Who is eligible for another booster shot? The fourth vaccination with the wild-type vaccine that is available so far helps to reduce the risk for elderly people – for serious illnesses by 67 percent and for dying from Covid-19 by 72 percent. The STIKO currently recommends people over the age of 70 and those with a suppressed immune system to have their fourth vaccination three months after the previous vaccination. Getting the second booster, i.e. the fourth vaccination dose, is currently uncomplicated in Germany. A study from Israel shows that it also protects those over 60 years of age better from serious illnesses than just three vaccinations, but not very long-term with Omikron.
Therefore, the STIKO does not recommend a fourth vaccination dose. “The omicron booster will also be aimed primarily at risk groups so that they can refresh their immune response before autumn,” says Christian Münz. »Young and healthy people remain protected from a severe course by T cells, which the virus finds very difficult to escape.«
The summer wave could help people who do not belong to a risk group to get through the winter without further vaccination. “The more frequently the immune system encounters the antigen, the better the immune response,” says Christian Münz. “This stronger transmission that we now have over the summer makes the fall omicron booster not strictly necessary, at least for healthy people who become infected now.”
»We will all get infected again and again, at some point you will hardly notice it anymore«(Christian Münz, immunologist)
Münz calculates that as a healthy person you have to be in contact with the antigen every six months on average in order to be well protected. “If I have the choice in the fall, I’ll choose the vaccination,” says Münz. »But if I look at the infection process, then the booster from the infection is relatively common at the moment. We will all get infected again and again, at some point you will hardly notice it anymore.«
There is little to be said against the second booster
On the other hand, there is little to speak against an additional vaccination. “The safety data of the mRNA vaccines are very good, and it cannot be assumed that the immune system will be exhausted by vaccinations,” says Münz. “We’re constantly repelling pathogens. Some viruses even stay in the body forever and are kept in check by our immune system for life.«
From an immunological point of view, older people and people with immunosuppression whose last vaccination was more than four weeks ago can still be vaccinated with the wild-type vaccine without having to do without the omicron booster in autumn. “There should be at least a month between vaccinations,” says Münz. For that long, so-called affinity maturation improves the antibodies steadily, a process that is better not to be disturbed. “But then an additional confrontation with virus antigen strengthens the binding of the antibodies,” says the immunologist.