The vaccinations against the coronavirus reduce infections and prevent severe courses and deaths. And yet: In rare cases, people who have been vaccinated twice may become infected or even develop symptoms. Why is that not surprising.
At first it rose slowly, then quickly, now it is slowing down again: The vaccination rate is getting a lot of attention these days. According to the Robert Koch Institute (RKI), more than 60 percent of the population received at least one dose of vaccine. 48 percent are considered fully vaccinated. That corresponds to almost 40 million people.
At the same time, however, there is also a less pleasant development: The number of new infections recently increased again, which is mainly attributable to the particularly contagious virus variant Delta, which is now also dominant in Germany. has been rising again for a few days and is currently at 12.2. In the previous week the value was 8.0.
As a result, an increasing number of people who have been fully vaccinated are increasingly coming into contact with the virus. In the vast majority of cases, the virus loses out. The antibodies produced by the vaccinations intercept the virus, reduce infections and prevent severe courses and deaths. recently underlined how strongly vaccinated people benefit from the protection against severe courses: 99.9 percent of hospital admissions by Corona concerned unvaccinated or people without complete vaccination protection.
The Federal Center for Health Education also writes: “Vaccines against the Sars-CoV-2 coronavirus prevent you from contracting Covid-19 and offer highly effective protection against serious illnesses.” Their benefits far outweigh possible risks.
No vaccine provides 100 percent protection
In rare cases, however, the virus may prevail and infection may occur even in those who are fully vaccinated. If symptoms also occur, doctors speak of a so-called vaccination breakthrough.
That sounds threatening at first, but it means nothing else than that a vaccination does not offer one hundred percent protection against infection and disease – which has been known for a long time and was also observed in the approval studies of the vaccines.
What the effectiveness says
Example: Biontech. The vaccine showed an effectiveness of 95 percent in the final and large approval study. It prevented 95 percent of Covid 19 diseases through original variants. That is a very good value. However, this does not mean that for every 100 people vaccinated, 95 remain healthy while five become ill. Rather, the value is a measure of the risk reduction.
What this means becomes clearer when you look at how vaccines are tested. Large approval studies always have several thousand test subjects. You will be divided into two groups. One receives the vaccine, while the other receives an ineffective placebo. The researchers then check how many people get Covid-19 during the follow-up period. The difference between the two groups determines the effectiveness.
Here is a fictitious example calculation: Assume that a vaccine study has a placebo and a vaccine group with 5200 subjects each. In the placebo group – purely fictitious – 150 people contract Covid-19. If the vaccine is 95 percent effective, only a little more than seven people in the vaccine group fall ill (7.5). There are few – but not zero.
In its situation report of July 14, the RKI lists 5374 vaccination breakthroughs since the beginning of February. 676 of them had to be treated in a hospital. The vast majority of them were older than 60 years (614). 40 million people in Germany are currently fully vaccinated. The number of known vaccine breakthroughs is therefore comparatively very low.
that it is primarily people who have previously had illnesses who have had to be treated in a hospital despite having been vaccinated twice.
“Prophylaxis is no guarantee of success”
The doctor and author Natalie Grams-Nobmann recently emphasized the benefits of vaccinations on Twitter: “If you don’t understand why you can get COVID-19 despite a complete series of vaccinations, you don’t understand why you can get pregnant despite the pill,” she wrote. Prophylaxis is not a guarantee of success, but the risk is much lower.
It will now be important to find out whether certain mutants lead to vaccination breakthroughs more frequently and to what extent possible third-party vaccinations can prevent this. For particularly vulnerable groups of people – including the elderly and the chronically ill – a so-called booster vaccination has been discussed for a long time. The reason: Studies show that the immune response in these groups of people can be weaker than usual – which also reduces protection against infection and serious illness. According to this, some cancer patients or people who have had organ transplants can be affected.
For the virus variant Delta, there are also initial indications that it can – if not undermine its effectiveness.
However, whether vaccines prevent symptomatic diseases is not the only yardstick by which the success of the vaccine is measured. Vaccines that reliably prevent severe disease and death are also a real “game changer”. And on these two points, the current vaccines still seem to be doing well. They therefore continue to protect effectively against severe courses with the virus variant Delta,
Good protection against serious illness
The vaccine from Biontech / Pfizer protected 96 percent against hospitalization because of a delta infection. The Astrazeneca vaccine came in at around 92 percent. suggest that the Biontech vaccine fends off 93 percent of serious illness and hospitalization. A complete vaccination is important.
But it is also clear: the vaccines cannot prevent severe courses in every single case. Similar to infections, protection is not 100 percent. There will always be people who, despite a complete vaccination, can become infected and become seriously ill. As tragic as these cases are, if this led to fundamental doubts about the benefit of the vaccination, it would inevitably mean even more suffering.
According to calculations by the RKI, at least 85 percent of the population would have to be vaccinated in order to largely contain a fourth wave towards autumn with all its negative side effects. Germany is still a long way from that.
