FDA advisers recommend Covid vaccine updates to target new strains

Yahoo

23-05-2025

The Food and Drug Administration's advisory committee unanimously recommended that newest vaccines for Covid should be updated to target a variant of strains currently on the rise, during a meeting on Thursday – the first since the Trump administration took office.
The meeting focused on selecting a Covid strain to target in upcoming vaccines as well as formalizing new FDA rules that limit vaccine access to Americans.
Though it was intended to help advisers recommend strains for the upcoming year's booster shots to the FDA, the meeting came in the context of upheaval at the federal health department.
'We have a very specific and important goal,' said Arnold Monto, professor of epidemiology at the University of Michigan School of Public Health and chair of the committee. 'We are asking for guidance to help the FDA decide what strain to select for going forward.'
On Tuesday, Trump administration health officials announced they would take a less 'aggressive' approach to booster shots and require placebo-controlled trials for healthy individuals younger than 65.
'As many of you all know, this week in the New England Journal of Medicine the commissioner and I revealed a framework for Covid-19 policy,' said Vinay Prasad, the director of the Center for Biologics Evaluation and Research at the Food and Drug Administration, which oversees vaccines.
He said the new framework would generate 'important and relevant information for the American people', referring to new trial requirements.
The plan includes limiting access to Covid-19 vaccines to people 65 and older and others who are considered high-risk, as well as requiring manufacturers to conduct clinical trials to show whether the vaccines benefit healthy younger adults and children.
The FDA's vaccines and related biological products advisory committee, a group of independent vaccine experts, concluded their all-day meeting by unanimously recommending that Covid vaccines for the 2025-2026 period target newer strains of the JN.1 variant. Although their decision is not binding, the FDA usually takes their advice.
Currently, the US has three Covid-19 vaccines approved – Pfizer-BioNTech, Moderna and Novavax.
Typically, the FDA advisory committee would recommend formulations for shots and whether they should be approved, with a separate advisory committee at the CDC creating recommendations for who should get the shots. Trump administration officials took the unusual step of announcing a policy change rather than seeking independent guidance from its own expert committees first.
Prassad joined the FDA after the longtime vaccine head Peter Marks quit, citing Kennedy's refusal to accept information that did not comport with his long-held opinions questioning vaccine safety.
According to the CDC, the LP.8.1 strain, a subvariant of the JN.1 strain, accounted for 70% of total cases in the US over a two-week period that ended on 10 May.
Covid-19 evolved less than in previous years, CDC microbiologist and immunologist Natalie Thornburg told the advisory committee. Most viruses currently circulating are descendants of the JN.1 virus variant, she said, though there is potential for that to be replaced. Wastewater in South Africa detected a new variant dubbed BA.3.2, which could indicate a shift in the virus. However, very few sequences of that variant have been identified globally.
Government experts presenting to the committee emphasized that Covid-19 was still causing a significant number of deaths in the US. Hospitalization rates have declined overall since 2021-2022 but are highest among people older than 65 and children younger than six months old.
Since October of last year, an estimated 30,000 to 50,000 people have died from the virus and between 260,000 and 430,000 have been hospitalized, according to data from the CDC.
'When you add up those cumulative rates over a 12-month period, Covid-19 is still causing an enormous burden on the US health system,' said Ruth Link-Gelles, an epidemiologist with the CDC.
Overall, almost all people in the US have experienced a Covid infection, meaning nearly everyone has some level of infection-induced immunity when vaccine efficacy was measured, but that immunity is believed to wane over time.
Vaccine-induced immunity, in this context, should be viewed as an 'added benefit', according to a CDC epidemiologist presenting to the committee.
Vaccine effectiveness could not be estimated for 2024-25 in children because of the low level of coverage and relatively low level of disease compared with earlier seasons. Last season had a lower overall rate of Covid hospitalization among children – though the youngest children notably had the worst hospitalization rates.