The corona vaccinations work, but only for a certain period of time. A few months after the bite, the protection decreases significantly. This is the result of a research group led by the physician Peter Nordström from the University of Umeå in Sweden. Depending on the vaccine, there are differences, and it doesn’t matter how old you are and what gender you belong to.
The study compared more than 840,000 people who had been vaccinated with the same number of people who had not been vaccinated. By the end of the second month, the protection of all vaccines was around 90 percent. After that it went downhill. After seven months, the average protection fell to 23 percent, a level at which it is no longer statistically relevant.
There are, however, noticeable differences in the effectiveness of the individual vaccines. With two doses of Astrazeneca, no effect was detectable after four months. With two cans of Biontech this was at least the case after seven months. Moderna achieved 60 percent protection after six months, as did cross-vaccination with Astrazeneca and mRNA. Moderna is therefore the winner for the time being. Apparently the vaccinated persons were missing for statements about a longer observation period.
Older studies had confirmed that Biontech and Astrazeneca were more effective, but under different conditions. At that time, the delta variant had not yet caught on. The new investigation was carried out over a period of nine months up to the beginning of October. During this period, the proportion of the delta variant also increased. That could be one of the reasons for the result. In the case of a persistent delta variant, the vaccination protection could be lower right from the start and therefore decrease less sharply later.
In any case, the protection against hospitalization and death proved to be more stable. However, here too the effectiveness fell from around 90 percent at the beginning to a good 40 percent after around six months, especially for people aged 80 and over. For younger people, the protection against severe disease remained stable at around 80 percent even after six months. No differences could be found between the various vaccines because of the insufficient number of cases.
Another result: In addition to the elderly and people with previous illnesses, men also have an increased risk of getting seriously ill despite being vaccinated. Between six and nine months after the second dose, women still had a good 70 percent and men a good 50 percent protection.
