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Weakness of circulating SARS-CoV-2 variable to neutralization.

To the editor:

The emergence of two strains of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) – B.1.1.7 in the UK and B.1.351 in South Africa – raised concerns that these strains. May escape immunity resulting from previous Infection or vaccination In an attempt to measure the resistance of these strains to the neutralization arising from infection or vaccination, we created recombinant-covine viral stomatitis. 2 with a needle protein of the Wuhan-1 reference strain (wild type), a mutation of D614G, and variables B.1

.1.7 and B.1.351 (details on the recombination process are available in the appendix. Supplement, which is available along with the full text of this letter at NEJM.org).

Neutralization of SARS-CoV-2 Pseudoviruses In the sample of recovery serum and vaccine

Panel A shows 50% pseudovirus neutralization titer (pVNT50) In the recovery serum collected from 34 patients who had healed approximately 5 months after SARS-CoV-2 infection and in the serum collected from 50 vaccines administered BBIBP-CorV or CoronaVac 2. Up to 3 weeks after second dosing with recombinant vesicular stomatitis pseudovirus from SARS-CoV-2 with the Wuhan-1 inhibitory protein (wild type), the box plot indicates the median and interstitial c. Vartile (IQR); Tentacles represent 1.5 times the IQR, panel B shows the reciprocal serum pVNT changes.50 The titers in 34 recuperation serum samples were compared with strains D614G, B.1.1.7 and B.1.351 compared to the wild virus. C and D panels showed mutually change in pVNT.50 The titer in serum samples was obtained from 25 BBIBP-CorV vaccine recipients and 25 CoronaVac vaccine recipients, respectively, compared with strains D614G, B.1.1.7 and B.1.351 compared to the wild virus. Factor change in titer, geometric mean, and 95% confidence interval (CI) in pVNT.50 The titer, as opposed to the wild type virus, is shown under the P-value. Only P-values ​​are less than 0.05 (significant). Each data point is the mean of the duplicate test results. In each panel, the horizontal dash represents the lower limit of the test detection (titer, <30); This limit is assigned a value of 10 for the calculation of the geometric mean and is considered to be seronegativity. In all panels, calculations are performed using the Kruskal-Wallis dual-back test.

We will continue to assess pseudovirus resistance against neutralization using a recovery serum obtained from 34 patients 5 months after coronavirus disease 2019 (Covid-19) infection and serum from 50 participants. Receive 2 to 3 weeks after a second dose of a viral vaccine – BBIBP -CorV (Sinofarm).1 Or CoronaVac (Sinovac)2 – which was developed in China (Table S1 in the supplementary appendix), we first looked at serum antibody levels against wild pseudovirus strains and observed similar geometric mean (GMTs) in C. Serum obtained from the patient’s recovery and from the vaccine (Figure 1A), Which suggested a low antibody response after two vaccinations induced by BBIBP-CorV or CoronaVac.1,2 More specifically, the title neutralization was undetectable in 4 of 34 recuperative serum samples, in 6 of 25 BBIBP-CorV serum samples, and in 4 of 25 CoronaVac serum samples.

Next, we assess the neutralization activity of the recovery serum and inoculation serum against strains D614G, B.1.1.7 and B.1.351 compared to wild pseudoviruses. The recovery serum was significantly more effective (by Factor 2.4 95% Confidence Interval [CI], 1.9 to 3.0) in neutralizing D614G pseudovirus had similar effects to wild viruses in neutralizing B.1.1.7 and significantly less effective (by factor 0.5; 95% CI, 0.4 to 0.7). To neutralize B.1.351 pseudovirus (Figure 1BIn addition, 9 of the 30 recuperative serum samples lost their neutralization activity to B.1.351 completely for the BBIBP-CorV vaccine serum samples, although the GMT of the neutralization with The variables did not differ significantly from GMTs to wild viruses. But 20 serum samples showed total or partial loss of neutralization compared to B.1.351 (Figure 1CFor the CoronaVac Vaccinee serum sample, we found a significant decrease in GMTs in the serum neutralization of B.1.1.7 (by a factor of 0.5; 95% CI, 0.3 to 0.7) and B.1.351 ( By factor 0.3; 95% CI, 0.2 to 0.4) .In addition, most of the serum samples had a total or partial loss of neutralization compared to B.1.351 (Figure 1D).

Our results suggest that B.1.1.7 has little resistance to the neutralizing effect of the recovery serum or vaccine, while B.1.351 is resistant to the neutralization of both recovery serums (by a factor of 2). ) And the vaccine serum (by a factor of 2.5 to 3.3) than the wild type virus. Most vaccination serum samples were tested for hypersensitivity, the findings were consistent with other more recent studies on serum neutralization or serum neutrals obtained from Messenger RNA vaccine recipients; or BBIBP-CorV3-5 Our findings also highlight the importance of ongoing monitoring and evaluation of vaccines in virus-spread areas.

Guo-Lin Wang, Ph.D.
Beijing Institute of Microbiology and Epidemiology, Beijing, China

Zhuang-Ye Wang, B.Med.
Center for Disease Control and Prevention, Dezhou City, China

Li-Jun Duan, B.S.
Beijing Institute of Microbiology and Epidemiology, Beijing, China

Qing-Chuan Meng, B.Med.
Ningjin County Community Health Service Center, Dezhou, China

Ming-Dong Jiang, M. Med.
Jing Cao, M. Med.
Center for Disease Control and Prevention, Dezhou City, China

Lin Yao Bmed.
Ka-Li Zhu, B.Med.
Wu-Chun Cao, Ph.D.
New – Khma, MD.
Beijing Institute of Microbiology and Epidemiology, Beijing, China
[email protected], [email protected]

Supported by funding (L202038) from Beijing Natural Science Foundation And capital (81773494) from China Foundation for Natural ScienceBoth with Doctor Ma

The disclosure form provided by the author is available with the full text of this letter at NEJM.org.

This letter was published on April 6, 2021 at NEJM.org.

Dr.-L. Wang and Mr.Z.-Y. Wang equally support this letter.

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