Over time, the immune protection decreases after vaccination. A so-called vaccination breakthrough becomes more likely. How are the infections going despite the vaccination? And what does that mean for the booster vaccinations? A look at the data.
Double vaccinated and still infected with the coronavirus? Again and again one hears of such cases in family or friends. If affected people show symptoms, have a fever, cough or sore throat, doctors speak of a so-called vaccination breakthrough – i.e. a Covid 19 disease despite a full vaccination. A little more than The Robert Koch Institute (RKI) has 214,800 such cases counted since the beginning of February 2021. Face it more than 56 million people fully vaccinated in Germany.
More important than the question of whether people who have been vaccinated can be infected with the virus, however, is to look at how Breakthrough infections are occurring – i.e. whether sick people are protected from severe disease, hospitalization, intensive care or even death from Covid-19 despite their sore throats. After all, it is these cases that need to be prevented – not only in the interests of the individual, but also with a view to the capacities in the clinics.
The fact that vaccinated people can contract the virus and develop a fever or cough for a few days is initially not surprising and was already shown in the approval studies. The particularly contagious virus variant Delta also puts immune protection to the test and means that vaccinated people become infected slightly more often than with earlier virus variants. In addition: the immune protection against infection begins to decrease about two to three months after the vaccination and is already noticeably reduced after four to six months.
An American evaluation of more than 3.4 million electronic medical records showed that the infection protection of Covid-19 vaccinated persons (Biontech / Pfizer) against Delta decreased from 93 percent to 53 percent in this time window. On the other hand, there are data that make it clear that the majority of unvaccinated people are still infected with the coronavirus – the incidences are significantly higher here, even if certain distortions are to be expected due to different test behavior.
Coronavirus: Unvaccinated people are more at risk
But what is known about disease progression after a breakthrough in vaccination? Michael Klompas, a professor at Harvard Medical School, has that question in a review article followed up and has positive things to say: Vaccinated people are much better protected in the event of an infection with Sars-CoV-2 than unvaccinated people.
“Vaccinated people with breakthrough infections develop symptoms less often, develop severe symptoms less often, recover more quickly from their illness and have to go to hospital less often than unvaccinated people,” writes the doctor and expert on infectious diseases in the Jama editorial. Vaccinated people are also much better protected against death from Covid-19: their risk of dying from Covid-19 is 32 times lower than that of those who have not been vaccinated, such as a recent evaluation by the British statistical agency revealed.
Further data support the high level of protection, including a study by the French Epi-Phare Institute with data on around 7.7 million fully vaccinated people aged 50 and over and just as many unvaccinated people. Accordingly, the vaccines from Biontech / Pfizer, Moderna and Astrazeneca reduced the number of expected severe disease courses in this age group by more than 90 percent.
What follows from this data? Vaccinated people initially have a much lower risk of getting seriously ill with Covid-19 or even dying than people who have not been vaccinated. But it is now also known that not all people benefit equally from basic immunization with two doses of vaccine. High-risk groups, including people with autoimmune diseases, certain types of cancer and the elderly, usually develop fewer antibodies from the outset than younger, healthy people. In addition: not only the effectiveness of the vaccine against infection, but also that against hospitalization and death diminishes somewhat over time, albeit much more slowly than the protection against infection.
An evaluation that has not yet been assessed the British health authority “Public Health England” shows that the vaccine effectiveness against hospitalization is still 77 percent after five months – for the vaccine from Astrazeneca. The Biontech / Pfizer vaccine performed better: after five months it was still 92.7 effective against hospitalization and thus against correspondingly severe courses.
More vaccinated people, more vaccination breakthroughs
The figures make it clear that the majority of those who have been vaccinated are still very well protected from severe disease months after the vaccination – but that there are also people who can become seriously ill despite being vaccinated. A study from Israel came to the result that older people and people with certain pre-existing illnesses are more likely to need hospital treatment after a breakthrough vaccination – i.e. those people who are already at an increased risk of severe disease and who are permanent Vaccination Committee (Stiko) We have been recommending a booster, i.e. a booster, for several weeks from six months after the last vaccination. In individual cases or if there is sufficient capacity, the vaccination interval could also be shortened “considered” for five months, writes the Stiko.
Currently, 37.8 percent of the over 60-year-old Covid cases in intensive care units are “likely vaccine breakthroughs”, announced the RKI. In the younger age group of 18 to 59 year olds, the number is lower – at 13.1 percent. It should be noted, however, that the vaccination rate in both age groups is quite high. The epidemiologist Berit Lange from the Braunschweig Helmholtz Center for Infection Research recently made it clear to the “Braunschweiger Zeitung” why this point is so important: “There are no vaccine breakthroughs only where no one is vaccinated,” she said. “Conversely, if 100 percent of the people were vaccinated, then 100 percent of the corona cases in the intensive care units would also have to be vaccination breakthroughs. The bottom line is that there would be far fewer cases than now.”
Close vaccination gaps, boost
From all these numbers and statistics, two things follow that are important in the short term and in the current situation: First, the knowledge that vaccination protects and that unvaccinated people, especially the elderly and those with previous illnesses, are urgently advised to get vaccinated – especially in the face of it the current high number of infections. And secondly: That risk groups who were vaccinated a few months ago particularly benefit from a booster. It also lowers the risk of severe disease, hospital admissions and death and causes the number of antibodies and immune cells in the body to rise again and sometimes even exceed the level after a second vaccination.
The booster has also been recommended by Stiko to adults aged 18 and over since this week. In addition to “maintaining individual protection”, an additional consideration also plays a role in the extended recommendation: If a sufficient number of people are boosted, including in younger years, this will in all probability also have an influence on the spread of the virus. This would create a kind of additional protective screen for risk groups.
It is more than questionable whether the current vaccination rate alone is sufficient to suppress the dynamically growing number of new infections. So far only Almost 5.2 million booster vaccinations were given in Germany.
The federal and state governments decided on Thursday that stricter corona protective measures and restrictions should take effect as soon as the hospitalization incidence reaches certain thresholds. Experts are certain: the measures, especially those to restrict contact, are needed when the number of infections and hospitalizations is particularly high.