In a globally significant move, Russia has become the inaugural country to officially register a Covid-19 vaccine, announcing its readiness for use. The vaccine, coined Sputnik V and named after the Soviet Union’s first artificial earth satellite, Sputnik-I, is currently in the lead against various other Covid-19 vaccines in development, outpacing Oxford-AstraZeneca, Moderna, and Pfizer, all of which are still in trial stages.
The Sputnik V Vaccine: Adenovirus Vector-Based
Sputnik V, an adenovirus vector vaccine, was established through the collaborative efforts of Moscow’s Gamaleya Institute and Russia’s defense ministry. The Chinese vaccine had been given approval for ‘limited use’ prior to this, but it was only permitted to be administered to members of the People’s Liberation Army. The design of the Sputnik V vaccine utilizes the DNA of a SARS-CoV-2 type adenovirus, a familiar virus causing the common cold. The vaccine uses the weakened virus to deliver fragments of the pathogen to stimulate an immune response. It is provided in two doses, each comprising of two types of human adenovirus carrying an S-antigen of the new coronavirus. These viral components enter human cells, triggering an immune response.
Russian authorities have indicated that mass production of the vaccine could commence by September, with potential for a large-scale vaccination campaign as early as October.
What is an Adenovirus Vector Vaccine?
An adenovirus vector vaccine employs adenovirus as a tool to deliver genes or vaccine antigens to the target host tissue. Adenoviruses are DNA viruses whose size ranges from 70-90 nanometers, capable of causing illnesses such as the common cold and respiratory infections in humans. Adenoviruses are chosen for vaccines because their double-stranded DNA makes them more genetically stable, reducing the likelihood of genetic alterations post-injection.
The Concerns Surrounding the Vaccine
Despite the advances made with Sputnik V, several experts have voiced concerns regarding the safety and efficacy of the vaccine due to its rapid development and lack of published data. The public has been privy only to results from phase-I of clinical trials, which Russian authorities claim were successful. Given that these types of human trials often take several years under normal circumstances, the completion of such trials for Sputnik V in less than two months has raised eyebrows. Late-phase human trials are particularly critical as the vaccine’s efficacy can vary across population groups.
India’s Relationship with Sputnik V
Many countries, including India, have expressed interest in Sputnik V. Despite having an existing partnership with the USA for Covid-19 vaccine development, India’s approval for any vaccine would still need to be granted by the Central Drugs Standard Control Organisation (CDSCO). This National Regulatory Authority (NRA) organization has the authority to request Russia to conduct late-phase human trials on an Indian population or issue emergency authorization without such trials. However, the latter is seen as unlikely due to the potential risks involved in vaccinating large numbers of people.
The Development Process of a Vaccine
The general stages of the development cycle of a vaccine include the exploratory stage, pre-clinical stage, clinical development, regulatory review, and approval, followed by manufacturing and quality control. The clinical development process is typically divided into three phases: phase I, phase II, and phase III, each having a unique focus and involving varying numbers of subjects. Russia claims that the speedy development of Sputnik V was possible because it closely resembled a vaccine for Middle East Respiratory Syndrome (MERS), which had already undergone extensive testing.
The Way Forward
While the creation of the Russian Vaccine is a significant step in the fight against Covid-19, there remain concerns about its efficacy and safety. These must be prioritized by the developers as they continue to advance in manufacturing and distribution processes to ensure the vaccine can be effectively administered on a large scale.
