Covid vaccine renewal may be required to ensure efficacy: FDA

According to the Food and Drug Administration, the currently approved Covid-19 vaccine may need to be renewed to ensure a high level of protection as the virus continues to evolve.

FDA, In the briefing document Announced before this week’s advisory board, scientists have said they do not yet fully understand the efficacy of Covid variants and vaccines. For example, mutations into the spike protein that the virus uses to invade human cells reduce the effectiveness of current vaccines. This is because today’s Covid Shot was developed to target the peplomer of the original strain of the virus that emerged in Wuhan, China in late 2019.

On Wednesday, the FDA’s Advisory Board of External Vaccine Experts will discuss how the United States recommends developing a transparent process and changing the composition of current vaccines as needed. Pfizer When modern We are conducting clinical trials of vaccines based on the Omicron variant, the predominant version of the virus worldwide. Omicron and its rapidly spreading subvariant BA.2 have numerous mutations that break through the vaccine and enhance its ability to cause infections that normally cause mild illness.

Effectiveness of Pfizer Also Modern The double dose vaccine for mild illness caused by Omicron decreased from 70% to only 10% 25 weeks after the second dose. According to UK Health Security Agency. The third dose increases protection to 75% in about 4 weeks, but decreases from 25% to 40% after 15 weeks. The effectiveness of the two vaccinations for hospitalization with Omicron decreased from 71% to 54% after 5 months. According to the Centers for Disease Control and Prevention.. Protection increased to 91% on the third shot and dropped to 78% after 4 months.

When the vaccines were first approved in December 2020, they were 90% effective in preventing symptom-causing infections. According to the CDC.

The FDA said in a briefing document that it is not possible to predict which variants will prevail for how long, and will put a practical limit on how often vaccines can be changed. Drug regulators also said that clinical trial data should be reviewed before approving changes in vaccine composition to ensure that they are effective and do not raise safety concerns.

The FDA has proposed to use the process of updating the influenza vaccine as a guide on how the Covid vaccine can be changed in the future. The World Health Organization meets twice a year to analyze circulating influenza variants and make recommendations on vaccine composition.

The FDA’s external expert, Vaccine and Related Biopharmaceutical Advisory Board, will meet to make its own recommendations, which the United States will then accept. The FDA is not bound by the WHO influenza vaccine recommendations, but drug regulators usually come to the same conclusion.

However, the FDA said in its briefing document that it may be necessary to consider renewing the Covid vaccine without prior WHO recommendations. It’s unclear whether Covid’s dissemination will follow patterns that allow global recommendations for vaccine renewal, the FDA said in a statement.

Wednesday’s FDA Advisory Board will also discuss at some point whether the fourth Covid shot is justified for young people in the United States.Drug regulator Fourth dose of Pfizer and Moderna approved for adults over 50 years of age Last week, based on data from Israel, additional shots show a reduction in elderly mortality. The FDA Commission did not meet to make a recommendation prior to its decision, and it will not vote on any recommendations on Wednesday.

Dr. Peter Markes, Head of the FDA Office for Vaccine Safety and Efficacy, said last week: Additional booster immunity may be needed in the fall.. Public health experts and epidemiologists say the United States could face another wave of Covid infections at that time as immunity from the vaccine weakens and people move indoors to escape the cold weather. increase.