Booster vaccination strengthens existing defenses against newer COVID-19 variants

Booster vaccination strengthens existing defenses against newer COVID-19 variants

The SARS-CoV-2 genome is subject to constant mutations. Some of these mutations reduce the effectiveness of RNA-based vaccines, which consequently have to be adapted regularly. Until now, however, it was unclear how the immune system reacts to new virus variants. Are mainly pre-existing memory B cells reactivated, or are new naive B cells also activated on a larger scale? This question is particularly relevant for people whose immune response has already been shaped by previous vaccinations and infections.