The number of infections is increasing again in Germany. At the same time, the vaccination protection decreases for many. This is especially dangerous for older and weakened people. You should get a fourth injection. But what about the rest of the population?
A new corona wave is rolling towards Germany. "I assume that we will get a real summer wave this time," explains Federal Minister of Health Karl Lauterbach ntv. After a brief downward trend, the infection curve is rising again - and much earlier than expected. Hopes for the traditional summer effect fizzled out. The reason is, among other things, that the virus variant that is currently circulating is very easy to transmit and can spread well in summer, says Lauterbach. This increases the risk of infection for all age groups. At the same time, there are hardly any protective measures left. Should one try to get a second corona booster vaccination as a precaution? Instead of waiting until a vaccine that is better adapted to Omicron will probably be approved in the fall?
It has been months since the last booster dose for many people. Numerous studies show that the antibodies in the blood that are relevant for protection against infection decrease again after three months. And then there is the new variant BA.5, which is spreading throughout Germany and circumvents immune protection even more than previous Omikron lines. According to the Standing Vaccination Commission (STIKO), whether a fourth vaccination makes sense depends primarily on age and health. Since the beginning of February, the expert committee has been recommending a second booster dose for the following groups of people:
In the case of people at risk of health, the second booster should be given no earlier than three months after the first booster vaccination, and staff in medical and nursing facilities should receive the second booster no earlier than six months later. STIKO does not recommend a second booster vaccination for people who have had a corona infection after the first booster vaccination.
The STIKO justified its recommendation with the fact that "current data shows that the protection after the first booster vaccination against infections with the currently circulating Omicron variant decreases within a few months". This is "particularly important for people over the age of 70 and for people with immunodeficiency, as they have the highest risk of a severe course of Covid 19 after an infection".
Vaccinations should first and foremost help to avoid the worst, but not necessarily all infections. After three corona vaccinations, people over 70 and people with immunodeficiency have a lower risk of becoming seriously ill than without a vaccination. In many cases, however, it is still relatively high, especially if it has been months since the last vaccination.
In view of the summer wave rolling towards us, there are again considerations to introduce the second booster for everyone. But data from Israel show that for young and healthy adults, a fourth dose of an mRNA vaccine brings only "minor benefit." The study, published in the New England Journal of Medicine, looked at 274 workers at Sheba Medical Center in Tel Aviv who received a second booster shot four months after their first booster shot, either Biontech/Pfizer or Moderna. Each subject was compared to two participants in a control group who had only received three doses of the vaccine.
The result: The fourth dose increased the number of neutralizing antibodies in the study participants, which prevent the coronavirus from penetrating the cells. However, the values after the fourth dose were comparable with the values shortly after the third dose.
According to the study, the fourth dose offered little additional protection against infection with the omicron variant of the coronavirus. Subjects who received a fourth Biontech vaccination had a 30 percent lower risk of infection than those vaccinated with three doses. Subjects who received a fourth dose of Moderna only had an 18 percent lower risk of infection.
According to Charité virologist Christian Drosten, long-lasting immunity can also be achieved apart from adapted vaccines or fourth and fifth vaccinations. "The ideal immunization is that you have a complete vaccine immunization with three doses and on the basis of this immunization you are then infected with the virus for the first and second and third time and that you develop mucosal immunity without having to accept severe courses "Said Drosten in the NDR podcast. Anyone who has gone through this is probably immune for years and will not reinfect themselves again. The intensity of the infection determines how persistent the immune protection is.
The mucous membranes have their own immune system with a special form of antibodies, explained molecular biologist Emanuel Wyler to "Zeit". The mRNA vaccines can temporarily stimulate the production of such antibodies - but at some point they are broken down. Over time, according to Wyler, the amount of antibodies in the mucous membranes is no longer sufficient to ward off the corona virus. You get infected. The so-called T-cells then prevent a serious illness in most cases.
According to Drosten, a natural infection based on a complete vaccination stimulates mucosal immunity much better. The omicron variant and its rapid spread can act as a kind of natural booster.
In addition, anyone who has been vaccinated three times and is not particularly old and does not suffer from an immune deficiency is usually very well protected against Covid-19. Fortunately, this also remains the case with the new Omikron lines BA.5 and BA.4. According to the weekly report of the Robert Koch Institute (RKI), the triple vaccination has not lost its importance due to its “high protective effect against a severe course”, even in diseases caused by the omicron variant.
At the moment, the STIKO does not recommend a second booster vaccination for everyone. However, this can change depending on the infection situation. Even if the vaccine manufacturers bring a more potent vaccine onto the market, everyone could again be loaded for another injection. Moderna has already reported initial successes with the vaccine adapted to Omicron, and Biontech is also currently working on a corresponding vaccine. The hope: In the short term, as has already happened in other vaccination campaigns, infections in the population could be reduced and a wave of infections in the general population flattened out.
However, Lauterbach does not expect the adapted vaccines to be available until September at the earliest. Until then, according to experts, it is very likely that BA.5 will dominate the infection process in Germany. It is not yet clear whether the vaccines also provide better protection against these omicron subtypes. And even if they did, the vaccination's effect of stopping infections would very likely decrease again within a few weeks to months, as with previous vaccinations. So far, vaccination has only been able to prevent the virus from entering the mucous membranes of the respiratory tract for a short time.
But one thing is certain: Older and immunocompromised people should be given boosters again in view of the new corona wave. However, the offer of the fourth dose among older people has so far been accepted very hesitantly: only around 19 percent of the over 60-year-olds in Germany decided on the second booster dose by mid-June. Your family doctor can be the point of contact for first, second, third and fourth vaccinations. Mobile vaccination teams, company doctors, public health facilities, hospitals, vaccination centers and pharmacies can also vaccinate against Covid-19.