- Further documents from FDA advisory committee regarding COVID-19 vaccine booster shots published Wednesday
- In one of the documents, Pfizer released new data suggesting the efficacy of two doses ranged from 96.2% to 83.7% after six months.
- The third dose appeared to increase antibody levels between five-fold and 12-fold, especially in older adults.
- In a separate briefing document, FDA officials expressed doubts about the need for additional doses.
- He said the vaccines are still highly effective against serious illness and death and that studies on the third dose have produced conflicting results.
Doubts remain over COVID-19 vaccine booster shots ahead of an advisory committee meeting on Friday, despite the US Food and Drug Administration (FDA) Pfizer-BioNtech releasing new data suggesting their need.
The Vaccines and Related Biological Products Advisory Committee (VRBPAC) will meet at the end of the week to discuss data on a possible third dose.
Members will vote on whether booster doses are safe and effective and whether they should be approved for all Americans.
Currently, the third dose is only approved in the US for immunocompromised people 12 years of age and older.
new data Pfizer, published on Wednesday, shows that the efficacy of the regular two-dose regimen drops from 96.2 percent to 83.7 percent after six months, but the booster dose seems to increase the immune response.
However, in a different briefing document Also published on Wednesday, FDA officials expressed doubts about the need for additional doses.
Further documents from the FDA advisory committee regarding the COVID-19 vaccine booster shots were published Wednesday. Pictured: A nurse gives Lana Sellers a COVID-19 booster shot on August 18 in Altamonte Springs, Florida
Pfizer released new data suggesting the effectiveness of two doses dropped from 96.2% to 83.7% after six months, but the third dose appeared to boost antibody levels (above) between five-fold and 12-fold , especially in older adults
Last month, boosters were approved for immunocompromised Americans who received the Pfizer or Moderna vaccine after data showed they were less likely to develop high antibody levels after two doses.
At the time, Pfizer said its initial data showed that those who received a booster dose between six and 12 months after their last dose had a higher level of protection.
The company filed for emergency use authorization for the booster dose in late August and submitted the data, which were made public on Wednesday.
Documents show that protection from two doses of the Pfizer vaccine drops from 96.2 percent at seven days after two months to 90.1 percent after two months and to 83.7 percent after six months.
What’s more, he cited data from Israel showing people who were fully vaccinated in January 2021 had a 2.26-fold increased risk for breakthrough infection compared to those who were fully vaccinated in April 2021.
Another Israeli study mentioned in the documents showed that the effectiveness against infection was 39 percent and against symptomatic disease was 40 percent from June 20, 2021 to July 17, 2021, when the delta variant was the dominant strain.
In comparison, between January and April, these rates were 95 per cent or more.
Antibody levels increased 3.1-fold at day 28 after dose three (far right) compared to day five after dose 2 (second from left).
The researchers say that even though Delta was the dominant strain during the summer, the decreasing percentage is a sign of reduced effectiveness of the vaccine and not the variant.
‘As noted … emerging data suggest that vaccine protection may decrease at about six to eight months after the second dose, and evidence is building to suggest that COVID-19 The administration of booster doses of mRNA vaccines is potentially an urgently emerging public health problem,’ the authors wrote.
The team also released a clinical trail to the data that included 23 Participants who took part in Pfizer’s early-stage trials last year.
Each had received two doses of the vaccine and was given a booster dose at least six months later.
11 of the participants were in Young adult groups aged 18 to 55 and 12 were aged 65 to 85.
After the third dose, neutralizing antibodies against the original strain of the virus increased five-fold in the 18 to 55 age group and seven-fold in the 65 to 85 age group.
Against the delta variant, antibody levels after the booster shot increased five-fold in the younger adult group and 12-fold in the older adult group.
In a separate document, FDA scientists wrote in a skeptical tone about the need for booster shots.
Overall, the data indicate that currently US-licensed or authorized COVID-19 vaccines still provide protection against serious COVID-19 illness and death in the United States, the scientists wrote.
He added that studies on booster doses have presented conflicting findings and that there are ‘known and unknown biases that may affect their reliability’.
Additionally, the scientists considered whether the third dose would increase the rates of myocarditis and pericarditis – rare heart inflammations seen in young men – after two doses.
‘It is not currently known whether the risk of myocarditis/pericarditis or other adverse reactions will be increased following a booster dose,’ they wrote.
‘These risks and associated uncertainties should be considered when assessing the benefits and risks.’