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The Biontech / Pfizer vaccine is ready for use
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The delta variant of the coronavirus, which is now also predominant in Germany, seems to partially escape antibodies from those who have been vaccinated for the first time and those who have not been vaccinated.
The second vaccination dose is therefore mandatory for adequate protection against Delta.
A study in the journal "Nature" provides further information on this.
The Delta variant was first discovered in India and has spread to many countries around the world. It is considered to be significantly more contagious than previous variants and has been classified as worrying by the World Health Organization (WHO). According to the latest information from the Robert Koch Institute, the delta variant is now also predominant in Germany. Their share continues to increase sharply and has recently almost doubled again from 37 to 59 percent within a week - with still low absolute numbers.
Initial data had shown that the approved vaccines are also effective against the Delta variant when fully vaccinated.
The "Nature" study now also found indications that complete vaccination protection is necessary in order to combat the Delta variant.
In the laboratory tests, the antibodies formed after a single dose of the vaccines from Biontech / Pfizer and AstraZeneca were barely able to bind to the mutant, which was first discovered in India, and render it harmless, the researchers working with Olivier Schwartz from the Pasteur Institute in Paris report .
Both vaccines would only have caused an efficient reaction against Delta after the second dose - in 95 percent of the people.
After one dose, this was only the case with ten percent.
Vaccination is also important for those who have recovered
According to the study, antibodies in blood samples from unvaccinated convalescents are less able to bind to Delta than the alpha variant. After analyzing samples from convalescents who had already received a vaccination, the researchers said the results strongly suggested that such a booster would most likely protect convalescents against a variety of circulating strains of the virus, including Delta.
The scientists point out that for their study they only analyzed values from a few vaccinated people.
Results from such laboratory experiments cannot be directly transferred to vaccination protection in practice.
The team of authors writes that the so-called neutralizing antibodies examined would, however, be considered a strong indication of immune protection against symptomatic corona infections.
The human immune system not only defends itself against pathogens with antibodies, there is also cellular immunity, the so-called T memory cells.
Data from England have also already shown that a double vaccination with the funds from Biontech / Pfizer or AstraZeneca reduces the risk of a serious disease course with a stay in hospital.
However, according to the Ministry of Health in Israel, the effectiveness of the Pfizer / Biontech vaccination against the coronavirus has decreased significantly in recent weeks - even with two vaccinations.
Accordingly, since June 6, the effectiveness of vaccination in preventing infection and disease with symptoms in Israel has fallen to 64 percent.
The vaccination would still prevent 93 percent serious illness and hospital stays, it said.
However, the data from Israel are still provisional and should be viewed with appropriate caution.
mar / dpa
