FDA Approves Novavax COVID Vaccine After Pfizer and Moderna

On Friday, the Food and Drug Administration (FDA) granted approval for an updated COVID-19 vaccine developed by Novavax, following the previous week’s endorsement of new vaccines from Pfizer and Moderna. This decision comes as the fall and winter seasons approach, a period traditionally marked by a surge in respiratory illnesses. The Novavax vaccine specifically targets the JN.1 COVID-19 variant, which was once the dominant strain in the United States but now accounts for less than 1% of current cases. In contrast, the vaccines from Pfizer and Moderna are designed to address the KP.2 variant, which is a descendant of JN.1.

Initially, the FDA had instructed vaccine manufacturers to develop vaccines targeting the JN.1 variant. However, as new data became available, the agency revised its recommendation to focus on the KP.2 variant. This shift in guidance was based on updated case information and the evolving landscape of COVID-19 variants. Novavax, which had already been in the process of producing vaccines for the JN.1 variant, announced its ability to quickly adapt its production to also address the KP.2 strain. As a result, Novavax has indicated that its updated vaccines will be made available at numerous locations once the FDA’s Center for Biologics Evaluation and Research releases the vaccine batches.

Moderna has projected that its updated vaccine will be accessible “within the coming days,” while Pfizer has stated that its vaccine “will begin shipping immediately” and will soon be available in pharmacies, hospitals, and clinics across the United States. The FDA’s accelerated use authorization for the updated vaccines from Moderna and Pfizer was granted on August 22. This approval was aimed at providing more targeted protection against currently circulating COVID-19 variants and enhancing defense against severe outcomes associated with the virus.

The newly approved vaccines are classified as monovalent, meaning they are designed to target a specific COVID-19 variant. Despite this, they still offer some level of protection against other strains. The KP.2 variant, targeted by both Pfizer and Moderna’s vaccines, is a descendant of the JN.1 variant, which itself originated from the omicron lineage. While KP.2 was the dominant strain earlier in the summer, it has recently been surpassed by its descendants in terms of prevalence.

Clinical trials have demonstrated that the updated vaccines offer improved protection against the JN lineage compared to the previously available XBB vaccines. For instance, Pfizer’s KP.2 vaccine showed up to a 7.3-fold stronger immune response in mice infected with KP.2 and other JN variants, compared to its XBB vaccine. Similarly, Moderna’s KP.2 vaccine was found to be up to eight times more effective in protecting mice against JN variants than its XBB.1.5 vaccine. Novavax’s research highlighted that its JN.1 vaccine, administered to mice following an initial XBB.1.5 vaccine, was up to 48 times more effective in protecting against the JN lineage than the initial XBB.1.5 shot.

The Centers for Disease Control and Prevention (CDC) has recommended that everyone aged six months and older receive an updated COVID-19 vaccine, irrespective of their previous vaccination status. Both Moderna and Pfizer’s vaccines will be available for individuals aged six months and older, while Novavax’s vaccine will be targeted at those aged 12 and older. As the respiratory virus season approaches, the availability of these updated vaccines is expected to play a critical role in mitigating the impact of COVID-19 and other respiratory illnesses, underscoring their importance in public health efforts.