Written by LAURAN NEERGAARD

Pfizer said Wednesday that a booster dose of its COVID-19 vaccine may offer important protection against the new omicron variant even though the initial two doses appear significantly less effective.

Pfizer and its partner BioNTech said that while two doses may not be protective enough to prevent infection, lab tests showed a booster increased by 25-fold people’s levels of virus-fighting antibodies against the omicron variant.

Blood samples taken a month after a booster showed people harbored levels of omicron-neutralizing antibodies that were similar to amounts proven protective against earlier variants after two doses.

Scientists don’t yet know how big a threat the omicron variant really is. Currently the extra-contagious delta variant is responsible for most of the COVID-19 cases in the U.S. and other countries.

But the omicron variant, discovered late last month, carries an unusually large number of mutations and scientists are racing to learn how easily it spreads, whether it causes illness that is more serious or milder than other coronavirus types — and how much it might evade the protection of prior vaccinations.

Pfizer’s findings, announced in a press release, are preliminary and haven’t yet undergone scientific review. But they’re the first from a vaccine maker examining whether the booster doses that health authorities are urging people to get may indeed make an important difference.

Scientists have speculated that the high jump in antibodies that comes with a third dose of COVID-19 vaccines might be enough to counter any decrease in effectiveness.

Pfizer and BioNTech already are working to create an omicron-specific vaccine in case it’s needed.

Antibody levels predict how well a vaccine may prevent infection with the coronavirus but they are just one layer of the immune system’s defenses. Pfizer said two doses of the vaccine should still protect against severe disease, because the mutations in omicron don’t appear to hamper one of those other defenses, T cells that fight the virus after infection sets in.

“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 maximized with a third dose of our vaccine,” Pfizer CEO Albert Bourla said in a statement.

Pfizer’s announcement had an immediate impact on U.S. markets. Futures that had pointed to a lower open reversed course in seconds and swung solidly to the positive with the Dow jumping almost 200 points.

 

Photo via AP Photo/Steven Senne.

 

Related Stories
‹
Moderna Sues Pfizer Over Patents Behind COVID-19 Vaccine
Written by TOM MURPHY COVID-19 vaccine maker Moderna is suing Pfizer and the German drugmaker BioNTech, accusing its main competitors of copying Moderna’s technology in order to make their own vaccine. Moderna said Friday that Pfizer and BioNTech’s vaccine Comirnaty infringes on patents Moderna filed several years ago protecting the technology behind its preventive shot, […]
Pfizer COVID-19 Shot Appears Effective For Kids Under 5
Written by MATTHEW PERRONE and MIKE STOBBE Federal health officials said Sunday that kid-sized doses of Pfizer’s COVID-19 vaccines appear to be safe and effective for kids under 5, a key step toward a long-awaited decision to begin vaccinating the youngest American children. The Food and Drug Administration posted its analysis of the Pfizer shot ahead […]
Moderna Seeks FDA Authorization for 4th Dose of COVID Shot
Written by ZEKE MILLER Drugmaker Moderna asked the Food and Drug Administration on Thursday to authorize a fourth shot of its COVID-19 vaccine as a booster dose for all adults. The request is broader than rival pharmaceutical company Pfizer’s request earlier this week for the regulator to approve a booster shot for all seniors. In […]
US Expands COVID Boosters to All Adults, Final Hurdle Ahead
Written by LAURAN NEERGAARD and MATTHEW PERRONE U.S. regulators on Friday moved to open up COVID-19 booster shots to all adults, expanding the government’s campaign to shore up protection and get ahead of rising coronavirus cases that may worsen with the holidays. Pfizer and Moderna announced the Food and Drug Administration’s decision after at least […]
US Gives Final Clearance to COVID-19 Shots for Kids 5 to 11
U.S. health officials on Tuesday gave the final signoff to Pfizer’s kid-size COVID-19 shot, a milestone that opens a major expansion of the nation’s vaccination campaign to children as young as 5. The Food and Drug Administration already authorized the shots for children ages 5 to 11 — doses just a third of the amount […]
Pfizer Asks US To Allow COVID Shots for Kids Ages 5 to 11
Written by LAURAN NEERGAARD Pfizer asked the U.S. government Thursday to allow use of its COVID-19 vaccine in children ages 5 to 11 — and if regulators agree, shots could begin within a matter of weeks. Many parents and pediatricians are clamoring for protection for children younger than 12, today’s age cutoff for the vaccine […]
U.S. Parents Excited Over Prospect of Virus Shots for Children
Written by HEATHER HOLLINGSWORTH and TODD RICHMOND After more than a year of fretting over her 13-year son with a rare liver disease, Heather Ousley broke into tears when she learned that he and millions of other youngsters could soon be eligible for the COVID-19 vaccine. “This day is the best day in the history of […]
EU Moves Toward Stricter Export Controls for COVID Vaccines
Written by RAF CASERT The European Union is moving toward stricter export controls to ensure that there are more COVID-19 shot supplies for the bloc which should boost its flagging vaccine drive at a time of another surge of the coronavirus pandemic on the continent. The EU’s executive body said Wednesday on the eve of a […]
U.S.: AstraZeneca Results May Have Included Outdated Info
Results from a U.S. trial of AstraZeneca’s COVID-19 vaccine may have included “outdated information” and that could mean the company provided an incomplete view of efficacy data, American federal health officials said early Tuesday. AstraZeneca said in a statement that the data it released Monday included cases up to Feb. 17, as the study rules […]
Astrazeneca: U.S. Data Shows Vaccine Effective for All Ages
Written by MARIA CHENG and LAURAN NEERGAARD AstraZeneca’s COVID-19 vaccine provided strong protection against sickness and eliminated hospitalizations and deaths from the disease across all age groups in a late-stage study in the United States, the company announced Monday. AstraZeneca said its experts did not identify any safety concerns related to the vaccine, including finding no […]
›