| Literature DB >> 35051989 |
Samuel M S Cheng1, Chris Ka Pun Mok2,3, Yonna W Y Leung1, Susanna S Ng4, Karl C K Chan1, Fanny W Ko4, Chunke Chen2,3, Karen Yiu4, Bosco H S Lam5, Eric H Y Lau1,6, Ken K P Chan4, Leo L H Luk1, John K C Li1, Leo C H Tsang1, Leo L M Poon1,7, David S C Hui8,9, Malik Peiris10,11.
Abstract
The Omicron variant is rapidly becoming the dominant SARS-CoV-2 virus circulating globally. It is important to define reductions in virus neutralizing activity in the serum of convalescent or vaccinated individuals to understand potential loss of protection against infection by Omicron. We previously established that a 50% plaque reduction neutralization antibody titer (PRNT50) ≥25.6 in our live virus assay corresponded to the threshold for 50% protection from infection against wild-type (WT) SARS-CoV-2. Here we show markedly reduced serum antibody titers against the Omicron variant (geometric mean titer (GMT) < 10) compared to WT virus 3-5 weeks after two doses of BNT162b2 (GMT = 218.8) or CoronaVac vaccine (GMT = 32.5). A BNT162b2 booster dose elicited Omicron PRNT50 titers ≥25.6 in 88% of individuals (22 of 25) who previously received 2 doses of BNT162b2 and 80% of individuals (24 of 30) who previously received CoronaVac. However, few (3%) previously infected individuals (1 of 30) or those vaccinated with three doses of CoronaVac (1 of 30) met this threshold. Our findings suggest that countries primarily using CoronaVac vaccines should consider messenger RNA vaccine boosters in response to the spread of Omicron. Studies evaluating the effectiveness of different vaccines against the Omicron variant are urgently needed.Entities:
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Year: 2022 PMID： 35051989 PMCID： PMC8940714 DOI： 10.1038/s41591-022-01704-7
Source DB: PubMed Journal: Nat Med ISSN： 1078-8956 Impact factor: 87.241