After an American and an Israeli study, a large British study has now also shown that the effectiveness of vaccines from Pfizer and AstraZeneca decreases over time. Furthermore, vaccinated people appear to contain as many virus particles as unvaccinated people. However, the risk of serious symptoms remains lower in the first group.
The AstraZeneca vaccine is still 61% effective against coronavirus infection 90 days after the second injection. The Pfizer vaccine is still 75% effective at that time. Researchers from Oxford University examined More than three million Nose and throat swabs. Efficacy declines most rapidly in people over 35 years of age.
The researchers further concluded that people who received a double vaccine had as many virus particles in their nose and throat after contracting the delta type as unvaccinated people. In the alpha variant, the number of virus particles in the double vaccinated was significantly lower than in the unvaccinated.
“When the delta variant appeared, we saw that the virus particles increased exponentially. Now we no longer see a difference in the amount of virus people get after the second vaccination”said Sarah Walker, Professor Medical Statistics and Epidemiology at Oxford University and Principal Investigator at Covid-19 infection survey.
According to her, it is still beneficial to get vaccinated, because the chance of getting sick remains lower than in the unvaccinated, but once you are infected, you carry the same amount of virus with you as the unvaccinated.
Researchers are still not sure whether vaccinated people become infected compared to those who were not vaccinated, and they expect vaccinators to get rid of the virus sooner, so they are no longer contagious. However, this is not supported by the facts.
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