The global health crisis prompted an urgent demand for effective vaccines against the novel coronavirus. Among the earliest to emerge were vaccines developed in Russia, notably Sputnik V, also known as Gam-COVID-Vac. These vaccines gained considerable attention worldwide due to their early registration and deployment in various countries, marking a significant moment in the international effort to combat the viral infection.
How Russian Vaccines Work
Russian vaccines employ diverse scientific approaches to stimulate an immune response. Sputnik V, the most widely recognized, is an adenoviral vector vaccine. It uses modified versions of adenoviruses, which typically cause common cold symptoms, as carriers to deliver genetic instructions. Specifically, Sputnik V utilizes two different human adenoviruses, adenovirus type 26 (Ad26) for the first dose and adenovirus type 5 (Ad5) for the second dose, given approximately 21 days apart.
These adenoviruses are engineered to carry the gene encoding the spike (S) protein of the SARS-CoV-2 virus. Once administered, the viral vectors enter human cells, prompting them to produce the spike protein. The body’s immune system then recognizes this protein as foreign and begins to generate antibodies and T-cells, preparing to fight off a future infection by the actual virus. The use of two different adenovirus vectors for the prime and boost doses in Sputnik V is a strategy designed to reduce the risk of the immune system developing resistance to the vector itself, potentially enhancing the overall immune response.
Beyond Sputnik V, Russia also developed other vaccines, including EpiVacCorona and CoviVac. EpiVacCorona is a peptide-based vaccine, which means it uses synthetic peptide fragments that mimic parts of the SARS-CoV-2 spike protein. These peptides are conjugated to a carrier protein and adsorbed onto an aluminum-containing adjuvant to enhance the immune response. CoviVac, on the other hand, is an inactivated whole-virion vaccine, a more traditional vaccine technology. It contains whole SARS-CoV-2 virus particles that have been chemically inactivated so they cannot cause disease but can still trigger an immune response.
Effectiveness and Safety Data
An interim analysis of Sputnik V’s Phase 3 clinical trial, published in The Lancet, indicated an efficacy of 91.6% against symptomatic COVID-19. This analysis was based on data from nearly 20,000 participants. The study also reported 100% effectiveness against moderate or severe COVID-19 cases 21 days after the first dose. For participants over 60 years old, the vaccine efficacy was reported at 91.8%.
Real-world data from various countries also provided insights into Sputnik V’s performance. In Bahrain, the vaccine showed protection against laboratory-confirmed infection and hospitalization. Observations in Russia during the Delta variant surge indicated an effectiveness of 80%. A study during the Omicron variant dominance in Moscow found an effectiveness of 85.9% against hospitalization for those who received more than one dose.
Regarding safety, common side effects reported in trials and real-world use were generally mild, including fever, headache, body pain, and injection site pain. These reactions were more frequently observed after the second dose. The Gamaleya Institute stated that Sputnik V’s efficacy has been documented in over 50 real-world and scientific studies across 10 countries, involving more than 12 million people.
International Use and Approval
Sputnik V has received emergency use authorization or registration in numerous countries globally. By April 2021, 62 countries had granted emergency use authorization, including India on April 12, 2021. Belarus and Argentina were among the first foreign countries to register the vaccine in December 2020. Hungary became the first European Union country to register Sputnik V for emergency use in January 2021.
Despite its widespread international adoption, Sputnik V has faced challenges in gaining approval from major regulatory bodies like the World Health Organization (WHO) and the European Medicines Agency (EMA). The WHO has been reviewing data from Sputnik V but has stated that the Emergency Use Listing process was on hold due to missing data and legal procedures. This lack of WHO recognition has implications for the vaccine’s inclusion in global initiatives like COVAX and can affect international travel for individuals vaccinated with Sputnik V. The EMA began an expedited approval process for Sputnik V in March, with experts visiting manufacturing sites, but has also stated that it is awaiting additional data.
Common Questions and Perceptions
Initial perceptions surrounding Sputnik V were marked by skepticism, largely due to its early registration in Russia before the publication of comprehensive Phase 3 trial data. This led to questions from experts worldwide regarding its safety and efficacy. However, the publication of the interim Phase 3 results in The Lancet in February 2021 helped to address some of these transparency concerns, with independent experts acknowledging the vaccine’s demonstrated scientific principle.
The scientific community’s understanding evolved as more data became available, though some researchers continued to raise concerns about the statistical consistency of the published efficacy data. Despite these discussions, the Gamaleya Institute emphasized that real-world studies in various countries support the vaccine’s effectiveness. Public perception in some regions, such as India, indicated high vaccine coverage and awareness of side effects, with many taking the vaccine due to its protective role and availability.
Concerns about vaccine hesitancy were also observed, with some surveys in Russia indicating that a significant portion of the population doubted its effectiveness or considered it not sufficiently studied. These perceptions highlighted the importance of clear communication and the role of healthcare workers in providing information to foster vaccine acceptance.