Barouch et al.: "Neutralization Escape by SARS-CoV-2 Omicron Subvariants BA.2.12.1, BA.4, & BA.5"; shows that the BA.2.12.1, BA.4, & BA.5 variants escape neutralizing antibodies VAX & natural exposure

Yet the key message here is natural infection, natural immunity shows much greater neutralizing antibody response than in those vaccinated with Pfizer jab, even to legacy WA1/2020 isolate

The key is that the neutralizing antibody response in persons with natural infection was far greater than in the vaccinated (vaccinal response). I would say crudely, two times greater. Again, natural exposure immunity is superior. See chart below of neutralizing antibody titers based on vaccination (before boost vs after boost) versus prior infection (B and C). See even after boosting, antibody levels still lower and the fact is that based on original antigenic sin, the imprinting and initial priming to the initial exposure e.g. Wuhan legacy strain, makes subsequent immune responding weaker with emerging more infectious subvariants. Remember, natural exposure immunity is to the full entire viral ball and all proteins etc. on the viral surface and internal nucleocapsid conserved proteins etc. Not just the spike antigen target as with vaccinal immunity.

“Six months after the initial two BNT162b2 immunizations, the median neutralizing antibody pseudovirus titer was 124 against WA1/2020 but less than 20 against all the tested omicron subvariants (Figure 1B). Two weeks after administration of the booster dose, the median neutralizing antibody titer increased substantially, to 5783 against the WA1/2020 isolate, 900 against the BA.1 subvariant, 829 against the BA.2 subvariant, 410 against the BA.2.12.1 subvariant, and 275 against the BA.4 or BA.5 subvariant.

Among the participants with a history of Covid-19, the median neutralizing antibody titer was 11,050 against the WA1/2020 isolate, 1740 against the BA.1 subvariant, 1910 against the BA.2 subvariant, 1150 against the BA.2.12.1 subvariant, and 590 against the BA.4 or BA.5 subvariant.”

“These data show that the BA.2.12.1, BA.4, and BA.5 subvariants substantially escape neutralizing antibodies induced by both vaccination and infection. Moreover, neutralizing antibody titers against the BA.4 or BA.5 subvariant and (to a lesser extent) against the BA.2.12.1 subvariant were lower than titers against the BA.1 and BA.2 subvariants, which suggests that the SARS-CoV-2 omicron variant has continued to evolve with increasing neutralization escape. These findings provide immunologic context for the current surges caused by the BA.2.12.1, BA.4, and BA.5 subvariants in populations with high frequencies of vaccination and BA.1 or BA.2 infection.”