It's looking more and more likely that ongoing immunization against the mutating coronavirus will be needed, and on Wednesday the CEO of Pfizer suggested that recipients of its vaccine will likely need a third booster dose next year.

It's been widely speculated that vaccination against the coronavirus isn't going to be a one-time deal, and given how uneven vaccine availability is around the globe, stamping the thing out permanently is likely to take years. Today, Pfizer CEO Albert Bourla confirmed that Pfizer's vaccine — and likely Moderna's given their similarities — is going to require a third booster dose, and the company is still working to figure out what the ideal timeframe for that will be.

"We need to see what would be the sequence, and for how often we need to do that, that remains to be seen," Bourla said in an interview with CNBC’s Bertha Coombs during an event with CVS Health. "A likely scenario is that there will be likely a need for a third dose, somewhere between six and 12 months and then from there, there will be an annual revaccination, but all of that needs to be confirmed."

For those who are just getting their first doses now, that will mean getting a booster shot either at the end of the year, or sometime next spring.

The official figures from the third-phase trial of Pfizer's vaccine say that it is 91% effective at guarding against COVID-19 infection, and more than 95% effective against severe disease up to six months after the second dose. But researchers are still trying to determine if immunity hangs on or actually starts to drop off after the six-month mark.

Moderna has already developed a booster shot that is specific to the B.1.351 or "South African" variant, and trials for that by the National Institutes for Health began this week. As Reuters reported, Moderna’s Chief Medical Officer Tal Zaks said this week that the company expects to have the booster shot ready for distribution by late 2021.

Both the Moderna and Pfizer vaccines have already proven effective against the B.1.1.7 or "U.K." variant, which is now the dominant strain in the U.S.

The Pfizer CEO's comments came on the same day that David Kessler, the Biden administration’s Covid response chief science officer who comes from UCSF, told the House Select Subcommittee on the Coronavirus Crisis that the need for booster shots is likely.

"We don’t know everything at this moment," he said, per CNBC. "We are studying the durability of the antibody response. It seems strong but there is some waning of that and no doubt the variants challenge... they make these vaccines work harder. So I think for planning purposes, planning purposes only, I think we should expect that we may have to boost."

Sure hope they fix the MyTurn site and all of its jankiness by the time we all have to do this again!

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