A booster dose of the Pfizer-BioNTech vaccine provides protection against omicron that is similar to a two-dose course against the original strain of the coronavirus, the companies said Wednesday based on preliminary lab studies.
The drugmakers also said persons who received a primary vaccination series saw a 25-fold drop in neutralizing antibody levels against omicron compared to the original strain, indicating two doses may not be enough to protect against any infection.
However, the companies feel confident that two doses will protect against severe disease from omicron, given behavior in certain immune-memory cells from the vaccine.
“Although two doses of the vaccine may still offer protection against severe disease caused by the omicron strain, it’s clear from these preliminary data that protection is improved with a third dose of our vaccine,” Pfizer Chairman and CEO Albert Bourla said. “Ensuring as many people as possible are fully vaccinated with the first two dose series and a booster remains the best course of action to prevent the spread of COVID-19.”
The data is based on lab samples that tested blood samples from vaccinated persons against the variant. Drugmakers are rushing to figure out if existing vaccines are working against the variant or if an omicron-specific shot is needed.
Pfizer said it will still work toward a specially tailored shot and could have it available by March “in the event that an adaption is needed to further increase the level and duration of protection.” The company said its production capacity of 4 billion doses in 2022 will not change.
Omicron burst into view last month after scientists in South Africa saw a surge in cases and found a number of alarming mutations of the new variant fueling the spread. There are signs the variant causes mild disease, but scientists want to see broader experience across age groups and populations.
Pfizer’s initial findings amplified the White House’s calls for widespread booster shots in fully vaccinated persons. Roughly a quarter of fully vaccinated persons have come forward for an extra dose.
“As the research on omicron comes in, one thing is clear: as the president has been saying, every adult should go get their booster shot,” President Biden’s chief of staff, Ron Klain, tweeted. “It’s free and convenient; available in more locations than ever, and new hours are being added at many sites!”
However, the findings could complicate the effort to improve the rate of initial vaccination, given signs that two doses may not protect against any infection from omicron.
Roughly six in 10 Americans are vaccinated with a primary series from two doses of the vaccines from Pfizer or Moderna or one dose of the Johnson & Johnson vaccine.
Some scientists want to change the definition of fully vaccinated — a move the Biden administration has resisted as it tries to get the unvaccinated to come forward.
“The arguments to require three shots to be deemed ‘fully vaccinated’ are now compelling. Let’s get it done before Omicron washes ashore in a major way,” tweeted Bob Wachter, chairman of the University of California, San Francisco. “Counting on lower severity to be our savior is a foolish risk to take.”
For more information, visit The Washington Times COVID-19 resource page.