Tuesday, October 26

Sputnik V Vaccine 91.6% Efficacy Against Symptomatic Covid, Russian Trial Suggests | Society

The Russian Sputnik V vaccine is 91.6% effective against symptomatic coronavirus, results of interim trials have suggested.

The preliminary findings are based on data analysis from more than 20,000 mostly white participants, three-quarters of whom received the vaccine. The rest received a placebo.

Serious adverse events were not considered to be associated with vaccination and the majority of adverse events reported were mild, including flu-like symptoms, injection site pain, and weakness or low energy.

The vaccine, which is backed by the Russian Direct Investment Fund (RDIF), is given in two injections 21 days apart. In the 21 days after the first dose, there were 16 cases of Covid-19 in the 14,964 people (0.1%) in the vaccine group and 62 cases of the disease in the 4,902 people (1.3%) in the placebo group .

The trial included 2,144 participants aged 60 and over; in this subset, the vaccine was 91.8% effective against symptomatic disease, the researchers wrote in The Lancet magazine.

Similar to the Oxford / AstraZeneca vaccine, Sputnik V is based on a modified version of the adenovirus, a virus from the common cold. This is designed to carry genetic instructions for making the coronavirus spike protein, which is passed into human cells. The manufactured coronavirus spike protein triggers an immune response to again protect Covid-19 disease.

However, unlike the first, Sputnik V uses two different human adenoviruses to try to trigger a stronger, longer-term immune response. Using a different vector for the second dose is designed to decrease the risk of the immune system developing resistance to the initial vector.

This analysis includes only symptomatic Covid-19 cases, the researchers cautioned, noting that more research is required to understand the effects of the vaccine on asymptomatic Covid-19 and on transmission. Additionally, patients were followed up to 48 days after the first dose, so the durability of protection also remains to be seen.

Four deaths were reported during the trial. One person died in the placebo group due to a stroke, while the remaining three deaths occurred in the vaccine group, but were not attributed to the vaccine. One patient had a fracture, while the other two had underlying conditions and developed Covid-19 symptoms four to five after the first dose of the vaccine, indicating they had been infected prior to the trial, the researchers suggested.

Serious side effects were seen in 68 patients, 45 of whom were in the placebo group. None of these were attributed to the vaccine.

“This recent positive phase 3 trial … is very encouraging in terms of efficacy, lack of serious side effects and seemingly equivalent protection in older patients,” said Dr. Stephen Griffin, associate professor at the University of Medicine School. from Leeds.

This study was not designed to evaluate the efficacy of just the first dose, but when the researchers looked at the level of protection from day 15 to 21, the efficacy against moderate or severe Covid-19 was 73.6%, they said. The team plans to launch trials to test a one-dose regimen, dubbed Sputnik V light, in the coming weeks, said Kirill Dmitriev, executive director of RDIF.

Last month, plans were also announced to test a combination of the Oxford / AstraZeneca and Sputnik V vaccines.

The last-stage trial of Sputnik V is ongoing and aims to recruit at least 40,000 people. When Russia gave the vaccine regulatory go-ahead and rolled out mass vaccines before the data from the phase 3 trials were revealed, scientists expressed concern and lamented the lack of transparency.

“Russia was right all the time,” Dmitriev said Tuesday.


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