By Jared S. Hopkins 

Pfizer Inc. Chief Executive Albert Bourla said it is likely that people who receive Covid-19 vaccines will need booster shots within a year afterward, and then annual vaccinations, to maintain protection against the virus as it evolves.

"The variants will play a key role. It is extremely important to suppress the pool of people that can be susceptible to the virus," Mr. Bourla said during a virtual event hosted by CVS Health Corp. that aired Thursday but was recorded April 1.

"There are vaccines like polio where one dose is enough," Mr. Bourla said. "And there are vaccines like flu that you need every year. The Covid virus looks more like the influenza virus than the polio virus."

More research is required to confirm the need for annual booster shots, Mr. Bourla said. But he added that the need appeared likely given research so far.

The chief executive's comments come as the U.S. and other countries race to vaccinate as many people as possible and try to stay ahead of any variants that could evade the shots.

Researchers still don't know how long protection lasts from any of the Covid-19 vaccines, although they are studying the issue. New shots or boosters might be necessary, vaccine experts say, if the virus mutates significantly enough.

In the rush to introduce vaccines for the new virus, companies and other vaccine researchers didn't have time to determine how long shots would provide protection, or whether booster shots would be needed to ensure protection.

Pfizer and its partner, BioNTech SE, said recently that the shot remains highly effective six months after its second dose, and they hope to provide more information on protection beyond six months in the coming weeks.

Health regulators began authorizing use of Pfizer-BioNTech's shot in December and the vaccine has been rolled out in dozens of countries. Since then, millions of people across the world have been vaccinated.

Mr. Bourla and other Pfizer executives have said since last year that annual or seasonal shots were likely. In February, Pfizer and BioNTech began a study testing in people whether a third dose of the companies' inoculation can protect against emerging variant strains.

Moderna Inc. has also begun studying whether a booster shot of its vaccine is effective against a variant of the virus.

The Pfizer-BioNTech vaccine is based on a new gene-based technology called messenger RNA. The likelihood that periodic Covid-19 shots will be needed is one reason Pfizer executives have said the company plans to expand its vaccine business by becoming a leader in mRNA.

Write to Jared S. Hopkins at


(END) Dow Jones Newswires

April 15, 2021 17:16 ET (21:16 GMT)

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