Vaccination protects against the corona virus – at least in theory. But some Covid patients fall ill despite double vaccinations. This can have several reasons.
Frankfurt – The corona* Pandemic is picking up speed again worldwide. Also In Germany, the number of cases with the corona virus is increasing*. And that even though almost half of the German population has now been vaccinated twice. There are similar observations in Israel and Great Britain.
Even severe Covid courses that end in the hospital are apparently possible despite a double vaccination. But how can that be? There are mutliple reasons for this.
Reason 1: The Delta variant
Clearly, the delta variant has not exactly made the fight against the corona pandemic any easier. It spreads faster, is more aggressive – and is suspected of being vaccine* -Effect to reduce. According to the Ministry of Health in Israel For example, the effectiveness of the Pfizer / Biontech vaccine has been declining since the Delta variant*. According to this, the effectiveness of Biontech’s vaccine has fallen to 64%.
In fact, initial studies show that the vaccines – not just that Biontech / Pfizer* -Vaccine – are less effective against Delta than against the wild types of Sars-CoV-2. There is a risk of infection, especially with just one injected dose. Virologist had on it Christian Drosten* Already pointed out a few weeks ago. Drosten has repeatedly emphasized that a second vaccination is necessary. Missing a second vaccination is devastating, the Charité virologist recently explained in the NDR podcast “Coronavirus Update”: “Things like that should just not happen.”
The Standing Vaccination Commission (Stiko) recommends the so-called cross vaccinations for a higher effectiveness against Delta. People get the vaccine from in the first round Astrazeneca*, in the second round an mRNA vaccine (for example from Biontech) was injected. According to experts, the immune response should be significantly increased after two different vaccines. We are talking about a heterologous vaccination scheme.
A laboratory assistant stands at a fully automated PCR machine to examine corona smears. What are the reasons behind an infection despite a double vaccination? (Archive image)
© Boris Roessler / dpa
Reason 2: The effect of the corona vaccination can wear off after half a year
Another reason for getting Covid-19 despite double vaccinations can be the time factor. Because the effect of the vaccines probably wears off over time. Here, too, the first assumptions come from Israel, which with its vaccination campaign is already significantly further than Germany, for example. According to the Johns Hopkins University, almost 70% of the population there is fully vaccinated. Here, too, the vaccine from Biontech and Pfizer is particularly affected.
The manufacturer emphasized in a press release: “As has already become clear from the practical application data collected by the Israeli Ministry of Health, the protective effect of the vaccine against infections and symptomatic diseases decreases six months after the second vaccination.”
And in this way the manufacturer brings a third dose of vaccine into play. Soon A refresher of the corona vaccination with Biontech may be necessary* is the name of the proposal from Biontech. We are talking about a period of “six to twelve months after the complete vaccination”. For this suggestion there was harsh criticism from the WHO*. The WHO Director General, Tedros Adhanom Ghebreyesus, particularly criticized the ethical consequences of recommending a third corona vaccination from Biontech and Pfizer.
Minister of Health Jens Spahn* (CDU*) recently announced at a press conference that particularly vulnerable patients will be offered a third dose this autumn.
Reason 3: Even the corona vaccination does not work 100 percent
It applies to a flu vaccination, it also applies to Corona. A vaccination against the coronavirus never provides 100% protection. The admission studies have already shown that. Biontech / Pfizer as well Moderna* indicate a reduced risk of infection by 95% for their vaccines after double vaccination, Astrazeneca is at 70%.
After all: the manufacturers promise protection against a severe course of Covid-19 after the second vaccination. The problem: The data come from the registration studies in which people with a weakened immune system did not take part due to the high risk. In other words: The data are only valid to a limited extent for those people for whom the risk of a severe course after an infection with Sars-CoV-2 is increased.
In June, for example, Thomas Mertens, chairman of Stiko, said: “There are now several studies that show that vaccination against Covid-19 does not work as well in people whose immune system is slowed down by drugs as it does in others.” Depending on the extent of the immunosuppression and the drugs used, the immune response is significantly worse or even fails despite a full vaccination. “
Mertens therefore assumes that the double vaccination does not work as desired in some high-risk patients due to their already weakened immune system. According to initial studies, this mainly includes old people, cancer patients and organ transplants. (nc) * fr.de is an offer from IPPEN.MEDIA.
List of rubric lists: © Boris Roessler / dpa