It’s unclear how long protections against infection will last from the initial vaccinations, and health authorities say additional jabs will likely be necessary.

Mix-and-match shots could simplify vaccine rollout and stimulate more-robust immune responses. Ongoing clinical trials will soon give answers.

Engineered viruses that don’t replicate provide a tractable model for scientists to safely study SARS-CoV-2, including research into vaccine efficacy and emerging variants.

Facing new variants of SARS-CoV-2, some vaccines may offer more robust protection or be more easily redesigned to target them.

Johnson & Johnson’s vaccine is less effective at preventing COVID-19 than other approved vaccines are, but experts say it could still be an important tool in curbing the pandemic.

Long before Moderna’s and Pfizer’s COVID-19 shots, scientists had been considering the use of genetically encoded vaccines in the fight against infectious diseases, cancer, and more.

A recent study elucidates some of the changes that occur in the body after inoculation with a tuberculosis vaccine.

As researchers test existing vaccines for nonspecific protection against COVID-19, immunologists are working to understand how some inoculations protect against pathogens they weren’t designed to fend off.

The company voluntarily paused its studies, including one in Phase 3, after an unexplained illness in a patient.