Two Pfizer, AstraZeneca doses work towards Delta variant: research | Coronavirus pandemic Information

Two doses of Pfizer shot 88 percent effective in preventing the Delta variant, while two doses of AstraZeneca are 67 percent effective.

According to a new study, two doses of the COVID-19 vaccine from Pfizer or AstraZeneca are almost as effective against the highly transmittable delta coronavirus variant as it is against the previously dominant alpha variant.

Research published Wednesday in the New England Journal of Medicine showed that the vaccines against the Delta variant, which is now the world’s dominant strain, were highly effective, provided a person had received two vaccinations.

The study confirms Public Health England (PHE) headline results in May on the effectiveness of COVID-19 vaccines from Pfizer-BioNTech and Oxford-AstraZeneca based on real-world data.

Wednesday’s study found that Pfizer was 88 percent effective in preventing symptomatic disease with the Delta variant at both dosages, compared with 93.7 percent from the Alpha variant, essentially as previously reported.

Two shots of the AstraZeneca vaccine were 67 percent effective against the Delta variant, up from 60 percent originally reported and 74.5 percent effective against the Alpha variant, compared to an original estimate of 66 percent effectiveness.

“After receiving two doses of vaccine, the Delta variant showed only modest differences in vaccine effectiveness compared to the Alpha variant,” wrote researchers from Public Health England.

Data from Israel has estimated that Pfizer’s syringe is less effective against symptomatic illnesses, although protection against serious illnesses remains high.

PHE had previously said that the first dose of either vaccine was about 33 percent effective against symptomatic disorders of the Delta variant.

Other vaccines also useful

The full study published Wednesday found that one dose of Pfizer’s vaccine was 36 percent effective and one dose of AstraZeneca’s vaccine was about 30 percent effective.

“Our finding of decreased efficacy after the first dose would support efforts to maximize two-dose vaccine intake in vulnerable groups associated with the spread of the Delta variant,” the study authors said.

In June, the manufacturers of the Russian Sputnik vaccine also stated that it was around 90 percent effective against the highly contagious Delta variant [File: Leonardo Fernandez Viloria/Reuters]

Recently, researchers at Beth Israel Deaconess Medical Center in Boston, USA, also said that the antibody response from the unique Johnson & Johnson vaccine worked well against Delta in a laboratory setting, and that the immune response lasted for about eight months.

In June, the manufacturers of the Russian Sputnik vaccine also stated that it was around 90 percent effective against the highly contagious Delta variant.

The shot, which Russia is actively marketing overseas, was previously found by researchers to be nearly 92 percent effective against the original strain of the coronavirus.

Denis Logunov, the deputy director of Moscow’s Gamaleya Institute, which developed Sputnik, said the effectiveness number of the Delta variant was calculated based on digital medical and vaccine records, Russian state news agency RIA reported.

However, the Sputnik vaccine has caused some controversy as it was unveiled to the public before a full study was even completed. The approval from the World Health Organization is still pending.

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