The Food and Drug Administration (FDA) has given instructions to Covid vaccine manufacturers regarding the target for next fall’s Covid vaccines. The FDA signaled that it prefers manufacturers to update the strain in their vaccine to a version of the virus that is currently circulating broadly, LP.8.1.
The statement from the FDA left the door open for Novavax, a company that requires months of lead time for vaccine production, to stick with an older version of the virus. During a meeting of the FDA’s expert vaccines panel, Novavax indicated its preference to stay with the older version.
The instructions were posted on the FDA’s website shortly after the meeting of the Vaccines and Related Biological Products Advisory Committee. The committee debated whether manufacturers should update their vaccines for the fall, with some members suggesting that manufacturers should have the option to update or stay with the same target.
The FDA advised manufacturers to target monovalent JN.1-lineage-based Covid-19 vaccines, preferentially using the LP.8.1 strain for the 2025-2026 season. The World Health Organization had previously recommended manufacturers to either stick with JN.1 or KP.2 strains of the virus or update to LP.8.1.
During the VRBPAC meeting, concerns were raised about potential delays in vaccine delivery if manufacturers were required to update the strain. Some committee members were not convinced that an update would offer significantly more protection. However, the committee unanimously voted to target a JN.1 version of the SARS-CoV-2 virus for the 2025-2026 vaccine.
The concerns raised by committee members were linked to a new Covid vaccine regulatory framework proposed by FDA Commissioner Marty Makary and Vinay Prasad. The framework suggests that Covid vaccines will only be available to high-risk individuals, such as those aged 65 or older or with underlying medical conditions.
Manufacturers may be required to conduct new randomized controlled trials in younger, healthy adults to determine the effectiveness of Covid vaccination. The framework also suggests that manufacturers may need to produce human immunogenicity data to support the approval of any updated product.
Moderna and the Pfizer-BioNTech partnership, which use messenger RNA technology for vaccine production, seemed prepared to move to the LP.8.1 strain. However, Novavax and its partner, Sanofi, expressed a preference for remaining with the JN.1 virus used in their previous vaccine.
The meeting of the Vaccines and Related Biological Products Advisory Committee marked the first time it had been allowed to convene since the start of the Trump administration. The committee was not consulted in March regarding the strains for next winter’s flu shot, and the FDA issued orders to flu vaccine manufacturers based on recommendations from a WHO-led meeting in February.
Overall, the FDA’s instructions to Covid vaccine manufacturers signal a potential shift in target strains for next fall’s vaccines, with some manufacturers facing challenges in meeting the new requirements. The debate over strain updates and the impact on vaccine delivery timelines will likely continue as manufacturers work to meet the FDA’s recommendations. Professor Monto, a respected figure in the field of public health at the University of Michigan, emphasized the importance of transparency in a recent meeting. He stressed the need for clear communication and openness in discussions surrounding Covid vaccines. However, not all participants shared his commitment to transparency. Prasad had already left the meeting, while Kaslow remained noncommittal, suggesting that the topic of transparency could be considered for a future VRBPAC meeting.
In a significant development, the FDA made an announcement regarding Pfizer and Moderna vaccines on Thursday. The regulatory body mandated that both companies include expanded warning labels on their products to alert consumers about the risk of myocarditis, a rare side effect characterized by inflammation of the heart muscle. This side effect, primarily observed in teenage boys, was also noted in individuals who had contracted Covid. During the initial phase of Covid vaccine distribution, cases of myocarditis were more commonly reported among individuals who had received two doses of the vaccine within a short interval of three to four weeks. However, recent data presented to the CDC’s expert panel revealed a significant decrease in myocarditis cases following Covid vaccination since 2021.
It is important to note a correction to an earlier version of this story, which inaccurately stated that the European Medicines Agency allowed vaccine manufacturers to choose which version of the Covid virus to target. This misinformation has been clarified to ensure accurate reporting on vaccine-related matters.
As the conversation around Covid vaccines continues to evolve, it is crucial for stakeholders to prioritize transparency, safety, and accurate information dissemination. By staying informed and engaging in open dialogue, we can navigate the complexities of vaccine distribution and ensure the health and well-being of the public.
