FDA Panel Says Omicron Shots Best for Autumn

11.07.2022 - While Europe still deliberates, and municipalities monitor sewage to pinpoint the further spread of coronavirus subvariants, especially those evolving from the omicron variant, the US Food and Drug Administration’s advisory panel has voted 19-2 to recommend that the government’s autumn vaccination program be based on the second generation mRNA vaccines developed by Pfizer/BioNTech and Moderna.

Both of the updated vaccines still lack FDA approval but there seems to be little doubt that they will be greenlit. The expert panel said it believes the new shots will provide more lasting protection against Covid, even if they may not produce as many antibodies as the first generation.

The new vaccines target the spike protein the virus uses to invade human cells. However, the current view is that the more the virus mutates the less successful these are at quickly recognizing and attacking the spike. To date, 30 omicron subvariants have been identified.  

Congressional Funding for vaccine purchase lags

Peter Marks, who heads the FDA’s vaccine division, told the committee that the better the match of the vaccine to the circulating strain, the more effectiveness and protection it should afford. But Marks said he is worried that, headed into recess, Congress may not appropriate money for vaccine purchases early enough to have sufficient supply to launch a timely campaign.

Without more funding, Ashish Jha, president Joe Biden’s new Covid response coordinator, has warned that vaccines might have to be rationed. Biden, he said, has carved $5 billion out of the White House emergency budget to kick-start negotiations with vaccine manufacturers. The funds are to be diverted from provisions for Covid tests and protective equipment.

Epidemiologists on both sides of the Atlantic are expecting a dangerous Covid surge this autumn as the weather cools. In a worst-case scenario, they fear the new wave could lead to more than 200,000 US deaths by March 2023.

According to the Centers for Disease Control and Prevention (CDC), three doses of the first-generation Covid vaccines offer only 19% protection against infection with omicron in adults ages 18 and older, 150 days or more after administration. The weakening may be due to omicron evolving into the more contagious subvariants, the CDC suspects.

The new Pfizer/BioNTech and Moderna vaccines were engineered to tackle the original omicron variant, BA 1, which is no longer circulating widely. BA 2 dominated this past spring, but the subvariants BA.4 and BA.5 are now rapidly gaining ground both in the US and Europe, as waste water analyses show.

Data presented by the world’s two biggest vaccine makers in small studies of several hundred people each showed that the new shots significantly boosted the immune response against BA.1 compared to the original shots targeting the Wuhan strain but despite a good immune response did not perform as well as hoped.

While some on the FDA panel thought it would be better to target BA.4 or BA.5 now, others noted that developing the manufacturing process for a vaccine aimed at a different subvariant would swallow up an additional three months, by which time there are likely to be new subvariants. The panel’s majority held that it would be better not to wait that long for subsequent testing and a rollout.

Beyond the mRNA vaccines, data submitted by Novavax to the FDA for the Emergency Use Authorization (EUA) of its protein-based Covid shot developed for the Wuhan strain is said to point to a strong immune response against omicron subvariants. This vaccine is seen as being close to getting the FDA’s nod.

Author: Dede Williams, Freelance Journalist