Irene Hartmann
07/01/2021 6:01 AM
Clarín.com
Society
Updated 07/01/2021 12:12 PM
Two papers in the prestigious journal
Science
confirm the insurmountable
synergy
of two almost common events at this point in the pandemic:
having had
coronavirus
and having received a dose of a
vaccine.
The combination of these facts (which, isolated, are much less relevant) would surpass, in terms of immunity, the administration of two doses to the "virgins" of Covid.
Two clarifications: the data are excellent and speak of an
improvement in immunological memory of between 5 and 10 times
more than in the “only recovered” or “only vaccinated”.
Now, with almost 100,000 deaths from Covid in Argentina, it goes without saying that none of this should be interpreted as a suggestion to go out and get infected.
On the contrary, the information aims to add peace of mind to the more than 4 million recovered and urge them, as they are summoned,
to get vaccinated
.
As is known, human immunity is complex and multifaceted.
Among the various types of antibodies, some highly mentioned are those that have the ability to neutralize Covid: neutralizing antibodies.
Vaccination against Covid, in the Quilmes Beer Park, province of Buenos Aires.
/ Xinhua
However, a second immunity plays a key role, as a back-up, although it develops more slowly: it is
immunological memory
or
cellular immunity
, mediated by B and T lymphocytes.
Beyond the technicalities, the interesting thing is that, until now, the different experts that
Clarín
had been consulting "assumed" that immunological memory had to play an important role against Covid.
The papers published by Science now give this question a more complete dimension.
Both were published on June 25.
In the same issue of the journal, a short article introducing the auspicious data from those papers points to the "
brilliant evolutionary strategy
" of memory cells, specifically
B
cells
, which are the ones that matter most to us now.
What do those lymphocytes do?
In the event of reinfection (in the case of hybrid immunity, the second infection would be stimulated by the vaccine), the memory B cells increase the production of antibodies.
But they do something else, which sounds amazing.
"They encode a library of antibody mutations."
That is, they create a "
pool of immunological variants
", clarifies the text.
In other words, the organism displays a series of "
preventive guesses about which variants could arise in the future
."
Logically, variants of Covid.
The papers
The first of these works comes from experts at the Fred Hutchinson Cancer Research Center in the United States.
The second is endorsed by various scientific institutions in England and Australia.
For those concerned, the titles are “
mRNA vaccination boosts cross-variant neutralizing antibodies elicited by SARS-CoV-2 infection
” and “
Prior SARS-CoV-2 infection rescues B and T cell responses to variants after first vaccine dose
”, respectively ( “Vaccination with mRNA increases neutralizing antibodies of cross-variants caused by SARS-CoV-2 infection” and “Previous SARS-CoV-2 infection rescues B and T cell responses against different variants after the first vaccine dose ”).
The experts focused on
very small groups of patients
.
In the first there are only 15 people.
In the second, 51.
Asked about the relevance of the results,
Jorge Quarleri
, expert in virology, doctor in Biochemistry and Principal Investigator at INBIRS-Conicet, highlighted the
qualitative
weight
versus the quantitative
weight
of the cohorts.
"They did not do what is often styled, which is to take plasma from patients and test if it can neutralize the virus, but they measured the cellular response, an enormously laborious and substantially more informative evaluation because it manages to get to the why," he said.
Gamma and Delta
The first paper highlights that although the observed Covid sera (prevaccination) had neutralized the Wuhan variant and, sporadically, the Beta ("former" South Africa), a dose of vaccine "
increased the neutralization titers against all the variants
up to 1,000 times
”.
Nasopharyngeal swab for detection of Covid./EFE
In the second study, a group of health workers, with and without previous infection, was investigated.
The conclusion was that, after a dose of vaccine, the individuals who had had Covid showed
greater cellular immunity
, in addition to effective neutralizing antibodies against the Alpha and Beta variants.
And, on the contrary, "
those who had not had Covid had a reduced immunity against the variants,
" he points out.
The two studies indicate that, a) hybrid immunity is superior to that obtained with complete vaccine schedules in "virgin" or "naive" Covid patients.
And, b) that patients who had coronavirus (at least, those who had symptoms) have a "ceiling": the second dose does not increase their immunity.
Perhaps due to a matter of dates, these papers do not allude to the Delta variant of concern.
However, in Argentina, it is concerned if hybrid immunity would be equally robust against this variant that emerged in India, as well as against Gamma (former Manaus), one of the most circulating here.
The issue of Gamma is not minor: this Wednesday, a report from the Country Project warned the decrease of up to three times in the neutralizing capacity of the antibodies produced by the Sputnik V vaccine when facing it.
Although the brief information provided in that report would require further study, it is evident that, with a low titer of neutralizing antibodies, the role of immunological memory is central.
Like a kind of "life preserver".
Thousands of people who had Covid could be positively deploying this other protection against the virus.
And
even more so if they are vaccinated
.
For Quarleri, a thorough understanding of hybrid immunity is valuable at this time: "Even the most 'escapist' to vaccines (
Beta
) was subjected to the intensity and breadth of hybrid immunity. I think there will be no differences when dealing with the Delta variant ”.
$
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