CDC panel recommends new omicron Covid boosters with injections set to begin next week

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The Centers for Disease Control and Prevention’s independent committee on vaccines has recommended reformulated booster shots that target the latest omicron subvariants.

The panel voted 13 to 1 on Thursday in favor of the injections after reviewing available data on safety and effectiveness in a nearly seven-hour meeting. CDC Director Dr. Rochelle Walensky still needs to give final approval before pharmacies can begin administering the boosters, but her approval should follow quickly.

Pfizeromicron boosters are intended for ages 12 and older, while ModernUpdated snaps are intended for adults 18 and older. Eligible age groups can receive the boosters at least two months after completing their main streak or their most recent booster with old shots.

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Pfizer plans to ask the Food and Drug Administration to also authorize the new boosters for children ages 5 to 11 in early October, company executives told the committee Thursday.

The original vaccines will no longer be used as a booster in people aged 12 and over now that the reformulated shots are going live.

Public health officials expect another wave of Covd infection this fall as immunity to older vaccines wanes, more contagious omicron subvariants spread and people spend more time indoors as the weather cools and families gather for the holidays.

The CDC and FDA hope the new boosters will provide longer-lasting protection against infections, minor illnesses, and serious illnesses. The reformulated shots target omicron BA.5, the dominant Covid variant as well as the strain that emerged in China more than two years ago.

So far, the United States has obtained 171 million doses of the new boosters from Pfizer and Moderna. More than 200 million people are eligible for the injections, according to the CDC. Dr. Sara Oliver, a CDC official, told the committee on Thursday that there should be enough vaccines to meet demand this fall.

No human data omicron BA.5

There’s no human test data on the new BA.5 boosters, so it’s unclear how they will perform in the real world. The CDC and FDA used human data from clinical trials for injections targeting the original version of omicron, BA.1, which elicited a stronger immune response than older vaccines.

Pfizer and Moderna were originally developing omicron boosters to target BA.1, but the FDA asked the companies to shift gears in June and develop BA.5 injections instead after the subvariant became mainstream . The decision to focus on BA.5 did not allow enough time to wait for data from human trials before rolling out a vaccine in the fall.

The lack of human data for the BA.5 vaccines has sparked some controversy, but Dr. Peter Marks, a senior FDA official, said the agency followed the same process used for years with strain changes. for flu shots. Marks said Wednesday that flu vaccine strains are also modified without human clinical data.

Dr. Pablo Sanchez, the only committee member to vote against the injections, called the recommendation premature and said the United States should have waited for human data before proceeding with the recalls.

“There’s a lot of vaccine hesitancy already — we need the human data,” said Sanchez, professor of pediatrics at Ohio State University. But Sanchez said he thought the new boosters were safe and he would likely get one himself.

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Panel member Dr. Oliver Brooks, chief medical officer of Watts HealthCare Corporation in Los Angeles, asked why the FDA decided to go with a BA.5 vaccine when clinical data is available for BA.1 vaccines. that vaccine makers were originally developing. Brooks ended up voting in favor of the firings.

But Dr Sarah Long, also a committee member, said there was no reason to expect BA.5 boosters to be inferior to older vaccines as they also include the original strain of Covid, and they have the potential to reduce hospitalizations and deaths as we approach fall and winter. Long also upvoted.

Mouse studies

FDA and CDC officials have stated that the omicron BA.1 and omicron BA.5 boosters are similar enough that the immune response data from the BA.1 injection gives a good indication of the performance of the BA injections. 5. Omicron BA.1 and BA.5 are closely related with a difference of four mutations, according to Dr. Jacqueline Miller, who works in vaccine development at Moderna.

Moderna completed clinical trial enrollment on the BA.5 injections last week and is expected to have results by the end of the year, Miller told the CDC committee on Thursday. Pfizer’s clinical trial is also ongoing, although the company did not say when it expected results.

Health agencies have also reviewed data on BA.5 injections from mouse studies. Moderna presented data showing that injections of BA.5 more than quadrupled antibodies in mice compared to older injections. The mice express the same cellular protein as humans on which the virus latches. Pfizer’s BA.5 booster increased antibodies 2.6 times in mice compared to the original vaccine.


The most common side effects in human trials of BA.1 injections were pain, redness, swelling at the injection site, fatigue, headache, muscle pain, joint pain, chills, nausea, vomiting and fever, according to the FDA.

Oliver, the CDC official, told the committee that health officials do not expect any difference in the safety profile of the BA.1 and BA.5 injections given that the subvariants only differ by a few mutations.

But Oliver noted that the risk of myocarditis following a BA.5 booster shot is unknown. There is an elevated risk of myocarditis in young men and adolescents after the second dose of vaccines from Pfizer and Moderna, but the risk of myocarditis due to Covid infection is higher, according to the CDC.

“We know the risk of myocarditis is unknown but anticipate a risk similar to that seen after monovalent vaccines,” Oliver said. Monovalent vaccines are the older vaccines that have been given to millions of people in the United States over the past two years.

Old vaccines lose their effectiveness

The original vaccines, which were first licensed in December 2020, no longer offer significant protection against infection because the virus has mutated so much over the past two years. The injections were developed against the first strain to appear in China, so they are no longer suitable for targeting the spreading omicron subvariants.

Infections, hospitalizations and deaths have fallen dramatically since the massive wave of omicron infections last winter, but have plateaued this summer at a stubbornly high level. Omicron BA.5 is the most contagious and immune variant to date, and breakthrough infections have become increasingly common as a result.

The effectiveness of older vaccines against hospitalization also declined after omicron BA.5 became dominant. A third dose was 77% effective during preventive hospitalization four months after receiving the vaccine, but protection declined after 120 days by up to 34%, according to CDC data. A fourth dose in people aged 50 and over was 56% effective in preventing hospitalization after four months.

Covid deaths and hospitalizations among people aged 65 and older have increased since April, according to Heather Scobie, a CDC epidemiologist who presented data at Thursday’s meeting. Deaths have increased particularly among people aged 75 and over, Scobie said.

The CDC has shifted to a more targeted public health response with an emphasis on protecting the most vulnerable — the elderly, those with serious medical conditions, and those with weakened immune systems. Although there is no data on the actual effectiveness of the new boosters, the United States is moving quickly to roll them out in hopes they will protect people this fall.

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