Vaccines from Pfizer, Moderna and AstraZeneca offer high protection against the symptomatic diseases caused by the Delta mutation, according to the findings of a Canadian study. In fact, according to the same research, protection already exists with the administration of the first dose.
Previous studies have shown limited efficacy of vaccines. Although the researchers measured the performance after the first dose, they point out that the second dose is required to be fully functional.
According to Politico, the investigation took place under real circumstances. So far it has not been evaluated by peers (peer review) but it was first published on July 16. The researchers compared the efficacy of the three companies' vaccines with the mutations of concern and concluded that even a single dose of these vaccines, approved in the EU, provides significant protection against symptomatic infections and serious side effects.
How protection is formulated per vaccine
The data show that the Pfizer vaccine provides 56% efficacy against symptomatic disease caused by the Delta mutation, the Moderna vaccine 72% and the AstraZeneca vaccine 67%.
The scientists who took part in the study report that the findings lead to the conclusion that even one dose of the three vaccines provides substantial protection against the disturbing mutations. The two doses, they add, provide even greater protection.
The findings contradict the results of a study published Thursday in the New England Journal of Medicine
In it, researchers extracted data from the Public Health of England. They claim that the Pfizer vaccine is only 36% effective after one dose, while the AstraZeneca vaccine is 30% effective.
At the same time, the Canadian study shows that one dose of the three vaccines is very effective against the most serious disease that leads to hospitalization or death. In particular, a dose of Pfizer, Moderna and AstraZeneca vaccines was 78%, 96% and 88% effective in the Delta mutation, respectively.
Lower efficacy, just 48%, seems to provide a dose of AstraZeneca vaccine against symptomatic diseases caused by Beta (South African) and Gamma (Brazilian) mutations In contrast, the Pfizer vaccine appears to be 60% effective and the Moderna 77% .
Efficacy of Pfizer and AstraZeneca vaccines against Delta mutation in percentages
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