Thread by @VintageKidsNL

Antibody landscapes after influenza virus infection or vaccination by Ron Foucier ncbi.nlm.nih.gov/pmc/articles/P…

Much of the global burden of infectious disease today is caused by antigenically variable pathogens, which escape immunity induced by prior infection or vaccination by changing the molecular structure recognized by #antibodies

Human influenza viruses are notorious for their capacity to evolve and evade the adaptive immune response.

As others have speculated, it is plausible that the decreased antibody responses to subsequent exposures may be a result of “antigen trapping”, a hypothesis according to which binding of antigen by pre-existing cross-reactive antibodies and memory-cells decreases the antigenic

antigen trapping”, a hypothesis according to which binding of antigen by pre-existing cross-reactive antibodies and memory-cells decreases the antigenic load available for priming naïve B-cells and leads to a diminished novel response

Note, when individuals have no prior immunity to a subtype, such as young children, or in a pandemic, the best vaccine is likely the closest antigenic match as there will be no prior immunity to avoid and no back-boost to exploit.

These findings highlight potentially important differences between the two types of vaccine mismatch in populations with prior immunity. Following a mismatch due to a delayed vaccine update

, neither pre-existing nor newly induced antibodies provide immunity against the novel strains.

Consequently, such vaccines have poor effectiveness in this mismatch situation (23-26).

@fitterhappierAJ