While the duration of post-vaccination immunity is being studied, booster vaccines may be needed, said David Kessler, chief scientific officer of Joe Biden’s Covid-19 Response Task Force, at a congressional committee meeting.
“We are studying the durability of the antibody response. So I think for planning purposes, just for planning purposes, I think we should expect that we may have to give a boost, “Kessler said.
“The current thinking is that those who are more vulnerable will have to go first,” he said.
Pfizer CEO Albert Burla also said it was “likely” that people would need a third dose of coronavirus vaccine within a year, with the possibility of annual revaccinations.
“We have to see what the sequence will be and how often we have to do that, we have to find out,” Burla told a CNBC reporter during an event with CVS Health. The CEO’s comments were published on Thursday, but were filmed two weeks ago.
Burla added: “The likely scenario is that there will probably be a need for a third dose, somewhere between six and 12 months, and then there will be an annual revaccination, but all this needs to be confirmed. Again, options will play a key role. “
Initial data show that the vaccines from Moderna and partners Pfizer and BioNTech SE retain most of their effectiveness for at least six months, although it is not yet determined how long.
Even if this protection lasts much longer than six months, experts say the rapidly spreading variants of coronavirus and others that may emerge may lead to the need for regular booster shots, similar to annual flu shots.
The United States is also monitoring infections in people who have been fully vaccinated, said Rochelle Valensky, director of the US Centers for Disease Control and Prevention, before a hearing of a subcommittee of the House of Commons.
So far, nearly 200 million doses of coronavirus vaccine have been distributed in the United States, and about 38 percent of the American population has received at least one shot.
Of the 77 million people vaccinated in the United States, there are 5,800 such outbreaks, Valenski said, including 396 people in need of hospitalization and 74 dead.
Walensky said some of these infections occurred because the vaccinated person did not receive a strong immune response. But the concern is that in some cases they occur in people infected with more contagious viral variants.
This month, Pfizer and BioNTech said their vaccine was about 91% effective in preventing Covid-19, citing updated data from studies that included more than 12,000 people completely inoculated for at least six months.