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May 2022

Neutralizing antibodies against the SARS-CoV-2 Delta and Omicron variants following heterologous CoronaVac plus BNT162b2 booster vaccination.


Eddy Pérez-Then # 1Carolina Lucas # 2Valter Silva Monteiro # 3Marija Miric # 4Vivian Brache 5Leila Cochon 5Chantal B F Vogels 6Amyn A Malik 7 8Elena De la Cruz 5Aidelis Jorge 5Margarita De Los Santos 5Patricia Leon 9Mallery I Breban 6Kendall Billig 6Inci Yildirim 6 7 10Claire Pearson 11Randy Downing 11Emily Gagnon 11Anthony Muyombwe 11Jafar Razeq 11Melissa Campbell 10Albert I Ko 6 8 12Saad B Omer 6 7 8Nathan D Grubaugh 6 13Sten H Vermund 14Akiko Iwasaki 15 16.

PMID: 35051990 PMCID: PMC8938264 DOI: 10.1038/s41591-022-01705-6 Abstract Nat Med. 2022 Mar;28(3):481-485. doi: 10.1038/s41591-022-01705-6. Epub 2022 Jan 20


The recent emergence of the SARS-CoV-2 Omicron variant is raising concerns because of its increased transmissibility and its numerous spike mutations, which have the potential to evade neutralizing antibodies elicited by COVID-19 vaccines. Here we evaluated the effects of a heterologous BNT162b2 mRNA vaccine booster on the humoral immunity of participants who had received a two-dose regimen of CoronaVac, an inactivated vaccine used globally. We found that a heterologous CoronaVac prime vaccination of two doses followed by a BNT162b2 booster induces elevated virus-specific antibody levels and potent neutralization activity against the ancestral virus and the Delta variant, resembling the titers obtained after two doses of mRNA vaccines. Although neutralization of Omicron was undetectable in participants who had received a two-dose regimen of CoronaVac, the BNT162b2 booster resulted in a 1.4-fold increase in neutralization activity against Omicron compared with the two-dose mRNA vaccine. Despite this increase, neutralizing antibody titers were reduced by 7.1-fold and 3.6-fold for Omicron compared with the ancestral strain and the Delta variant, respectively. These findings have immediate implications for multiple countries that previously used a CoronaVac regimen and reinforce the idea that the Omicron variant is associated with immune escape from vaccines or infection-induced immunity, highlighting the global need for vaccine boosters to combat the impact of emerging variants.