key: cord-0709945-znq89zgv
authors: Huang, Baoying; Dai, Lianpan; Wang, Hui; Hu, Zhongyu; Yang, Xiaoming; Tan, Wenjie; Gao, George F
title: Serum sample neutralisation of BBIBP-CorV and ZF2001 vaccines to SARS-CoV-2 501Y.V2
date: 2021-04-13
journal: Lancet Microbe
DOI: 10.1016/s2666-5247(21)00082-3
sha: 759280ab984659ea365a193b0a90f6d1012fa517
doc_id: 709945
cord_uid: znq89zgv

nan

In the past few months, several SARS-CoV-2 variants of concern have been reported, especially the 501Y.V2, which was first isolated in South Africa, raising serious concern about the efficacy of the vaccines under development. 4 This variant was first isolated in China on Jan 25, 2021, 5 which contains ten amino acid mutation sites in spike (S) protein with five (Asp80Ala, Leu242del, Ala243del, Leu244del, and Arg246Ile) located at N-terminal domain, three (Lys417Asn, Glu484Lys, and Asn501Tyr) in RBD, and two in C-terminal domain 2 (CTD2) and S1/S2-S2' region (appendix p 2).

We assessed neutralisation activity in 24 serum samples from participants in two clinical trials, 12 who had been vaccinated with BBIBP-CorV and 12 who had been vaccinated with ZF2001, who were randomly selected to cover a range of different neutralising titres (appendix p 3). We measured the neutralising activity in these serum samples against live SARS-CoV-2 strains GDPCC (501Y.V2) 5 (appendix p 4). SARS-CoV-2 strains HB02 (wild type) and BJ01 (D614G) were tested as the control.

All 24 serum samples from either recipients of BBIBP-CorV or ZF2001 largely preserved neutralisation of the 501Y.V2 variant, with slightly reduced geometric mean titres (GMTs) compared with their titres against the wild type or D614G strains (appendix p 2). For BBIBP-CorV, the GMT decreased from 110·9 (95% CI 76·7-160·2) to 71·5 (51·1-100·1). For ZF2001, this the GMT decreased from 106·1 (95% CI 75·0-150·1) to 66·6 (51·0-86·9).

Our findings suggest that the 501Y.V2 variant does not escape the immunity induced by vaccines targeting the whole virus (BBIBP-CorV) or S protein dimeric RBD (ZF2001). The potential 1·5 to 1·6 times reduction in neutralising GMTs should be taken into account for their effect on the clinical efficacy of these vaccines. For both vaccines, immune serum samples neutralise both variant 501Y.V2 and D614G, the variant currently circulating globally, non-significantly (appendix p 2). For ZF2001, a some significance (p=0·04) between variant 501Y.V2 and the wild type might be due to the sample selection and size. The neutralisationreduction discrepancy between our protein-based vaccine against authentic virus and mRNA vaccine against pseudotyped virus needs further investigation in the future. 

Safety and immunogenicity of an inactivated SARS-CoV-2 vaccine, BBIBP-CorV: a randomised, doubleblind, placebo-controlled, phase 1/2 trial

A universal design of betacoronavirus vaccines against COVID-19, MERS, and SARS

Safety and immunogenicity of a recombinant tandem-repeat dimeric RBD-based protein subunit vaccine (ZF2001) against COVID-19 in adults: two randomised, double-blind, placebo-controlled, phase 1 and 2 trials

Serum neutralizing activity elicited by mRNA-1273 vaccine

Notes from the field: a case of new variant COVID-19 first emerging in South Africa detected in a security guard at the isolation point

See Online for appendix Lancet Microbe