Mucosal and Serum Antibodies 3 Weeks after Symptomatic BA.2.86 Infection

This correspondence describes immune responses following a confirmed symptomatic BA.2.86 infection in an immunocompetent woman in Sweden. Despite prior vaccination and infection, she contracted BA.2.86 during community screening. Three weeks post-infection, serum and mucosal samples showed markedly boosted antibodies, including a 36-fold increase in serum nucleocapsid IgG and elevated mucosal IgA responses to wild-type and BA.5 spike proteins. These findings suggest that BA.2.86 can evade pre-existing immunity and significantly enhance mucosal and systemic antibody levels. The results underscore the need for updated vaccine monitoring and preparedness for emerging subvariants.

This correspondence describes immune responses following a confirmed symptomatic BA.2.86 infection in an immunocompetent woman in Sweden. Despite prior vaccination and infection, she contracted BA.2.86 during community screening. Three weeks post-infection, serum and mucosal samples showed markedly boosted antibodies, including a 36-fold increase in serum nucleocapsid IgG and elevated mucosal IgA responses to wild-type and BA.5 spike proteins. These findings suggest that BA.2.86 can evade pre-existing immunity and significantly enhance mucosal and systemic antibody levels. The results underscore the need for updated vaccine monitoring and preparedness for emerging subvariants.