How long does protection last for those who have had covid? (and how vaccination influences)

How long does the immune response last to the novel coronavirus SARS-CoV-2 is a question answered over time and they add up studies with more extensive follow-ups. To the encouraging evidence gathered so far, is added new work published today in the journal Nature, which concluded that the antibodies generated by people with Covid-19 are maintained over time and are improved. with vaccines.

An international team of scientists led by the American Michel Nussenzweig, head of the Molecular Immunology Laboratory at Rockefeller University and a researcher at the Howard Hughes Medical Institute, has discovered that antibodies continue to evolve for a period of 6 to 12 months and that vaccination increases the response, the researchers therefore concluded that the immunity against COVID-19 could be long lasting.

“Neutralizing activity and the number of RBD-specific memory B cells remain relatively stable for 6 to 12 monthsThe article says. RBD is the peak of coronavirus peaks and represents the key to entry of the virus into body cells

To reach these conclusions, Nussenzweig and his team analyzed blood samples from 63 people that had been recovered from covid photos in 2020.

Of the total number of participants, 26 had already received at least one dose Moderna or Pfizer-BioNTech vaccines, and found that between 6 and 12 months later, the range of antibodies produced increased in both range and potency.

“Very effective”

Later, when individuals were vaccinated, they began to produce antibodies “very effective” against the different variants already circulating of SARS-CoV-2.

One year after infection, the neutralizing activity against all forms of the virus included in this study was lower in people who had not been vaccinated than in those who had been.

This, based on the research findings, suggests that vaccination strengthens immunity in those who have already gone through the disease.

“More than a year after its onset, the pandemic remains difficult to control despite the availability of several excellent vaccines. Progress in control is hampered by the appearance of variants which appear to be more transmissible and more resistant to antibodies “, state the authors of the work.

No obstante, en ese sentido señalaron que “la vacunación aumenta todos los componentes de la respuesta humoral (N de. R: que incluye a los anticuerpos) y, como se esperaba, da como resultado actividades de neutralización del suero contra variants of interests that they are comparable or better as neutralizing activity against the parent virus. “

In this sense, the researchers pointed out that if cells evolved in a similar fashion in vaccinated people who had not had the disease, a properly timed “booster” vaccine might also be able to generate a protective immunity against viral variants circulating around the world.

“The data suggest that immunity in recovering people will be very resistant and that those who have gone through the disease and are receiving the available mRNA vaccines will produce antibodies and memory B cells that should protect against the circulating variants of SARS-CoV-2, ”they concluded.

Study in Argentina

A study carried out in Argentina by Andrea Gamarnik, head of the Molecular Virology Laboratory of the Leloir Institute Foundation (FIL) and senior researcher at CONICET, also provided very positive data on the protection generated by vaccinated people having overcome the infection with Covid-19, but in this case with the Sputnik V vaccine, based on viral vectors, a technology different from mRNA.

The study, carried out in the Province of Buenos Aires, involved 288 vaccinees, of whom 61 had been previously infected. In them, the amount of antibodies found after receiving a single dose of Sputnik V vaccine was 4.6 times higher to that of volunteers without previous infection who received the vaccination schedule in two doses.

“These results indicate that a previous infection generates immune memory and that reactivation of the immune system against a dose of Sputnik V vaccine results in antibody levels much higher than those developed after two doses in people who have never faced the virus before “, analyzed Jorge Geffner, member of the team that carried out the study and principal investigator of CONICET at the Institute for Biomedical Research on Retroviruses and AIDS (INBIRS), when the results of the work were communicated in April.