Vaccination-induced responses to the neutralizing variable omicron


In a recent study published in medRxiv* Prepress server, researchers summarize existing data on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sub variant of the Omicron (BA.1, BA.1.1, BA.2, BA.2.12.1, BA. 3, and BA.4/5) neutralization. They also performed a comparative evaluation of the cross-neutralization responses of the Omicron sub-variables compared to the Wuhan-Hu-1 strain (prototype) antigen.

Study: Post-vaccination neutralization responses to omicron subvariables.  Image Credit: Naeblys / Shutterstock
Stady: Post-vaccination neutralization responses to omicron sub-variables. Image Credit: Naeblys / Shutterstock

The continued development of Omicron and the consequent emergence of sub-variants with higher susceptibility to infection and immune evasion has threatened vaccination. effectiveness With a decrease in vaccination-induced cross-neutralization responses. In vitro studies reported significantly decreased AB (antibody) function against the Omicron spike (S) protein between vaccinated and vaccinated subjects with a previous history of non-Omicron infection.

about studying

In this study, researchers evaluated the responses of nulling variants caused by coronavirus 2019 (COVID-19) vaccines.

Databases such as PubMed, medRxiv and bioRxiv were searched between November 26, 2021 and July 25, 2022, for studies evaluating post-COVID-19 vaccination responses that neutralize Ab (nAb) responses to Omicron subvariants. The study was secondary to a literature review. It included only published studies or prior publications evaluating nAb responses to the ≥1 Omicron subvariant induced by the WHO-approved COVID-19 vaccine. It also analyzed samples obtained less than 6 months after the last vaccination.

Data were obtained for the neutralization assay, reference SARS-CoV-2 strain, sample size, vaccination doses, type of vaccination, duration between most recent vaccination and sample collection, nAb titers for the Wuhan-Hu-1 strain, Omicron subvariables and sample lineage with a resizable nAb titer. For discovery or prototyping strain and each sub-variable.

Studies were excluded if alternative equivalence assays were used, immunosuppressed individuals were sampled, and previously selected low or high responding study groups formed. Studies of more than 20% of individuals with hybrid immunity (natural infection and immunization) were also excluded. The mean fold decrease in the Omicron subvariant nAb titer compared to each other and the Wuhan-Hu-1 strain was evaluated, and the effector ratios were averaged in terms of stress.

consequences

In total, abstracts from 6318 studies were examined, of which only 213 studies were eligible for full-text review, of which 153 were considered for final analysis. About 80% (n = 122 studies) studies assessed fold reductions for Omicron subvariants with respect to the Wuhan-Hu-1 strain, 22% (n = 33) studies assessed fold reductions for other Omicron subvariants related to Omicron BA.1, and 88% (n = 135) provided data on the percentage of responses to the ≥1 Omicron subvariant.

Among the included studies, post-primary vaccination for COVID-19, variable-wise reductions in nAb titers with respect to the Wuhan-Hu-1 strain showed wide differences, from 4.2-fold for Omicron BA.3 to 22-fold for Omicron BA.4/ 5. Among the reinforced individuals, fold reductions were comparable for all Omicron subvariants (between sixfold and sevenfold), except for the Omicron BA.4/5 subvariant (13fold).

The induced nAb titers after the primary and booster vaccinations were similar for all Omicron subvariants, except for BA.4/5 where the fold reductions were higher (two-fold higher) with respect to Omicron BA.1. The percentages of Omicron-type responders were lower after the initial COVID-19 vaccination (between 34% and 57%) compared to the Wuhan-Hu-1 strain (96%). However, it increased after booster vaccinations (between 85% and 93%).

Of the included studies, 82% (n = 125 studies) provided data on fold reductions of the 1 Omicron variant in relation to the Wuhan-Hu-1 strain. Post-primary COVID-19 vaccines, fold reductions with respect to the Wuhan-Hu-1 strain were significant for all Omicron subvariants, ranging from 4.2-fold for Omicron BA.3 to 22-fold for Omicron BA.4/BA.5 subvariants and observed across all Vaccine platforms, with the largest decrease (42.5-fold) by protein-based COVID-19 vaccines.

The fold reductions against Omicron BA.1 with respect to the Wuhan-Hu-1 strain were higher (21-fold) higher (21-fold) for the COVID-19 messenger ribonucleic acid (mRNA) vaccines than with the vector-based (12-fold) and inactivated (11-fold) COVID-19 vaccines. Moreover, folded reductions of heterogeneous vaccination strategies for COVID-19 that include mRNA vaccines were significant (22-fold).

Subsequent vaccinations, incorrect caliber The fold reductions of the Omicron sub-variables with respect to the Wuhan-Hu-1 prototype were not as prominent as those observed after initial vaccinations and ranged from six-fold for Omicron BA.2 to 13-fold for Omicron BA.4/5. The average fold decrease was nAb eightfold, ninefold, tenfold, and sixfold relative to Omicron BA.1 by vector-based, inactivated and protein-based vaccines compared to mRNA vaccines; However, the results were heterogeneous.

Overall, the study results showed that reductions in nAb titer for Omicron subvariants with respect to the Wuhan-Hu-1 strain varied significantly after initial COVID-19 vaccinations but were similar after booster vaccinations, with the exception of Omicron BA.4/5, for That cuts were fold higher. The results showed that vaccine efficacy is likely to be lower for omicron subvariants, especially for BA.4/5.

*Important note

medRxiv publishes preliminary scientific reports that are not subject to peer review, and therefore should not be considered conclusive, guide clinical practice/health-related behavior, or be treated as established information.



Source link

Related Posts

Precaliga