What are the specific changes in the new 2024-2025 covid-19 vaccines aimed at reducing hospitalizations and deaths? 
- JN.1 lineage: The WHO announced in April 2024 that their COVID vaccine advisory group advises using the JN.1 lineage as the antigen for the upcoming formulations of the vaccine. All FLiRT variants are within the JN.1 family of variants.
- KP.2 and KP.3 strains: Moderna’s KP.2 vaccine was up to eight times more effective at protecting mice against JN variants than its XBB.1.5 vaccine. Pfizer’s KP.3 COVID-19 vaccine offered up to a 7.3-times stronger response to mice infected with KP.3 and several other JN variants, according to trial data.
- Monovalent vaccines: The new vaccines are monovalent, targeting a single strain (JN.1 lineage) rather than a combination of strains, as seen in previous vaccines.
- Updated formula: The vaccines have undergone an updated formula to better protect against severe COVID-19–associated illness and death, particularly among older adults and those with compromised immune systems.
- Boosted protection: The updated vaccines aim to restore and enhance protection against the virus variants currently responsible for most infections and hospitalizations in the United States, reducing the risk of severe outcomes, including hospitalization and death.
- Long COVID prevention: The vaccines are designed to reduce the risk of Long COVID, a condition that can develop during or following acute infection and last for an extended duration.
These changes are intended to improve the effectiveness of the vaccines in reducing hospitalizations and deaths, particularly among vulnerable populations.
