Updated Feb 24
COVID-19 Vaccine Frontrunners
Updated Feb 24
COVID-19 Vaccine Frontrunners

COVID-19 Vaccine Frontrunners

Stay up-to-date on the progress of dozens of vaccine candidates that are currently undergoing clinical testing.

Jef Akst
Jef Akst
Apr 7, 2020

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In early March, 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. 

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 The New England Journal of Medicine in December point to 95 percent fewer symptomatic COVID-19 cases among vaccinated individuals compared with placebo-injected controls. Studies published in Nature Medicine and The New England Journal of Medicine in February found that the vaccine was effective against mutations in new variants including B.1.351, the variant first detected in South Africa, and B.1.1.7, first spotted in the UK.

Late stage trials are ongoing in the US, Germany, Brazil, South Africa, China, and other countries; in October, the companies announced that the Phase 3 trial would expand to include adolescents 12 years and older. On February 18, the company announced that a Phase 2/3 trial in pregnant women has commenced in the US. In December, the UK, Bahrain, Canada, the US, Mexico, and the EU approved the vaccine for emergency use, while Saudi Arabia and Switzerland have given it full approval. Also in December, the World Health Organization granted the approval its first emergency use validation. In early 2021, Australia’s, Hong Kong’s, and Japan’s regulatory agencies also greenlighted the vaccine.  

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, the company announced that it would begin to test the vaccine on adolescents 12 years and older. On December 18, the FDA green-lighted the vaccine’s emergency use. Less than a week later, Canada’s regulatory agency did the same. In January, the EU, the UK, Israel, and Switzerland also followed suit.

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 Mexico, Chile, Russia, Pakistan, and Argentina. On June 25, following positive Phase 1 data published in The Lancet on May 22, China’s Central Military Commission approved the vaccine’s use by the country’s military for a year. In February, Mexico and Pakistan 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 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 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. 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, the UK, Argentina, El SalvadorKenya, and the Dominican Republic approved the vaccine’s emergency use. In January, 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, the World Health Organization granted the vaccine emergency use validation.

 

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 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, officials in Brazil announced results suggesting that the vaccine is 78 percent effective, though updated results released the following week pointed to an efficacy rate of closer to 50 percent, The New York Times reports. 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 underway in Bangladesh, Indonesia, and Turkey. A trial was 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.

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 has been approved to begin in Peru. In December, the UAE and China approved the vaccine for emergency use.

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. 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 Belarus, Argentina, Bolivia, Palestine, Algeria, Serbia, Venezuela, Paraguay, Turkmenistan, UAE, Hungary, Republic of Guinea, Tunisia, Armenia, Nicaragua, Mexico, Lebanon, Myanmar, Mongolia, Pakistan, Bahrain, Montenegro, Saint Vincent, and the Grenadines, Uzbekistan, Gabon, the Republic of San Marino, Ghana, Guyana, Kyrgyzstan, and Egypt have okayed its use.

Bharat Biotech

India

Inactivated SARS-CoV-2

In guinea pigs and mice, the vaccine was safe and elicited an immune response.

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.

ADDITIONAL VACCINES IN CLINICAL TRIALS

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, 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, 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. On October 12, the company announced that it had temporarily paused further dosing in all of these trials after a participant developed an unexplained illness, but less than two weeks later, it announced that it was preparing to resume these studies. In mid-November, the company announced a second global Phase 3 trial that would test two doses of the vaccine instead of one.

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 show the vaccine candidate to be safe and elicit neutralizing antibody levels greater than those provided by treatment with COVID-19 convalescent serum. In January, the company announced results from the Phase 3 trial in the UK, for which at least half of detected cases among participants were the new B.1.1.7 variant. The data suggest the vaccine is more than 95 percent effective against the original COVID-19 strain and more than 85 percent effective against B.1.1.7. Meanwhile, results from the Phase 2b trial in South Africa, where the B.1.351 variant was and still is circulating widely, suggest the vaccine is 60 percent effective in HIV-negative participants there.

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.

Suggest: Phase 1 and Phase 2/3 trials are underway 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 has been approved

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.

Phase 1/2 and Phase 2/3 trials are underway in Japan.

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. 

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

Animal studies showed that the vaccine candidate elicited high levels of neutralizing antibodies. Vaccinated animals had less virus in their lungs and suffered less lung damage, according to iChongqing. In late October, the company announced preliminary data from the ongoing early-stage trials that suggest the vaccine candidate is safe and elicits an immune response, according to China’s State Council.

Multiple Phase 1 trials, plus Phase 2 and Phase 3 trials, are ongoing in China.

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

Preclinical studies in multiple animal models suggest the vaccine candidate generates neutralizing antibodies and other immune responses.

A Phase 1 trial is underway in Taiwan.

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.

The vaccine candidate was safe and induced an immune response in animal models, according to the company.

Phase 1 trial underway in Italy

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

South Korea

Recombinant protein vaccine consisting of nanoparticles displaying the receptor binding domain of the SARS-CoV-2 spike protein

Preclinical studies posted as a preprint in August showed that it elicited high titers of neutralizing antibodies.

Phase 1 clinical trial set to begin in South 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.

Phase 1 and 2 complete; Phase 3 underway in Kazakhstan

Erciyes University

Turkey

Inactivated SARS-CoV-2

No serious side effects from Phase 1 trials were reported.

Phase 1 complete; Phase 2 underway

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

Attenuated or inactivated virus

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

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.S.S. Roosevelt who tested positive for COVID-19 had mostly mild symptoms, which some researchers suspect may have been due to administration of the MMR vaccine to all US Navy recruits.

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.

A Phase 3 trial has been approved to begin in Canada.

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 Altimmunes vaccine was approved for a Phase 2 trial; in fact, it is approved for Phase 1. The Scientist regrets the errors.