Moderna plans to seek authorization from FDA for Covid vaccine booster by the summer

Moderna plans to get authorization from the Food and Drug Administration for its vaccine booster Covid 19 by the summer, the company s chief medical officer said on Thursday. The time frame means that the targeted vaccine may not be available to the public until the second half of the year.

Moderna's chief medical officer, Dr. Paul Burton, told NBC News that the company is thinking ahead to the second half of 2022 when omicron may still be widely circulated.

Data shows that Moderna's original vaccine booster still provides strong protection against certain variants of the coronaviruses, like delta. Burton said there was a bit less against the extremely contagious omicron variant after six months.

He said that we're going to do the work now, referring to the omicron-specific vaccine. We're going to generate it, we're going to produce it. We would be certain that we would be filing it a different version of it by the summer. Moderna started clinical trials for the omicron-specific booster on Wednesday.

Pfizer and BioNTech are testing their version of an omicron-specific vaccine, which could be ready to launch as early as March.

One of the benefits of mRNA vaccines is how quickly they can be made, but scientists still have to demonstrate that the shots actually work and prepare data to be scrutinized by federal regulators.

Some health experts have questioned whether omicron-specific shots will be necessary in the second half of the year, or if it will be too late, because omicron-fueled cases have begun to decline in the United States, and it is always possible that a new and more virulent variant could emerge. There is a push for next generation Covid vaccines to be multivalent, meaning they would protect against multiple variants at once.

Scientists have already detected a subvariant of the omicron, known as BA. It is still not known whether it is more contagious or causes more severe disease, according to experts.

Dr. Jesse Goodman, an infectious disease specialist at Georgetown University Medical Center and a former chief scientist with the FDA, said it was important to have an omicron-specific vaccine available because another dangerous variant could emerge that is more closely related to omicron than to prior strains.

The existing vaccines still target the original strain first identified in late 2019.

Goodman said that Moderna and Pfizer's trials could answer questions, including whether or not an omicron-specific vaccine or future vaccines like it can generate broadly reactive antibodies that can also target earlier strains like delta and beta.

He said it could be that it would never be used.

Covid vaccines for the antibody-evading beta variant, for example, were later found to be unnecessary after that variant didn't gain a foothold and spread widely across the globe.

Anna Durbin, a vaccine researcher at Johns Hopkins University, agreed that Moderna should still pursue the modified vaccine, adding that the process for selecting the right Covid booster could be similar to the one for the annual flu shot.

Scientists select three to four influenza strains each year and select three to four that they think will be circulating widely to include in the flu vaccine.

Burton said Thursday that the company will test a 50 microgram dose of the omicron-specific vaccine, the same dosage as in the existing booster shot, as well as a 100 microgram dose, the same dosage given in the first two shots of the primary series.

He said it will take a couple more months before the modified vaccine can be tested in people and the company can analyze the blood samples. He added that the final decision to seek the FDA's approval will be influenced by science and discussions with federal regulators.

He said that the company is looking into vaccines that can target multiple variants at once or multiple viruses, like the coronaviruses and influenza, in a single shot.

Moderna could begin testing its shot for Covid and the flu late this year, and it could be ready to launch in late 2023, he said.