Recovered, then vaccinated: What is “super immunity” about?

Updated on October 20, 2021, 3:10 p.m.

  • Do those who have recovered who are vaccinated against the corona virus have the best vaccination protection?
  • Several studies are currently investigating hybrid immunity.
  • What results did the researchers come to?nd how the virologist Janine Kimpel assesses the so-called “super immunity”.

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What offers the greatest possible protection against infection with SARS-CoV-2? Scientists all over the world are currently researching this. Several studies now show that the immune response of people who have recovered and who receive an additional vaccination after several months is particularly strong. How can this be explained and what virologist Janine Kimpel recommends.

What is the immune response to strongly modified virus variants?

What does the immune response of different groups of people look like against a strongly modified variant of the virus? Researchers from the USA investigated this question. In September, Theodora Hatziioannou and Paul Bieniasz from Rockefeller University in New York published the results of their research.

For their investigation, the researchers had a central part of the virus changed: The so-called spike protein that the corona virus needs to attach to and attack human cells. Hatziioannou and Bieniasz “built” an artificial spike protein that had 20 different gene mutations, including those classified as “worrying” like the delta variant. The result was a particularly aggressive, non-existent variant of the corona virus, which, however, cannot trigger COVID-19.

In medicine, by the way, this procedure is common practice: We speak of a pseudovirus which, unlike the real virus to be researched, is not contagious, but is very similar – and is modified and controlled accordingly for experiments.

In this case, the research team examined how the antibodies in different blood samples behaved when they came into contact with the artificial pathogen and which components of the spike protein were attacked by neutralizing antibodies. The result: only the antibodies of a certain group of people reached the aggressive spike protein: people who had recovered from COVID-19 and who had also received an mRNA vaccine later.

Memory cells significantly strengthen the immune response

Various studies show that those who have recovered who have also been vaccinated have very high levels of antibodies in general and also of neutralizing antibodies. In addition, they have a more diverse response to neutralizing antibodies than those who have recovered or who have only been vaccinated, i.e. they develop neutralizing antibodies against different areas of the surface protein. You should therefore also be well protected against infection for a long time.

There are now a few more research results, which indicate that the immune response of those who have recovered and who were later vaccinated with mRNA vaccines can be classified as particularly high. “Studies show that those who have recovered who have also been vaccinated have very high levels of antibodies in general and also of neutralizing antibodies,” says the virologist Janine Kimpel from the Medical University of Innsbruck when asked by our editorial team. “In addition, they have a more diverse response to neutralizing antibodies than those who have only recovered or who have only been vaccinated.”

Infection leads to “the formation of immunological memory cells”

This is also interesting for the reason that previous investigations Recoverers showed that certain neutralizing antibodies were no longer detectable in their blood after several months. This fact is now obsolete, it says in a public opinion of the Society for Virology. Rather, “a SARS-CoV-2 infection in humans leads to the formation of immunological memory cells”. These are in turn the “actual protective mechanism of the immune system against a new disease”.

Put simply: these B and T cells ensure that new antibodies are formed quickly as soon as they come into contact with the pathogen again. According to the Society for Virology, these antibodies are “much more effective” than the antibodies that were formed after the first infection – and could also “efficiently neutralize variants of SARS-CoV-2”. If those who have recovered now get vaccinated, these memory cells “respond” with the formation of particularly strong antibodies.

Longer lasting immunity from exposure to virus

Virologist Kimpel also explains the good immune response of people who have been vaccinated and recovered as follows: “In the case of respiratory viruses such as SARS-CoV-2, the antibodies on the mucous membrane are particularly important for protection against infection. These are made better by the infection in the respiratory tract than by a vaccination in the muscle. “

The hybrid immunity According to the current state of research, offers very good protection. However, the expert strongly advises against self-experiments: “As Unvaccinated Intentionally infecting it is dangerous and not advisable. With the delta variant, we see severe progression in young people without recognizable risk factors, which makes hospitalization necessary. “In addition, some of the patients show symptoms for several weeks or months after the infection (long COVID).

Ideally, according to the virologist, everyone should have a certain “basic immunity” – ideally through a vaccination – which is then refreshed at regular intervals through natural contact with the virus. “This should result in longer-lasting immunity on the mucous membrane as well.”

About the expert: Janine Kimpel is a virologist at the Medical University of Innsbruck and is currently researching the mode of action of cross-vaccination of vector vaccines and mRNA vaccines.

Sources used:

  • Written interview with Janine Kimpel
  • Nature.com: High genetic barrier to SARS-CoV-2 polyclonal neutralizing antibody escape
  • Society for Virology: Updated statement on the immunity of convalescents
  • Science.org: mRNA vaccination boosts cross-variant neutralizing antibodies elicited by SARS-CoV-2 infection
  • German Center for Infection Research: Glossary

mRNA vaccines are the great hope in the fight against the coronavirus. But how do these funds actually work? (Photo: iStock-kovop58)

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