FAQ
Status: 09/24/2021 2:56 p.m.
Vaccination breakthroughs – this is what it is called when people get Covid despite being completely vaccinated. Why is that? How well does the vaccination protect? Here are the most important questions and answers.
How many people are affected by vaccination breakthroughs?
The Robert Koch Institute collects all cases of people who get Covid despite being vaccinated. There have been after these since the start of the vaccination campaign data in Germany 47,753 likely vaccine breakthroughs. On the basis of this number, the RKI estimates the effectiveness of the vaccine for the past four weeks at 84 percent for the age group under 60 years and at 83 percent for people over 60 years.
The current report by the RKI also states that the delta variant of the virus is now responsible for 99.9 percent of infections in Germany. The high proportion of the delta variant also increases the number of vaccination breakthroughs, as this variant of the virus is significantly more contagious than the original form.
Why are there vaccination breakthroughs at all?
It was already known after the approval studies that people would become infected even though they were vaccinated. Although these showed that the vaccines worked very well, none of the vaccines were 100 percent effective in the studies either. Such breakthroughs in vaccination are normal and are also known from other vaccines.
The fact that the number of such breakthroughs after the Covid vaccination is currently increasing is also due to the fact that many no longer adhere to hygiene rules so strictly, says Katherine O’Brien. She is an immunologist and heads the Department of Immunizations and Vaccinations WHO. However, the safety precautions are important to keep the spread of the virus in check: “If the virus spreads faster and further, then we come into greater contact with it – this also affects people who have been vaccinated.” In rare cases, these could then become ill.
How long does the vaccination last?
In addition, the vaccination protection decreases over time. The longer the immunization was complete, the higher the likelihood of falling ill despite being vaccinated, according to one British study. Because the antibody level that the body has built up against the coronavirus drops some time after the vaccination. However, this does not leave the body defenseless. Because the immune system consists of other defense cells that are activated by the vaccination. So can the Immune defense reactivated relatively quickly, even if the antibodies are barely measurable after a few months.
It is likely that people who become infected with the coronavirus despite being vaccinated can also infect others – at least in such cases virus genetic material was found in the smears. How long one is contagious after a breakthrough in vaccination has not yet been finally clarified.
Who is particularly affected?
Not all people have the same risk of contracting Covid despite being vaccinated. People with a weakened immune system are particularly affected, explains O’Brien. This can be the case, for example, after an organ transplant or during cancer treatment. But the risk of a vaccination breakthrough also increases with age. Because the immune system becomes more inflexible with age – especially when it is supposed to learn how to ward off previously unknown pathogens. The result: the vaccination does not work as well or not at all, and long-term protection cannot be built up.
This can also be seen in the current figures from the Robert Koch Institute: In the age group over 60, the proportion of vaccine breakthroughs in the past four weeks among symptomatic Covid-19 cases is almost 45 percent. This value is 21.3 percent for younger adults and 1.4 percent for adolescents. However, the vaccination rate for people over 60 is also significantly higher than for the younger age groups.
How does an immune response work?
The vaccination stimulates the body to produce antibodies. They arise within days and weeks from specialized blood cells. Immunologist Carsten Watzl calls the antibodies an “army” that must grow as quickly as possible through cell division. If the real pathogen invades the body again, be prepared. The antibodies blocked the binding site of the virus, and then it could no longer infect the body’s cells.
Already infected cells are simply destroyed by T cells, also known colloquially as T killer cells. It prevents the disease from spreading throughout the body.
The second important part of the immune response are so-called memory cells. These are found in both the B cells responsible for antibody formation and the T cells. After an infection, the body produces these memory cells that contain information about a pathogen such as SARS-CoV-2. If the infection is re-infected, they can start the immune reaction, produce antibodies and form specific T cells within a day. So the virus can be fought quickly. Researchers suspect that this also seems to be the case with SARS-CoV-2. They were able to show that those who have recovered form memory T cells that remain in the body for a long time.
How are the disease processes?
Vaccinated people have a clear advantage – even in the event of an infection. Because on average they were no longer as sick, explains the immunologist O’Brien. Many are unlikely to notice an infection or develop only mild symptoms.
But here too, not all age groups are equally affected: In a study by the Yale School of Medicine in the USA, the data of almost 1000 Covid patients were analyzed. The group of people who became seriously ill despite being vaccinated and had to be treated in hospital was 80.5 years old on average. Many had previous chronic illnesses. In Germany, 585 people over 60 have died of a corona infection despite being vaccinated. So far there have been three in the under 60 age group.
How good is the protection against a severe course?
But the same applies to older people: Overall, the vaccination continues to provide good protection against a serious or fatal course. The effectiveness of the vaccinations in the older group declines over time – but when it comes to preventing severe courses, according to the latest, protection is in place Israeli dates in all age groups at over 80 percent.
According to the Robert Koch Institute, with a full vaccination in Germany, 95 percent of people over the age of 60 are protected from hospital admission, 96 percent from treatment in the intensive care unit and approx. 93 percent from a fatal one Course. These numbers relate to reported vaccination breakthroughs over the past four weeks.
How is it in other countries?
Like the Robert Koch Institute in Germany, the national health authorities in other countries are also closely monitoring the number of vaccination breakthroughs. In the USA there was according to the epidemic protection agency CDC of September 13, 15,790 people who were admitted to hospital with Covid disease despite being vaccinated or who died from it. With over 178 million US Americans vaccinated, according to the agency, this number is in line with expectations – the vaccines are still expected to be highly effective.
Data from Israel caused a sensation: 60 percent of people there who are treated with a corona infection in hospital are vaccinated. But experts like Jeffery Morris, professor of biostatistics at the Perelman School of Medicine at the University of Pennsylvania, warn that the conclusion that the vaccination no longer works after a few months is not enough. The proportion of vaccinated among Covid patients in hospitals in Israel is high, but this is mainly due to the high vaccination rate, especially among the older population in Israel. There are only a few unvaccinated people who are seriously ill with Covid. That distorts the picture.