News of vaccinated people receiving COVID-19 has appeared again and again in the news in recent weeks, but it is neither a reason to get angry nor an argument for rejecting vaccines. Even if someone experiences mild symptoms after a vaccination or is positive for the coronavirus, the vaccine continues to effectively do what it is supposed to do: prevent the serious progression of the disease and death.
How effective are currently approved vaccines?
All vaccines approved by the health authorities of the European Union (EMA) and the United States (FDA) have been shown to be highly effective.
For example, BioNtech-Pfizer and Moderna mRNA vaccines achieve 95% efficacy, while AstraZeneca vector vaccine achieves 76%, according to recent data. However, this means that it is still possible to become infected after vaccination.
However, if the efficacy is taken into account according to the severity of the course of the disease, all vaccines perform significantly better than without them. In case of infection, for example, vaccines usually prevent the kind of severe reaction that requires people to put themselves in fans, or even kill them.
Why have deaths from COVID occurred after vaccination?
However, in Germany there have been some cases where elderly people in nursing homes still had severe COVID-19 courses even after vaccination. Some even died.
The Robert Koch Institute (RKI), Germany’s central infectious disease authority, writes that two circumstances can lead to disease after vaccination, that is, if the infection occurred shortly before vaccination or in the days immediately following. .
The reason? The body needs about two weeks to fully increase immunity. Therefore, complete protection is only achieved two weeks after the patient has received their second vaccine.
What does sterilizing immunity and functional immunity mean?
When it comes to vaccination, doctors distinguish between sterilizing and functional immunity. Sterilizing means that a vaccinated person can no longer infect anyone. Early evaluations of BioNTech-Pfizer vaccines administered in Israel showed that people who had been vaccinated twice had a 92% lower risk of infecting other people.
In this regard, it is safe to say that the BioNTech-Pfizer vaccine offers a fairly high sterilizing immunity against the most common variants of coronavirus. Although there are still no conclusive figures for other vaccines, the effectiveness is likely to be comparable.
However, only when there is clear evidence that vaccinated individuals cannot infect others, or when sufficiently high “herd immunity” has been achieved, can authorities exempt vaccinated individuals from obligations such as wear masks or observe physical rules of distancing.
However, although we have not yet reached this point, it has been shown that all currently available vaccines offer functional immunity, that is, they prevent or reduce the risk of severe symptoms. And even in rare cases of disease, vaccines have significantly reduced the course of the disease.
How long does a COVID-19 vaccine protect against infection?
To date, there is no clear answer to this question for any of the vaccines. Before approving vaccines, researchers must determine their safety. And in phase III vaccine development, experts focus on functional efficacy.
But only in time will we learn how long the immunity of COVID vaccines lasts. That is why the period after vaccination licensing is also known as phase IV vaccine development. We are now in the middle of this phase. Reliable statements about the duration of immunity will only be possible after several months or even years.
What are the effects of mutations and variants?
Each vaccine responds differently to viral mutations. For now, vaccine developers are concerned about the P.1 variant found in Brazil. This mutant variation has infected many people even though they had previously been infected or vaccinated. The South African variant B.1.351 can also infect vaccinated people, as medical experts were able to show with the AstraZeneca vaccine.
But here too doctors believe that vaccines will at least lead to milder courses of the disease and reduce the number of patients in need of intensive care medical treatment.
This has to do with the fact that immunity consists of two components: the immunity of the antibodies against the ear protein, in which the individual components can mutate, and the immunity of the T cells, which continues to be protected even when antibodies are no longer as effective.
