Study at KU Leuven on hamsters finds that immunity from XBB.1.5 COVID-19 vaccine favors the original strain, limiting antibody response to newer variants like JN.1.

Highlights the challenge of updating vaccines for evolving SARS-CoV-2.

While effective at preventing severe COVID-19, the protection you get from mRNA vaccines can fade within months.

Long-lasting immune cells that fight SARS-CoV-2 aren't usually found in mRNA-vaccinated people, unlike the immune cells for tetanus and flu.