Scientists find out which vaccine is more effective against a new strain of COVID
It has also become known that the Indian variant reduces the effectiveness of all vaccines.
The Indian strain COVID-19, which has been named variant Delta, continues to spread worldwide, including in Canada. Scientists investigated whether existing vaccines are effective against this variant.
The medical journal The Lancet published a study that examined 19,543 cases of COVID-19 and 377 hospitalizations. Of these, 7,723 people had the Delta variant and 134 hospitalizations were associated with it.
According to the results, the effect of vaccination does not appear until 28 days after the first vaccination.
After 14 days of two doses, Pfizer's drug showed 92% efficacy against the Alpha variant, which was first detected in the UK, and 79% against the Delta variant, which was first detected in India. AstraZeneca's vaccine, in turn, showed efficacy of 73% and 60%, respectively. Researchers found that both Pfizer and AstraZeneca reduced the risk of severe disease in Delta, but both vaccines against this strain were less effective than the others.
Experts noted that both drugs protect against different strains of COVID-19, but the difference between them cannot be ignored.
According to Health Canada, the Delta variant now accounts for the majority of COVID-19 cases in the country. This strain has even threatened plans to lift restrictions in Canada and around the world. Moreover, when people are infected with variant Delta, the risk of hospitalization increases, especially for those who suffer from multiple chronic illnesses.
Despite the findings, the researchers urge people not to rate the drugs or compare their effectiveness. In addition, another study, already conducted in the UK, found that two doses of any vaccine were more than 90% effective in preventing severe disease and subsequent hospitalization.
