phase 1/2 trial is underway in Japan. |
Zhongyianke Biotech, Liaoning Maokangyuan Biotech, and the Academy of Military Medical Sciences China | Recombinant SARS-CoV-2 vaccine made within Chinese hamster ovary cells | In November 2020, a Phase 1 trial commenced. In March 2021, a Phase 2 trial began. | |
| VACCINES THAT HAVE BEEN ABANDONED | |||
Merck | A vesicular stomatitis virus (VSV) carries undisclosed viral components | The VSV vector is used for Merck’s existing Ebola vaccine. | The company announced in January that it was discontinuing development of the vaccine candidate due to insufficient immune responses in Phase 1 trial participants. |
Merck | A weakened measles virus vector carries undisclosed viral components | Merck is purchasing Vienna-based Themis, which has an existing measles vaccine, to develop the COVID-19 vaccine. | The company announced in January that it was discontinuing development of the vaccine candidate due to insufficient immune responses in Phase 1 trial participants. |
University of Queensland and CSL Australia | Molecular clamp technology presents viral proteins to the immune system. | Preclinical work in cell culture showed that the vaccine candidate elicited an immune response that was capable of neutralizing SARS-CoV-2 infection. | Results of a Phase 1 trial in Australia suggested the vaccine was safe and effective, but because it uses fragments from an HIV protein, some trial participants got false positives on HIV test, so CSL announced in December that it was canceling the project. |
Imperial College London | Self-amplifying RNA molecules are injected into the muscle. | The vaccine platform, which is designed to allow researchers to respond quickly to emerging pathogens, received $8.4 million from CEPI last December. “We cannot predict where or when Disease X will strike, but by developing these kinds of innovative vaccine technologies we can be ready for it,” CEPI CEO Richard Hatchett said at the time. | A Phase 1 trial is underway in the UK, but instead of advancing this vaccine candidate to efficacy trials in the UK, the university announced in January that it would focus its efforts on developing booster shots and vaccines that target emerging variants of the virus. |
In addition to vaccine candidates specific to SARS-CoV-2, several trials are underway testing vaccines against different pathogens as well as nonspecific formulations designed to stimulate an innate immune response.
DEVELOPER(S) | VACCINE METHOD | EVIDENCE | STATUS |
Multiple organizations International | The Bacille Calmette-Guerin (BCG) vaccine for tuberculosis consists of live attenuated Mycobacterium bovis. | Lower rates of COVID-19–related deaths in countries with mandatory BCG vaccination prompted the launch of several clinical trials to test whether the immune response triggered by the vaccine may protect against SARS-CoV-2. | Several Phase 3 and 4 trials are underway. |
Multiple organizations International | The measles-mumps-rubella (MMR) vaccine consists of live-attenuated strains of the three viruses. | Epidemiological data have revealed that places where the MMR vaccine is given as standard medical care have lower COVID-19 death rates than areas where MMR vaccination is not standard. Additionally, sailors aboard the U | A Phase 3 trial is underway in Egypt, led by researchers at Kasr El Aini Hospital. Separately, researchers at the Washington University School of Medicine are running an international Phase 3 trial of healthcare workers in the US, Canada, Europe, and Africa. |
Immunovative Therapies, Mirror Biologics US | An off-the-shelf living immune cell | The affiliated companies are currently testing the formulation as a therapeutic vaccine for chemotherapy-refractory metastatic cancers. | A Phase 1/2 trial for healthy older adults has been approved to begin in New York. |
Canadian Cancer Trials Group, others Canada | Heat-killed Mycobacterium obuense | The vaccine is intended to stimulate nonspecific innate immunity. The company is also testing the vaccine in clinical trials for cancer. | |
Bandim Health Project Guinea-Bissau | Oral polio vaccine, an attenuated strain of the poliovirus | Researchers argue that the vaccine is safer and available in greater quantities than the BCG vaccine against tuberculosis, which is also being tested as a possible COVID-19 preventive. | A Phase 4 trial has been approved to begin in Guinea-Bissau in West Africa. |
Inmunotek, BioClever Mexico | A mixture of inactivated bacteria | The vaccine is intended to stimulate nonspecific innate immunity. | A Phase 3 trial for healthcare workers has been approved to begin in Mexico. |
Pulmotect US | An inhaled combination of two synthetic Toll-like receptor agonists | The vaccine was originally developed as a potential therapeutic for cancer and has undergone early stage clinical testing. In mice, it provided protection against a range of respiratory pathogens, including MERS and SARS. | A Phase 2 trial for people with known SARS-CoV-2 exposure is underway in several US states. |
Corrections: An earlier versions of this table stated that Janssen’s adenovirus-based COVID-19 vaccine candidate is administered intranasally. In fact, the vaccine is administered via intramuscular injection. / An earlier version of this table stated that the Phase 1 and Phase 2 Moderna trials were taking place in Seattle. In fact, there have been multiple locations since the Phase 1. / A previous update to this table implied that the adverse event that caused the Phase 3 AstraZeneca trial to be put on hold occurred in the Phase 1/2 trial in the UK. In fact, the event occurred in a participant enrolled in the Phase 3 UK study. / A previous update to this table listed Switzerland as having given emergency use approval for the Pfizer/BioNTech COVID-19 vaccine. In fact, the country granted its full approval. / A previous version of this table indicated that UAE and Bahrain had given emergency approval for the Beijing Institute of Biological Products’s COVID-19 vaccine; in fact, these countries have granted full approval. / A previous version of this table stated that Altimmune’s vaccine was approved for a Phase 2 trial; in fact, it is approved for Phase 1. / A previous version of this table stated that China had approved the Sinopharm vaccine developed by Wuhan Institute of Biological Products in December 2020; in fact, that approval happened in February 2021. The Scientist regrets the errors.
