key: cord-1045408-07eff4vi
authors: Shen, Xiaoying; Tang, Haili; Pajon, Rolando; Smith, Gale; Glenn, Gregory M.; Shi, Wei; Korber, Bette; Montefiori, David C.
title: Neutralization of SARS-CoV-2 Variants B.1.429 and B.1.351
date: 2021-04-07
journal: N Engl J Med
DOI: 10.1056/nejmc2103740
sha: 3b43eb03d30086e0fd41577cc30a53c339c56f46
doc_id: 1045408
cord_uid: 07eff4vi

nan

E484K, N501Y, and A701V). Neutralization assays were performed with the use of a validated lentivirus-based spike-pseudotyped virus assay in 293T cells that were stably transduced to overexpress angiotensin-converting enzyme 2. 4 The variant B.1.429 was neutralized by convalescent serum and by serum obtained from vaccinated persons, resulting in 50% inhibitory dilution (ID 50 ) geometric mean titers of 225 to 495 (Fig. 1A , and Table S1 in Supplementary Appendix 1, available with the full text of this letter at NEJM.org). The ID 50 and ID 80 titers against the B.1.429 variant for convalescent serum and for serum from persons who had received one of the vaccines were significantly lower than those against D614G (P<0.001) ( Fig. 1A and 1B, and Table S2 in Supplementary Appendix 2). The geometric mean ID 50 titers against B.1.429 were 3.1 times (range, 1.4 to 8.8) lower than those against D614G for convalescent serum and were 2.0 and 2.5 times (range, 0.7 and 8.6) lower than against D614G for serum from persons who had received the mRNA-1273 and NVX-CoV2373 vaccines, respectively ( Fig. 1C and Table S1 ). The geometric mean ID 50 titer against B.1.351 was 13.1 times lower than against D614G for convalescent serum and 9.7 times and 14.5 times lower than against D614G for serum from persons who had received the mRNA-1273 and NVX-CoV2373 vaccines, respectively (Fig. 1C ). Our findings regarding neutralization of the B.1.351 variant by serum obtained from recipients of the mRNA-1273 vaccine are consistent with those reported previously. 5 The modestly lower value in neutralization titers against the B.1.429 variant seen in this study is similar to that we saw previously when neutralization of the B.1.1.7 variant was tested with the same assay using serum samples obtained from recipients of the mRNA-1273 and NVX-CoV2373 vaccines. 4 These results, and the high efficacy shown by these vaccines, suggest that vaccineelicited neutralizing antibodies are likely to remain effective against the B.1.429 variant. The Thick black bars in Panel C represent the geometric mean titer differences for the sample sets, which are also labeled above each set. Circles in Panel C represent the differences in titers relative to D614G for individual samples. P values for the comparison of the reciprocal neutralization titers at 50% inhibitory dilution (ID 50 ) and 80% inhibitory dilution (ID 80 ) are pairwise comparisons of the data shown in Panels A and B, calculated with the use of the Wilcoxon signed-rank test. P values less than 0.001 correlate to Q (adjusted P) values less than 0.0019 (see Table S2 in Supplementary Appendix 2). Differences in the neutralization titers among the three sample sets shown in Panel C were not significant (P>0.05 by the Wilcoxon rank-sum test).

Emergence of a novel SARS-CoV-2 strain in southern California, USA

Safety and immunogenicity of SARS-CoV-2 mRNA-1273 vaccine in older adults

Phase 1-2 trial of a SARS-CoV-2 recombinant spike protein nanoparticle vaccine

SARS-CoV-2 variant B.1.1.7 is susceptible to neutralizing antibodies elicited by ancestral spike vaccines

Serum neutralizing activity elicited by mRNA-1273 vaccine

Correspondence Copyright © 2021 Massachusetts Medical Society

This letter was published on April 7, 2021, at NEJM.org.