CVR - Coronavirus Vaccines R&D Roadmap

Milestone
2.2.a

Humoral immunity

In progress

Define the humoral mechanisms of protection at the mucosal barrier for coronavirus infection, disease, and transmission.

Progress Highlights

See CVR Scholar Hub page: Mucosal vs. Systemic Immunity to Coronaviruses

Mawer 2026 used a controlled human infection model study on 48 healthy adults that had previously been infected with SARS-CoV-2 and found that higher nasal IgG antibodies against the spike protein, particularly the RBD, were the strongest CoP against quantifiable viral shedding following controlled nasal inoculation with pre-alpha SARS-CoV-2.

BAFF and APRIL cytokines in mucosal tissues support the activation of B cells and the class switching to IgA production.

Chen 2025 found that Intranasal boosting can drive IgA class switching and maturation of memory B cell lineages primed by intramuscular vaccination.

Memory B cells, generated following vaccination or infection, are capable of rapid IgA production upon re-exposure.

Mucosal-associated invariant T cells (MAIT cells) activate dendritic cells via CD40L and priming Tfh cells, leading to more effective B cell activation.