FDA advisers urge targeting JN.1 strain in recipe for fall's COVID vaccines
How do the COVID-19 vaccines get updated annually, and what is the process involved in matching them to new virus strains?
The COVID-19 vaccines get updated annually to match newer strains of the virus through a process similar to how flu shots are updated each year. This involves evaluating the circulating strains of the virus, predicting which strains are likely to be dominant in the upcoming season, and then adjusting the vaccine composition accordingly.
The process begins with surveillance and research conducted by public health agencies and vaccine manufacturers to identify new variants of concern and monitor their spread. Scientists study the genetic sequences of these variants to understand how they differ from previous strains and how these changes might affect vaccine effectiveness.
Next, vaccine manufacturers develop candidate vaccines based on the selected strains and conduct clinical trials to evaluate their safety and efficacy. These trials usually involve several thousand participants and multiple study sites to ensure the vaccine works well and is safe for different populations.
Regulatory agencies, such as the U.S. Food and Drug Administration (FDA), review the data from these trials and decide whether to approve or authorize the updated vaccine for emergency use. The FDA considers factors such as the vaccine's safety profile, effectiveness against the targeted strains, and the ability to manufacture the vaccine at scale.
Once an updated vaccine is authorized, it is distributed to healthcare providers and administered to the public. Public health agencies, such as the Centers for Disease Control and Prevention (CDC), provide guidance on who should receive the updated vaccine and when, based on factors such as age, health status, and risk of exposure to the virus.
Finally, ongoing monitoring and evaluation of the updated vaccine's effectiveness and safety continue after its deployment. This helps inform future updates and ensures that the vaccine remains effective against emerging strains of the virus.
How did Dr. Peter Marks of the FDA liken the decision-making process for choosing the right variant to target in the vaccine update?
Dr. Peter Marks of the FDA likened the decision-making process for choosing the right variant to target in the vaccine update to picking the "freshest" milk with the longest expiration date in the grocery store. He emphasized the importance of making the best choice now, considering the potential evolution of the virus in the fall.
Why did the advisory panel prefer targeting the parent JN.1 variant over its offshoots for the next vaccine formulation?
The advisory panel preferred targeting the parent JN.1 variant over its offshoots for the next vaccine formulation because they believed that having a vaccine focused on the "trunk of the tree" rather than the "branches" would provide broader cross-protection against other subvariants that may emerge. They reasoned that choosing the parent JN.1 variant would offer some immunity against its descendant variants, making it a more effective choice for the upcoming vaccine. Additionally, the panelists acknowledged that predicting which specific offshoot would become the most prominent threat in the future was challenging, so focusing on the parent variant was a more logical approach.