The first results of Russia’s “Sputnik V” Covid-19 vaccine are in, concluding that the vaccine produces antibodies and has no noticeable side effects. That means so far, so good. But while the results are encouraging, independent experts are warning that the vaccine still needs further work before it is mass-produced and rolled out to the general population.
Reported in the journal The Lancet, the new study reports the findings of two non-randomized phase 1/2 trials on a total of 76 healthy people aged 18 to 60 that took place between June and early August at two hospitals in Moscow. The findings suggest there were no serious adverse effects after 42 days and the vaccine managed to spark antibody responses in all participants within 21 days.
Named Sputnik V as a homage to the world's first artificial Earth satellite launched by the Soviet Union in 1957, the vaccine is what’s known as a recombinant adenovirus vaccine. This means it uses harmless adenovirus, a group of common cold viruses, that has been tweaked to contain the spike protein of SARS-CoV-2, the virus that causes Covid-19. This gives the immune system the chance to recognize and respond to the virus, without the risk of getting sick.
“When adenovirus vaccines enter people’s cells, they deliver the SARS-CoV-2 spike protein genetic code, which causes cells to produce the spike protein. This helps teach the immune system to recognize and attack the SARS-CoV-2 virus,” Dr Denis Logunov, lead study author from the N F Gamaleya National Research Centre for Epidemiology and Microbiology in Russia, said in an emailed statement.
“To form a powerful immune response against SARS-CoV-2, it is important that a booster vaccination is provided. However, booster vaccinations that use the same adenovirus vector might not produce an effective response, because the immune system may recognize and attack the vector,” explained Dr Logunov. "This would block the vaccine from entering people’s cells and teaching the body to recognize and attack SARS-CoV-2. For our vaccine, we use two different adenovirus vectors in a bid to avoid the immune system becoming immune to the vector.”
The global race to find a viable coronavirus vaccine is well under away, but there are fears that scientists are being forced to rush development for the sake of national pride, geopolitical gain, and profit. President Vladimir Putin announced last month that the Russian vaccine was a “world-first” and that it had been approved for use by the regulators in Russia. He even claimed his daughter had received the vaccine.
Outside of Russia, however, there has been some skepticism. Dr Anthony Fauci, director of the US National Institute of Allergy and Infectious Diseases, said last month that he has “seriously doubt” Russia has definitively proven that the vaccine is safe and effective. This new study forces many to dispel some of these doubts, but scientists are still warning that further work should be have been carried out before receiving regulatory approval. First up, there’s no guarantee the immune response for the vaccine will be enough to evoke protection for Covid-19. Furthermore, the small number of participants means that some rarer side effects might not have been flagged up yet.
“Normally, such a study would be the basis for debating whether to proceed into larger trials and the costs that entails. In that context, the study results are encouraging in terms of safety and possible efficacy,” commented Dr Ohid Yaqub, a Senior Lecturer at the Science Policy Research Unit at the University of Sussex, who was not directly involved in the study. “However, in the context of regulatory approval, the design and size of a phase 1/2 study is not anywhere near sufficient for widely recognized standards of approval. The study was not randomized, and it was not large enough to detect rarer safety issues.”
However, these are promising steps in the right direction.