Pfizer Booster: Will It Get Acceptance in the US?
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(CNN) -
Vaccine advisers from the U.S. Food and Drug Administration (FDA) are meeting Thursday and Friday to address the next round of questions about booster vaccines. for covid-19, and you'll see the first data on mixed booster doses.
This Thursday they will focus on Moderna's request to add a booster dose to its two-dose vaccine schedule.
On Friday, meanwhile, they will study Johnson & Johnson's request for the reinforcements.
Only after these two issues have been resolved will members of the FDA Vaccines and Related Biologics Advisory Committee, or VRBPAC, move on to discussing mix-and-match boosters.
It's one of the main questions raised about vaccines since three different products arrived in the United States: is it safe, and even desirable, to mix different types of vaccines?
Researchers have tried various combinations.
Keys to understanding Pfizer's recommendation on reinforcement 1:05
"We started by examining people who had previously received the Johnson & Johnson, Moderna, and Pfizer vaccines and boosted them with an additional dose of Moderna vaccine," Dr. Angela Branche, associate professor at the School of Medicine, told CNN. from the University of Rochester, which is helping to run some of the clinical trials in which booster doses are mixed.
Researchers have also tried boosting volunteers with the Pfizer and Johnson & Johnson vaccine.
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A preliminary printout of that study from the National Institutes of Health published online Wednesday says the mix of boosters produced a robust immune response.
The study, which involved more than 400 people, has yet to be reviewed or published.
A study concludes that the application of a booster other than the initial covid-19 vaccine is safe and produces a strong immune response
For participants who initially received the Johnson & Johnson single vaccine, a booster of the Pfizer or Moderna vaccine appeared to provide a stronger antibody response.
People who initially received the Pfizer or Moderna vaccine appeared to have a comparable response with either booster.
The study also revealed that it appears to be safe for people to receive a different booster of the COVID-19 vaccine than they initially received.
Side effects were similar to those experienced with the initial vaccine.
Half of the study participants experienced some effects, such as injection site pain, tiredness, nausea, chills, headache, and muscle pain.
Most of the symptoms were felt between one and three days after the boost.
None of the side effects were serious.
"Reactogenicity and adverse effects were similar in all booster groups," the study says.
"These data suggest that if a booster vaccine is approved or licensed, it will generate an immune response regardless of the primary covid-19 vaccination regimen."
Which booster shot is better?
During the meeting it will be discussed whether there is a difference in the quality and quantity of the antibodies generated with the booster of a different type of vaccine, and whether it is important to wait for a different amount of time.
Last month, Pfizer received an emergency use authorization for a booster dose of its vaccine for certain people who have been at least six months after their initial two doses.
Moderna has drafted its authorization request to reflect the European authorization granted to Pfizer.
Request EU authorization for a half-dose booster, but only in people who received their first two doses at least six months ago and who are 65 years or older, at high risk of severe COVID-19, or those whose exposure at work or in their environment puts them at high risk of serious complications from the infection.
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Moderna has far less data than Pfizer to show that its vaccine's immunity is waning.
In fact, several studies have indicated that Moderna's vaccine provides somewhat greater protection than Pfizer's.
A comparative study led by the US Centers for Disease Control and Prevention (CDC) concluded that Moderna's vaccine was slightly more effective than Pfizer's in real life at the time to keep people out of the hospital.
Is immunity lowered by Moderna's vaccine?
FDA staff were circumspect in documents released before Thursday's meeting.
"Some real-world efficacy studies have suggested a decrease in the efficacy of the Modern covid-19 vaccine over time against symptomatic infection or against the delta variant, while others have not. However, overall, data indicates that currently licensed or licensed COVID-19 vaccines in the United States continue to offer protection against severe COVID-19 disease and death in the United States, "they wrote.
"There are many potentially relevant studies, but the FDA has not independently reviewed or verified the underlying data or their conclusions," he added.
Should you get a covid-19 booster now?
An expert thinks
As with the Pfizer request, the Israeli investigators will report on what has been going on there.
Israel has been conducting in-depth studies on lowering immunity, although the majority of the Israeli population has received the Pfizer vaccine.
Dr. Sharon Alroy-Preiss, director of public health services at the Israel Ministry of Health, and Ron Milo, professor at the Weizmann Institute in Israel, who spoke in favor of Pfizer's request for reinforcement, are scheduled to speak before the VRBPAC this Thursday.
The committee will vote on Moderna's application and the session is scheduled to adjourn at 4:45 p.m. ET on Thursday.
What is known about the Janssen vaccine
Johnson & Johnson has been less precise in its request for booster doses.
The company has said it wants to leave the details to the FDA.
"Based on recent data, it can be assumed that the administration of the booster dose will lead to increased protection against symptomatic infection, greater strength and breadth of immune responses against current variants, and increased magnitude of protection against severe disease in all populations, "the company says in its application.
"The booster dose may also increase the likelihood of protection against future variants of interest. A booster dose is recommended at 6 months or more, depending on the intensity of the immune responses, although a booster dose may be given starting 2 months. The need for a booster dose and / or its timing will depend on the local / epidemiological situation and the needs of specific individuals / populations. "
They confirm the decrease in immunity of the Pfizer vaccine 0:41
The FDA said it had not had time to verify J & J's analysis and would ask the committee to decide whether the company had submitted enough information to recommend boosters at two or six months.
The committee is scheduled to vote at 3:15 p.m. ET on Friday on whether to recommend the authorization of a booster dose of Johnson & Johnson's Janssen vaccine and, if so, for whom and when.
Waiting can be profitable
"In general, the longer you wait, the better the boost," Dr. Dan Barouch of Harvard Medical School and director of the Virology and Vaccine Research Center at Beth Israel Deaconess Medical Center told CNN.
Barouch is scheduled to speak to the VRBPAC this Friday.
The committee will meet again at 3:30 pm on Friday to discuss the issue of mixed reinforcements, although a vote on this issue is not scheduled.
Branche of Rochester thinks the data may indicate that mixing vaccine types for a booster could offer an advantage.
But Barouch, who has also studied mixed booster doses, said there isn't enough data to say so yet.
What vaccines can be combined?
Dr. Huerta responds 5:00
"I think there is a lot of potential for mixed regimes, but the data sets to date are very small," he told CNN.
Both Moderna and Pfizer use mRNA technology, a genetic material called messenger RNA that is administered directly to cells to instruct the body to make small pieces of the virus to stimulate the immune response.
The Janssen vaccine is a vector vaccine, which uses another virus, called adenovirus, which is paralyzed so that it cannot replicate, to carry pieces of the coronavirus and stimulate the response.
According to Branche, these two different delivery methods stimulate the immune system in slightly different ways.
"I think the data will show that the boost is certainly very effective in providing additional and longer protection," he said.
Covid-19 vaccine against covid-19