09/02/2021 at 7:47 PM CEST
The natural immune protection that develops in our body after having overcome a SARS-CoV-2 infection offers considerably greater protection against the Delta variant of the coronavirus than the two doses of the vaccine (Pfizer-BioNTech is the one injected in the country), according to an extensive study carried out in Israel.
It shows that people who have overcome the disease are much less likely to be hospitalized with severe COVID-19 or even to develop symptoms.
It is further proof of the power of the human immune system.
Advantages of natural immunity, in data
In this first study, led by Tal Patalon and Sivan Gazit and comparing more than 32,000 people, it found that:
Those who were vaccinated in January and February, about 5 months later (in June, July and the first half of August) were 6 to 13 times more likely to be infected than unvaccinated people who had already passed the coronavirus. Symptomatic COVID-19 was 27 times higher among those vaccinated; the risk of hospitalization was 8 times higher.
The differences are huge, but it must be pointed out that the numbers of infections, hospitalizations and other events analyzed for the comparisons were too small.
Stronger and stronger protection
For many infectious diseases, naturally acquired immunity is known to be more powerful than vaccine-induced immunity and often lasts a lifetime.
In this specific case, data is published showing that people recovering from a SARS-CoV-2 infection continue to develop increasing numbers and types of antibodies directed against the coronavirus, for up to at least 1 year.
However, people who got vaccinated twice seem to stop seeing increases “in the potency or breadth of the general memory antibody compartment” a few months after their second dose.
But infectious disease experts want to make clear that COVID-19 vaccines are also highly protective against severe disease development and death.
And they warn that it is not worth trying to get infected to achieve later protection. Because, as the immunologist Michel Nussenzweig says, “if people think about going out and getting infected & mldr; someone could die.
An added dose, is it even better?
In another analysis, the researchers compared more than 14,000 people who had passed the infection and were not yet vaccinated, with an equivalent number of people who, once the disease was over, received a dose of the Pfizer-BioNTech vaccine.
That dose, added to the protection that the person who suffered the disease already had, causes the immune system of those people who develop natural immunity to SARS-CoV-2 and then get vaccinated to produce exceptionally broad and potent antibodies against the coronavirus.
– “We continue to underestimate the importance of natural immunity to infections, especially when the infection is recent.”
– “And when we also reinforce it with a dose of vaccine, it takes it to levels that cannot be equaled with any vaccine in the world at this time.”
Now we need to take one more step to try to answer the discussion about whether previously infected people need to receive two doses of the vaccine or just one.
At the moment, some countries like the United States are in favor of putting the complete regimen to those who have passed the infection, while others like Spain, Germany, France, Italy and Israel, administer only one dose of the vaccine to previously infected people.
The largest study in the real world
The authors consider this to be the largest observational study ever done in the real world, and that it allows comparison of natural and vaccine-induced immunity.
Conducted in one of the countries most vaccinated against COVID-19 in the world, it has medical data on tens of thousands of Israelis and the record of their infections, symptoms and hospitalizations between June 1 and August 14, when in Israel the Delta variant predominated.
The research impresses scientists to the point that an immunology researcher goes so far as to say:
– «This is a textbook example of how natural immunity is actually better than vaccination. To my knowledge, this is the first time that this has actually been shown in the context of COVID-19. “