Russia’s proposed coronavirus vaccine produced an antibody response in all participants without “serious adverse effects” during early-stage trials, according to results published Friday by The Lancet medical journal.
Moscow hailed the findings as an answer to critics who have expressed concerns about the safety and effectiveness of the so-called Sputnik-V vaccine, which President Vladimir Putin announced last month.
The results of the two trials — which were conducted this summer and involved 76 participants — showed 100 percent of them developing antibodies to COVID-19 with no serious side effects, according to The Lancet, Reuters reported.
Russia licensed the two-shot inoculation for domestic use in August before a large-scale trial had begun — the first country to do so and before any data had been published.
“The two 42-day trials — including 38 healthy adults each between the ages of 18 and 60 — did not find any serious adverse effects among participants, and confirmed that the vaccine candidates elicit an antibody response,” The Lancet said.
“Large, long-term trials including a placebo comparison, and further monitoring are needed to establish the long-term safety and effectiveness of the vaccine for preventing COVID-19 infection,” it added.
The Russian research suggested that the vaccine produced a response in a component of the immune system known as T cells, according to The Lancet.
The vaccine is given in two doses, with each based on a different vector that causes the common cold — human adenoviruses Ad5 and Ad26.
But some experts have said that using this delivery mechanism could make a vaccine less effective, since many people have already been exposed to and developed immunity to the adenovirus.
In the US and China, about 40 percent of people have high levels of antibodies from prior Ad5 exposure, according to Reuters.
Denis Logunov, one of Sputnik-V’s developers, told Reuters the vaccine uses a strong enough dose of Ad5 to overcome any prior immunity without compromising safety.
Some Western experts have warned against the use of Sputnik-V — an homage to the Soviet Union’s first orbital satellite in 1957 — until all internationally accepted testing and regulatory steps have been completed.
But with the results now published in an international, peer-reviewed journal, and after a 40,000-strong later-stage trial was launched last week, a senior Russian official took a victory lap Friday about Sputnik-V, which was created by the Moscow-based Gamaleya Institute.
“With this (publication) we answer all of the questions of the West that were diligently asked over the past three weeks, frankly with the clear goal of tarnishing the Russian vaccine,” said Kirill Dmitriev, head of the Russian Direct Investment Fund, which backed the vaccine.
“All of the boxes are checked,” he told Reuters. “Now … we will start asking questions of some of the Western vaccines.”
Dmitriev said at least 3,000 people had already been recruited for the large-scale trial, adding that initial results are expected in October or November.
Commenting on the early results, lead author Dr. Naor Bar-Zeev of the International Vaccine Access Center at the Johns Hopkins Bloomberg School of Public Health said the studies were “encouraging but small.”
Bar-Zeev — who was not involved in the study — told Reuters that “clinical efficacy for any COVID-19 vaccine has not yet been shown.”
More than half a dozen drugmakers are already conducting advanced clinical trials, including Moderna and Pfizer in the US.