Leloir Institute study: 94% of those who received a single dose of Sputnik V generated antibodies

Candela Martin

04/13/2021 3:29 PM

• Clarín.com

• Society

Updated 04/13/2021 4:10 PM

A study carried out by a team from the Leloir-Conicet Institute on the Sputnik V vaccine highlighted the high effectiveness against the coronavirus of the Russian formula, and pointed out that it produces defenses against the SARS-Cov-2 protein

in 100% of the cases. individuals tested

after they received the two doses.

Another conclusion of the work is that those who were previously infected, when receiving a single dose, produce

higher levels of antibodies than

those who were never infected who received full immunization.

According to the study - led by Andrea Gamarnik, head of the Molecular Virology Laboratory of the Leloir Institute Foundation and senior researcher at Conicet -

94%

of the individuals in Group 1, those who had not had covid-19, showed presence of specific antibodies 21 days after

a single dose

of the vaccine;

while at 21 days after the second dose, 100% of them developed these antibodies.

What this study measured is the

presence of antibodies in vaccinated

, not the effectiveness of the vaccine against a possible contagion.

In other words, the amount of antibodies does not allow us to establish a percentage probability of getting sick after receiving Sputnik V doses.

Always among those who had not been sick, 96% of those 

under 60 years of age developed 

reactive antibodies;

while among those over 60, the reactivity was 89%.

"There is a similar response among the groups under and over 60 years old," confirmed Jorge Geffner, from the INBIRS-Biobank of Infectious Diseases, who worked on the research.

The infectologist Jorge Levalle, consulted by

Clarín

, considered that this study

"reaffirms the effectiveness of the vaccine

.

"

"The vaccine is quite effective and gives reasonable protection with a single dose," said Levalle when asked for a comment on the results of the work.

For the study, an analysis of 288

members of the health personnel

of hospitals in the province of Buenos Aires was carried out.

"So far 1,200 samples have been processed and more than 10,000 determinations have been made," the authors explained.

In the protocol used, plasma samples were taken prior to vaccination, 21 days after applying the first dose and 21 days after applying the second dose.

"The immune response observed 21 days after the second dose shows a

significant increase in antibodies

in all Group 1 volunteers," the report details.

This group was made up of people who did not experience the disease before being vaccinated. 

The so-called Group 2, made up of 61 people who had already had coronavirus, showed after the application of the first dose

"a robust response in all cases

.

"

“When we focused on those who were previously infected, we saw what happened when the first and second doses were given.

The basic finding is that in

those previously infected

, regardless of when they were infected, if a month or six months before receiving Sputnik,

with a single dose they produce higher levels of antibodies than

those produced with two doses those that had not been infected, ”Geffner said.

There were studies published in the United States with the same conclusion for Moderna and Pfizer vaccines, but not for Sputnik.

"The geometric mean of antibody titers in previously infected people who received a single dose of vaccine is

4.6 times higher

than that of those volunteers without previous infection who received the complete two-dose vaccination protocol," says a published report of the work. this Tuesday.

These results showed that "the previous infection generates

immunological memory

and that the reactivation of the memory cells against a dose of vaccine gives rise to

levels of antibodies much higher

than those produced in individuals who do not register previous infection".

This indicates, according to Levalle, that "with the first dose, patients who had a previous infection or had contact with the coronavirus raised an amount of antibodies practically similar to those who did not have contact with the virus and both doses were applied."

This is why the professional points out that “some studies begin to speak that

patients who already had coronavirus may need a single dose

, because the amount of antibodies present is similar to that generated by those who did not have contact with the virus and received the two doses ”.

Levalle clarified to

Clarín

that, beyond what the study shows, "that a vaccine that is designed for two doses is transformed into a single dose, in the absence of vaccines, is a public health strategy."

And adds: "This point infectologists

do not fall in grace

."

For Geffner "it

could happen that it is decided that the infected receive a single dose instead of two

."

Although he clarifies that it is not something that they can indicate, since before they need to see "how the antibodies are maintained over time".

"We will monitor the health personnel who participated in the study to see

how the antibodies evolve

over the months," added the researcher.

"The Sputnik V vaccine induces a humoral response against the SARS CoV-2 Spike protein in 100% of the individuals tested 21 after the second dose," the study found.

What is the

humoral response

?

It is the amount of antibodies that a vaccine or infection generates.

Plasma donation

On the other hand, the report ensures that "the information generated can be used to

improve plasma donation campaigns

", since "individuals vaccinated with two doses or vaccinated with one dose (previously infected) meet this requirement as potential donors".

LGP

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