The Lancet has published results of a study that saw Russia’s Covid-19 vaccine produce an antibody response in all participants.
Russia was criticized by a number of health experts for releasing and distributing their vaccine before Phase 3 trials were complete, but the latest development will be seen as vindication by the country.
The two trials were conducted in July and involved 76 patients, all of whom developed antibodies to the virus and exhibited no serious side effects. The two-shot job was approved for domestic use by Russian regulatory bodies in August, before any other country had considered doing so and before any results data had been published or a large-scale trial set underway.
“The two 42-day trials – including 38 healthy adults each – did not find any serious adverse effects among participants and confirmed that the vaccine candidates elicit an antibody response,” The Lancet, one of the world’s oldest and best-known medical journals, 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 continued.
Named Sputnik-V after the world’s first satellite, which was launched by the Soviet Union, the vaccine was criticized by many Western health experts and politicians alike. The results published by the Lancet will be seen as a victory by the Kremlin, but doubts are unlikely to be assuaged until results from the 40,000-person trial, launched last week, are released.
“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,” Kirill Dmitriev told Reuters.
“All of the boxes are checked,” said Dmitriev, who is the head of the Russian Direct Investment Fund (RDIF), Russia’s sovereign wealth fund, which has backed the vaccine. “Now… we will start asking questions of some of the Western vaccines.”
Dmitriev also highlighted how at least 3,000 people had already been signed up for the much larger trial of the Sputnik-V vaccine that was launched last week, and initial results were expected in October or November this year, likely before any country in the West has started to distribute a vaccine of their own.
“These findings of two open, phase 1/2 non-randomized studies of a heterologous prime-boost COVID-19 vaccine based on recombinant adenoviral vectors rAd26-S and rAd5-S show that the vaccine is safe, well tolerated, and induces strong humoral and cellular immune responses in 100% of healthy participants. All reported adverse events were mostly mild,” The Lancet said, in the discussion section of the results.
“The most common systemic and local reactions were pain at the injection site, hyperthermia (body temperature 37–38°C), headache, asthenia, and muscle and joint pain, which are typical for vaccines based on recombinant viral vectors. No serious adverse events were reported during the study. In general, the adverse event profile did not differ from those reported in published work for other vector-based vaccines.
“The incidence of adverse events in our studies was slightly lower than in other work; a comparative clinical study with other vaccines is needed to confirm these findings,” the journal continued, giving hope that the vaccine will prove to be successful and no risk to the Russian public.
“In preclinical studies of the vaccine (unpublished data), robust humoral and cellular immune responses were elicited in non-human primates, providing protection from SARS-CoV-2 infection. The vaccine showed 100% protectivity in a lethal model of SARS-CoV-2 challenge in immunosuppressed hamsters. No antibody-dependent enhancement of infection was seen in vaccinated and SARS-CoV-2-challenged animals.
“Limitations of our studies include the short duration of follow-up (42 days), inclusion of only male volunteers in some parts of phase 1, the low number of participants (n=76), and no placebo or control vaccine. Despite planning to recruit healthy volunteers aged 18–60 years, in general, our study included fairly young volunteers,” The Lancet said, highlighting that the results found were far from conclusive and that much more data is needed to get a clearer overall indication of the vaccine’s efficacy and its potential risks.
“Further research is needed to evaluate the vaccine in different populations, including older age groups, individuals with underlying medical conditions, and people in at-risk groups. Participants in these phase 1/2 trials will be followed up to 180 days after initial immunization.
“In conclusion, these data collectively show that the heterologous vaccine based on rAd26-S and rAd5-S is safe, well tolerated, and does not cause serious adverse events in healthy adult volunteers. The vaccine is highly immunogenic and induces strong humoral and cellular immune responses in 100% of healthy adult volunteers, with antibody titres in vaccinated participants higher than those in convalescent plasma.
“Unprecedented measures have been taken to develop a COVID-19 vaccine in Russia. Based on our own experience in developing vaccines against Ebola virus disease and MERS, the COVID-19 vaccine has been developed in a short time.”