First identified in New York City in November 2020, the B.1.526 variant saw its prevalence increase sharply since the start of the year. The proportion of this new viral lineage thus increased from 3% in mid-January 2021 to 34% at the end of February. As of April 5, 2021, the analysis by two large laboratories of a representative sample of New York patients with Covid-19 revealed that 40% of all viruses sequenced corresponded to B.1.526 variants.
There are two subpopulations within the B.1.526 lineage, depending on whether the virus contains the E484K mutation or not. About half of the B.1.526 variants carry this mutation, which is known to be associated in vitro with a decrease in the neutralization of antibodies and therefore with a possible immune escape. This E484K mutation is also found in the variants of concern identified in South Africa (B.1.351) and in Brazil (P.1). This New York variant contains a second worrying mutation, N501Y*. Associated with increased transmissibility, it is present in the English B.1.1.7, South African B.1.351 and Brazilian P.1 variants.
New York variants which do not contain the E484K mutation contain the S477N mutation which has no impact on the neutralization capacity of antibodies. These B.1.526-S477N viruses therefore constitute a distinct sublineage within the B.1.526 variants.
The public health department has received samples from residents of New York City. Characteristics demographic and clinical people infected with the New Yorker B1.526 and English B.1.1.7 variants were compared.
Epidemiologists from the New York City Department of Health and Mental Hygiene also sought to determine whether or not the New York variant was responsible for re-infections or even infections occurring in people who have been partially or fully vaccinated. It will be recalled that, by definition, reinfection corresponds to contamination by SARS-CoV-2, confirmed by genomic sequencing, occurring after a period of at least 90 days after a last positive PCR or antigen test. An infection is qualified as post-vaccination when an individual is found positive in a PCR or antigen test carried out on a respiratory sample taken at least 14 days after the injection of the second dose of vaccine.
The study by New York epidemiologists, published May 5, 2021 in the weekly bulletin of the Centers for Disease Control and Prevention (CDC), reveals that 56% of B.1.526 variants contain the E484K mutation.
On April 5, the B.1.526 variants carrying the E484K mutation represented 25% of all SARS-CoV-2 viruses sequenced, against 16% for the B.1.526 variants not carrying the E484K mutation. As for the proportion of the English variant B.1.1.7, it has recently increased, reaching today 36% of the samples analyzed.
The 3,679 patients infected with the New York variant were between 23 and 50 years old (median age: 35). Compared to patients whose infection was not associated with a “variant of concern” or a “variant of interest”, those infected with variant B.1.526 preferentially lived in the Bronx or in neighborhoods with a high rate of poverty. or very high, or belonged to the black community.
Of the patients infected with the B.1.526 variant, approximately 71% were symptomatic, 4% were hospitalized, and 0.5% died. These different rates do not differ from those observed in the population of patients who were not infected with variants of concern or of interest. In contrast, the hospitalization rate among patients infected with the English variant B.1.1.7 was higher (5.8%).
A variant not associated with more severe disease
These preliminary results indicate, however, that the B.1.526 variant does not cause more severe Covid-19 disease. In addition, the rate of reinfection, among patients infected with the B.1.526 virus carrying the E484K mutation, is generally low, of the order of 0.5%. There is a lack of hindsight to estimate the possible risk of contamination by this variant B.1.526–E484K in vaccinated people. Indeed, the population in which the highest prevalence of infection with the B.1.526 virus is observed is that which is the least vaccinated, which limits the possibility of evaluating the occurrence of post-vaccination infections.
Another study, conducted by researchers at Columbia University in New York and published on April 15, 2021 as a preprint on the site medRxiv, indicates that the variant B.1.526–E484K is partially or completely resistant to two monoclonal antibodies used in therapy. It is also four times less sensitive to neutralization by antibodies present in the plasma of convalescent Covid-19 patients and about 3.5 times less sensitive to serum antibodies induced by vaccination.
To date, the Lineage B.1.526 has circulated throughout the United States as well as 21 countries including Aruba (Netherlands Antilles), Ecuador, Puerto Rico, St. Martin.
Marc Gozlan (Follow me on Twitter, Facebook, LinkedIn)
* The E484K and S477N mutations are located within the protein spike, in the receptor binding domain (RBD) with the ACE2 cellular receptor. Three mutations, responsible for amino acid changes, are characteristic of the B.1.526 line: L5F, T95I, D253G. Sublines have additional modifications: S477N, E484K, A701V and Q957R.
To know more :
Thompson CN, Hughes S, Ngai S, et al. Rapid Emergence and Epidemiologic Characteristics of the SARS-CoV-2 B.1.526 Variant — New York City, New York, January 1–April 5, 2021. MMWR Morb Mortal Wkly Rep. ePub: 5 May 2021. doi: 10.15585/mmwr.mm7019e1
Annavajhala MK, Mohri H, Wang P, et al. A Novel and Expanding SARS-CoV-2 Variant, B.1.526, Identified in New York. medRxiv. Posted April 15, 2021. doi: 10.1101/2021.02.23.21252259
Lasek-Nesselquist E, Lapierre P, Schneider E, et al. The localized rise of a B.1.526 SARS-CoV-2 variant containing an E484K mutation in New York State. medRxiv. Posted online March 1, 2021]. doi: 0.1101/2021.02.26.21251868
Annavajhala MK, Mohri H, Zucker JE, et al. A novel SARS-CoV-2 variant of concern, B.1.526, identified in New York. medRxiv. Posted online February 25, 2021. doi: 10.1101/2021.02.23.21252259
West AP, Barnes CO, Yang Z, Bjorkman PJ. SARS-CoV-2 lineage B.1.526 emerging in the New York region detected by software utility created to query the spike mutation landscape. bioRxiv. Posted online February 23, 2021. doi: 10.1101/2021.02.14.431043
On the Web :
B.1.526 Lineage with S:E484K Report (Outbreak.info)
–
