How Nine Covid-19 Vaccines Work
Researchers are testing 64 coronavirus vaccines in clinical trials on humans. Here are explanations about how nine of the leading vaccines work.
Messenger RNA Vaccines
How Moderna’s Vaccine Works
The vaccine, known as mRNA-1273, has been approved in Canada and authorized for emergency use in the United States, Israel and the European Union. Clinical trials showed the vaccine has an efficacy of 94.5 percent.
Adenovirus-Based Vaccines
New · How the Gamaleya Vaccine Works
The vaccine, known as Sputnik V or Gam-Covid-Vac, is a combination of two different Adenoviruses, Ad26 and Ad5. The vaccine is in use in Russia, Belarus and several other countries. A Phase 3 trial showed an efficacy of 91 percent.
Protein-Based Vaccines
Inactivated Coronavirus Vaccines
How the Sinopharm Vaccine Works
The vaccine, known as BBIBP-CorV, is approved in China, Bahrain and the United Arab Emirates. Sinopharm says the vaccine has an efficacy rate of 79.34 percent.
New · How Bharat Biotech’s Vaccine Works
The vaccine, known as Covaxin, is authorized for emergency use in India, despite a lack of published Phase 3 trial results. The vaccine’s efficacy is not yet known.
See the Coronavirus Vaccine Tracker for the status of other vaccines in development.
Tracking the Coronavirus