Neutralization profile of Omicron variant convalescent individuals

Abstract

Recently, the Omicron variant of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been described as immune escape variant.Here, we analyzed samples from BA.1 (Omicron) convalescent patients with different constellations of prior SARS-CoV-2 immunity regarding vaccination and previous infection with a non-Omicron variant and determined titers of neutralizing antibodies against different SARS-CoV-2 variants (D614G, Alpha, Beta, Delta, Gamma, Omicron).We found high neutralizing antibody titers against all variants for vaccinated individuals after BA.1 breakthrough infection or for individuals after infection with a pre-omicron variant followed by BA.1 infection. In contrast, samples from naive unvaccinated individuals after BA.1 infection mainly contained neutralizing antibodies against BA.1 but only occasionally against the other variants.

Boosting with Omicron-matched or historical mRNA vaccines increases neutralizing antibody responses and protection against B.1.1.529 infection in mice

“…However, neutralizing antibody titers against heterologous WA1/2020 D614G, B.1.351, and B.1.617.2 strains were much lower, as reported by another group (Lee et al, 2022) and also described in unvaccinated humans that experienced a primary B.1.1.529 infection (Rössler et al, 2022) . Thus, in unvaccinated, uninfected individuals, bivalent or multivalent mRNA vaccines (Pajon et al, 2022;Ying et al, 2021) (e.g., mRNA-1273+ mRNA-1273) might be required to achieve necessary breadth of humoral responses.…”

mRNA-1273 or mRNA-Omicron boost in vaccinated macaques elicits comparable B cell expansion, neutralizing antibodies and protection against Omicron

“…Importantly, it would need to be established that a switch in COVID-19 vaccine design to match the current dominant variant would not jeopardize responses against variants which may be antigenically distant from Omicron but close to the prototype. Indeed a recent study has shown that immunization of mice with an Omicron mRNA vaccine elicited strong neutralization against Omicron but not to other variants, consistent with data from primary Omicron infection (Lee et al, 2022; Roessler et al, 2022; Suryawanshi et al, 2022). Thus, a combination or bivalent vaccine to generate B cells specific for the current variant as well as cross-reactive to other variants might ensure greater breadth of neutralization.…”

Extensive neutralization against SARS-CoV-2 variants elicited by Omicron-specific subunit vaccine booster

“…Recent research reported the consistent result that vaccination followed by breakthrough Omicron infection improved cross-neutralization of VOCs 12,13 , while neutralizing capacity of the unvaccinated individuals, which is triggered by Omicron, do not cross-neutralize other variants.…”

“…Compared to the previous infection with the ancestral strain WT, NAb titers against several variants from individuals infected with Delta or Omicron after breaking through the early immune protection generated by vaccines is significantly higher and wider. Recent research reported the consistent result that vaccination followed by breakthrough Omicron infection improved cross-neutralization of VOCs 12,13 , while neutralizing capacity of the unvaccinated individuals, which is triggered by Omicron, do not cross-neutralize other variants.…”