SARS-CoV-2 genetic diversity: Its impact on vaccine efficacy

• Published in: Infectious diseases now (Online) Vol. 52; no. 8S; pp. S2 - S3
• Main Authors: Lina, B., Bauer, J.
• Format: Journal Article
• Language: English
• Published: France Elsevier Masson SAS 01.11.2022; Published by Elsevier Masson SAS
• Subjects: Antibodies, Viral; Covid; COVID-19 - epidemiology; COVID-19 - prevention & control; Genetic diversity; Genetic Variation; Humans; Neutralization Tests; Original; RNA, Messenger; RNA, Viral; SARS CoV 2; SARS-CoV-2 - genetics; Vaccine Efficacy; Variants; Covid; Variants; Genetic diversity; Vaccine efficacy; SARS CoV 2
• ISSN: 2666-9919; 2666-9919
• DOI: 10.1016/j.idnow.2022.09.008

•Variants in Covid are of major importance.•Omicron is significantly different from other variants.•Omicron presents reduced sensitivity to neutralizing antibodies.•A booster dose reduces the risk of severe clinical presentation. SARS CoV 2 S-glycoproteins play a crucial role in the entry steps of viral particles. Due to their surface location, they are the main target for host immune responses and the focus of most vaccine strategies. The D614G mutation identified in late January became dominant during March 2020, rendering SARS-CoV-2 more infectious. In April 2020, the Alpha, Beta and Gamma variants emerged simultaneously in Asia, South Africa, and South America, respectively. They were 1.6 to 2 times more transmissible than the ancestral strain. The currently dominant Omicron variant (BA.2) is not a direct descendant from the D614G lineage, but rather emerged from the BA.1 variant (as did BA.4 and BA.5). It is substantially different from all the other variants. It presents significantly reduced susceptibility to antibody neutralization: after 2 doses of mRNA-vaccine, neutralizing titers to Omicron are 41 to 84 times lower than neutralization titers to D614G. That said, a booster dose of mRNA-vaccine increases Omicron neutralization titers and reduces the risk of severe infection.