Substantial Differences in SARS-CoV-2 Ab Responses Elicited by Natural Infection and mRNA Vaccine

[intrepidity]

6. Yes, thanks for pointing that out

We tend to think of "variants" as future/emerging, but that also includes known versions such as SARS-1 and MERS.

In addition to inducing increased Ab levels again SARS-CoV-2 RBD, the mRNA vaccine induced cross-reactive responses against SARS spike and SARS RBD. Conversely, natural exposure did not induce a cross-reactive response against the SARS spike and SARS RBD. The weak anti-RBD response induced by natural exposure may provide a mechanism for new variants to enter the population. This result can be interpreted based on immune selection pressure. Importantly, the mRNA vaccine induces a marked cross-reactive response against SARS spike, indicating that the mRNA vaccine adopts a conformation that presents cross-reactive epitopes to the immune system. This effect of the mRNA vaccine to induce cross-reactivity against diverse CoV strains is encouraging, providing further evidence that it may be effective against emerging virus variants.