Serum from the blood of people vaccinated with Sputnik V, like that of those who had coronavirus in 2020, contains neutralizing antibodies against the variants Gamma that originated in Manaos, Alpha first detected in UK Y Lambda (Andina), which have community circulation in the Argentinaaccording to a recent study by local scientists.
The work was carried out by researchers from the PAIS project (Argentine Interinstitutional Project of Genomics of SARS-CoV-2), the Biobank of Infectious Diseases BBEI, the Inbris Institute and the Hospital de Clínicas José de San Martín.
The objective was to evaluate “the neutralizing capacity of sera obtained from individuals infected by SARS-CoV-2 during the year 2020 and of individuals vaccinated with Sputnik V, compared to the variants of SARS-CoV-2 currently circulating in Argentina: lineages P.1 (Gamma, Manaos), B.1.1.7 (Alpha, UK) y C.37 (Lambda, Andina)”.
To make the comparison, the researchers took as a reference “the neutralizing activity exerted by the sera against the B.1 lineage (reference strain of the year 2020)”.
“What was observed is that both with one dose and with two the sera of people immunized with Sputnik V maintained the level of neutralizing antibodies against Alpha Y Lambda same as against the 2020 reference strain; the same thing happened with convalescent sera “, explained the virologist and member of the Country Project Humberto Debat.
In the case of Gamma variant, the researcher detailed that “neutralizing antibodies decrease three times in relation to the response against the reference strain that was used in 2020, which, although significant, is not dramatic.”
The specialist recalled that “these in vitro tests only reflect the humoral response (antibodies) but not the cellular one (mediated by the lymphocytes that provide memory), so they do not express the total response of the immune system and a decrease in antibodies do not necessarily imply a decrease in protection. “
The data obtained by this work in relation to the decrease in the neutralization capacity of the sera of convalescent and vaccinated with Sputnik V versus variant Gamma are consistent with other studies conducted abroad with Pfizer vaccines and Oxford/Aztrazeneca.
One of the most important contributions of this study is that it reports for the first time that the variant Lambda (incorporated by the WHO as a variant of interest) is “efficiently neutralized by the antibodies generated in response both to infection by circulating variants in our country in 2020, as well as by those generated in response to vaccination with Sputnik V.”
The report recalled that since March of this year “a change in the circulation dynamics of viral variants of SARS-CoV-2 in Argentina it has raised a new alarm in the field of public health. “
Since then, thanks to the surveillance of SARS-CoV-2 variants carried out by the PAIS Project and the ANLIS-Malbrán, four variants were detected in individuals without a history of traveling abroad or close contact with travelers: two considered of concern for the OMS, the Alpha variant (B.1.1.7 lineage, UK) and the Gamma (P.1 lineage, Manaus); and two defined as “of interest”, the Zeta variant (lineage P.2, Rio de Janeiro) and the Epsilon variant (lineages B.1.427 and B.1.429, California).
In addition, a sustained increase in the frequency of the C.37 lineage (Andean variant) was detected, recently included by the World Health Organization (WHO) as a variant of interest, called Lambda.
At present, more than 95% of the SARS-CoV-2 viruses that circulate in the Metropolitan Area of Buenos Aires (AMBA) correspond to the variants of international concern Gamma and Alpha, and to the variant of interest Lambda.
The WHO defined as a variant of concern those in which it has been shown, after a comparative evaluation, that they are associated with an increase in transmissibility, an increase in virulence or a change in the clinical presentation of the disease; or decrease in the effectiveness of social and public health measures or of the means of diagnosis, vaccines and available treatments.
While the variants of interest are those that in their genome have mutations with established or presumed phenotypic implications or have been identified as a cause of community transmission or multiple cases / groups of Covid-19, or have been detected in multiple countries.