| Autor: |
Nancy H. L. Leung, Samuel M. S. Cheng, Mario Martín-Sánchez, Niki Y. M. Au, Yvonne Y. Ng, Leo L. H. Luk, Karl C. K. Chan, John K. C. Li, Yonna W. Y. Leung, Leo C. H. Tsang, Sara Chaothai, Kelvin K. H. Kwan, Dennis K. M. Ip, Leo L. M. Poon, Gabriel M. Leung, J. S. Malik Peiris, Benjamin J. Cowling |
| Rok vydání: |
2022 |
| Popis: |
BackgroundLimited data exist on antibody responses to mixed vaccination strategies involving inactivated COVID-19 vaccines, particularly in the context of emerging variants.MethodsWe conducted an open label trial of a third vaccine dose of an mRNA vaccine (BNT162b2, Fosun Pharma/BioNTech) in adults aged ≥30 years who had previously received two doses of inactivated COVID-19 vaccine. We collected blood samples before administering the third dose and 28 days later, and tested for antibodies to the ancestral virus using a binding assay (ELISA), a surrogate virus neutralization test (sVNT) and a live virus plaque reduction neutralization test (PRNT). We also tested for antibodies against the Omicron variant using live-virus PRNT.ResultsIn 315 participants, a third dose of BNT162b2 substantially increased antibody titers on each assay. Mean ELISA levels increased from an optical density (OD) of 0.3 to 2.2 (p50 titers rose very substantially by at least 24 fold from Day 0 to Day 28 against the ancestral virus (pConclusionsA third dose of COVID-19 vaccination with an mRNA vaccine substantially improved antibody levels against the ancestral virus and the Omicron variant with well-tolerated safety profile, in adults who had received two doses of inactivated vaccine 6 months earlier.SummaryIn this open label trial of Chinese adults aged ≥30 years who received two doses of inactivated COVID-19 vaccine 6 months earlier, third-dose mRNA vaccine substantially improved antibody levels against the ancestral virus and Omicron variant with well-tolerated safety profile. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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