03/04/2021 13:20
Clarín.com
Society
Updated 03/04/2021 1:34 PM
A study, led by CONICET researchers and carried out under the coordination of the Ministry of Health of the Province of Buenos Aires, found that people previously infected with coronavirus may
not require the second dose
of the Russian
Sputnik V
vaccine
.
The research, in which hundreds of volunteers who are part of the health personnel of the public subsector participated, determined that
100% of the people who participated in the study developed specific antibodies
against Covid-19 after receiving the complete scheme of two doses of the Russian vaccine and suggests
reviewing the vaccination schedule
for those individuals who were previously infected with this virus.
"The results of the study show that people previously exposed to the virus, who were shown to have antibodies before the start of vaccination, generate
a rapid humoral immune response when receiving a dose
of the Sputnik vaccine, producing levels of
antibodies similar or even higher than those produced by uninfected people
who received two doses of the vaccine, "said Andrea Gamarnik, head of the Molecular Virology Laboratory of the Fundación Instituto Leloir (FIL), senior researcher at CONICET and a member of the study team.
For his part, Jorge Geffne -conicet senior researcher and member of the team that carried out the study- specified that the results "suggest that
the previous infection generates immunological memory that is evidenced with the first dose
of Sputnik V producing increased levels of antibodies in comparison with previously uninfected individuals ".
The finding would support a review of the vaccination schedule for those with a confirmed history of coronavirus infection, which would allow optimizing resources without compromising the effectiveness of immunization.
In the first stage of the study
, the immune response of 142 health workers, between 18 and 59 years old
, who volunteered, belonging to seven public centers in the Province, of which 22 had been previously infected,
was analyzed
.
Study details
The approved Sputnik V vaccination schedule consists of a
two-dose
regimen
with an interval of at least 21 days
between the first and second doses.
In the protocol used,
serum samples
were taken
prior to vaccination (basal level), 21 days after the first dose had been applied and 21 days after the second dose had been applied.
In this project, 600 serum samples were analyzed and more than 3000 determinations were carried out for the quantification of IgG antibodies against the Spike protein of the virus, as well as the quantification of neutralizing antibodies to the infection.
For the latter
, the ability of serum to prevent SARS-CoV-2 from infecting a cell was evaluated
.
This is a measure of how protective the antibodies generated are.
The study showed that the complete Sputnik V scheme induced
a humoral response against the Spike protein of the coronavirus in 100% of volunteers
analyzed in longitudinal study 21 after the second dose.
But it also revealed that the
median titer or amount of antibodies
in previously infected people who received a single dose of the vaccine
is
eight times higher
than that of those volunteers without previous infection who received the two-dose vaccination schedule.
"These results show that the humoral memory response of people previously exposed to the virus is robust and appears to be superior to that developed after two doses in people who have not faced the virus previously," Gamarnik said.
News in development.
