Russia’s Sputnik V coronavirus vaccine offers strong protection against hospitalization, according to scientists who have conducted the first independent real-world study of the jab’s effectiveness in combating severe infections.
Scientists at a group of Russian universities found the vaccine was 81% effective in preventing hospitalization among people who had contracted a symptomatic Covid-19 infection.
The report, published Monday, is a pre-print, which means it has not yet been peer-reviewed.
Since the study only focused on those who had already caught Covid-19, the study’s authors concluded that the overall protection offered by Sputnik V against severe infections, including those caused by the Delta variant, will be “comparable” to the above-90% protection offered by other vaccines.
The study tracked outcomes for almost 14,000 patients who contracted Covid-19 in St. Petersburg between July 3-Aug. 9. It was led by Anton Barchuk, head of the Institute for Interdisciplinary Health Research at the European University in St. Petersburg, and eight other scientists from Russian universities.
Of the 12,154 patients who tested positive for Covid-19 in the study and were not vaccinated, some 467 were hospitalized — a ratio of 3.8%. Meanwhile just 17 of the 1,291 vaccinated patients who caught the infection — 1.3% — were hospitalized. After adjusting for age and sex, the scientists assessed the vaccine’s effectiveness at preventing hospitalizaiton among those who were infected with Covid-19 at 81%.
“When breakthrough infections are evolving as a cause of major concern, our data is assuring that the vaccine effect is going beyond the risk of contracting the infection. It shows that vaccination significantly diminishes disease severity and protects the lungs from virus-induced injury,” the scientists said in the paper.
The study did not sequence which variant of the coronavirus patients were infected with. It was conducted at a time when the Delta variant had already swept across Russia, and was accounting for more than 90% of all new infections in Moscow. Previous laboratory studies had shown Sputnik V offered a weaker immune response against Delta and other variants of concern.
The scientists also found limited protection of just 35% against hospitalization among partially-vaccinated patients, counted as those who have received just one dose of a vaccine at least 14 days prior to catching Covid-19.
They hope the research — which they say is the first independent real-world assessment of vaccine effectiveness in Russia — will support the country’s flagging vaccination campaign.
“The lack of real-world evidence on vaccine effectiveness became a public health issue in Russia,” the scientists noted.
“Vaccination uptake was undermined by vaccine hesitancy, partly driven by the lack of independent research exploring vaccine safety and effectiveness and failures to communicate the balance of benefits and harms of Covid-19 vaccination.”
Russia’s Health Ministry previously said Sputnik V is 83% effective against contracting the Delta variant. The jab’s developers have been criticized on numerous occasions over questionable claims as to the vaccine’s effectiveness and for blocking independent scientists’ and regulators’ attempts to access study data.
Only 24% of Russians are fully vaccinated against the coronavirus despite vaccines having been widely and freely available since the end of last year. Multiple polls have shown more than half of Russians do not plan to get vaccinated.