Join getAbstract to access the summary!

What Landmark COVID Vaccine Results Mean for the Pandemic

Join getAbstract to access the summary!

What Landmark COVID Vaccine Results Mean for the Pandemic

Scientists welcome the first compelling evidence that vaccines can prevent COVID-19 – but questions remain about how much protection they offer, and for how long.


5 min read
4 take-aways
Audio & text

What's inside?

No one is certain who the COVID-19 vaccines best protect, and how long they’ll last.

Editorial Rating



  • Analytical
  • Scientific
  • Hot Topic


While preliminary trial results for several COVID-19 vaccines look promising, scientists await more detailed data to ascertain their actual efficacy. Pfizer and Moderna vaccines have shown over 90% effectiveness in preventing the disease, while some criticize Russia’s Sputnik V data as sparse and rushed. Questions persist about whether the vaccines will lesson viral contagiousness, work the same in everyone, or remain effective for long periods of time. But the race is on to get vaccines into the arms of a world full of people desperate for a return to normalcy.


The world awaits final trial results for several promising COVID-19 vaccines.

Scientists are encouraged by preliminary trial results of COVID-19 vaccines, which involve large numbers of human participants. Three companies vying to distribute their vaccines first have released phase III data. Pfizer, Moderna and a group of Russian developers claim their products are more than 90% effective at preventing COVID-19. The results don’t reveal whether they block disease transmission, nor how they work in various people.

Participants taking the experimental vaccine are followed for weeks to determine whether they suffer virus symptoms, compared with a placebo group. Pfizer, which is developing its vaccine with German firm BioNTech, says its two-dose vaccine is more than 90% effective. Only 94 cases of COVID-19 occurred in a group of 43,538 trial subjects, evaluated a week after the second dose. The trial began on July 27 and continues...

About the Author

Ewen Callaway is a London-based writer for Nature.

Comment on this summary