New findings may explain why mRNA vaccines provide limited protection against omicron

Vaccination protects against severe COVID-19 but not against infection. Researchers at Karolinska Institutet and Danderyd Hospital now show that protection against infection with the new omicron variants is linked to mucosal IgA antibodies, which are not induced by vaccination. These are the findings of two studies recently published in The Lancet Infectious Diseases, and The Lancet Microbe, and could explain the limited protection by currently available vaccines against infection.