On Tuesday (August 11), the Russian government cleared the world’s first Covid-19 vaccine for public use.
The vaccine has been named Sputnik V, in honour of another world first, the Sputnik satellite launched by the Soviet Union in 1957, during the Cold War.
Full-scale production of the vaccine is expected to begin in September. It is being developed by Moscow’s Gamaleya Institute, the Defence Ministry and the sovereign Russian Direct Investment Fund.
To be sure, the green light didn't come as surprise, as Russian officials have been hinting at possible approval of the vaccine for the past few weeks.
What exactly is Sputnik V?
The Sputnik V vaccine comes under a category of non-replicating viral vectors. A vector, in this instance, is a weakened virus that transports pieces of disease-causing pathogen in an attempt to stimulate an immune response. Sputnik V is based on a modified human adenovirus as vector, which carries the protein of the SARS-CoV-2 virus.
Adenoviruses are benign and relatively easier to engineer, and have therefore become very popular as vectors.
However, not a single vaccine has been approved until now for commercial use involving this vector. There are several potential vaccines now being developed using adenoviruses, including the leading candidates by Oxford University-AstraZeneca vaccine, China’s CanSino Biologics and Johnson & Johnson.
In Sputnik's case, the infection-causing gene in the adenovirus is knocked off, and the SARS-CoV-2 Spike protein gene is inserted. Once re-engineered, the adenovirus is given to the body, and generates an immune response.
The vaccine has to be given in two doses, with a gap of 21 days. Interestingly, the Russians used two types of human adenoviruses (rAd26 and rAd5) for the first and second vaccination, to boost the effect of the vaccine.
China’s CanSino Biologics (Ad5) and Oxford University-AstraZeneca's Chimpanzee adenovirus (ChAdOx1) have used a single variant adenovirus.
How safe is the vaccine?
According to the WHO, the vaccine is in phase-1 clinical trials, with 76 participants.
The Russian government, however, says phase-1 and phase 2 clinical trials were completed on August 1. It says that all the volunteers are feeling well, and no unforeseen or unwanted side effects have been observed. It also claims that the vaccine induced a strong antibody and cellular immune response.
“Not a single participant of the current clinical trials got infected with Covid-19 after being administered with the vaccine,” claims the official website of the Russian vaccine.
Russian official sources say that the vaccine will begin phase-3 clinical trials involving more than 2,000 people in Russia, and a number of Middle Eastern countries such as the UAE and Saudi Arabia, and Latin American countries, including Brazil and Mexico. Russian officials say that India, too, has shown interest in becoming part of the phase-3 trial.
Mass production of the vaccine is expected to start next month.
What are the concerns over Sputnik V?
Russia is taking an enormous risk by going ahead with a vaccine that has not been tested rigorously on humans to ascertain its safety and efficacy. Vaccines, unlike drugs, are given to healthy individuals across age groups and gender.
Gamaleya is yet to publish results from human trials, or preclinical studies that involve testing on animals in any peer-reviewed journal. So, there isn't much data available on the vaccine's safety, efficacy and dosage.
Experts say that Phase-1 and Phase-2 trials are too small to establish safety and efficacy. Conventionally regulators take a call on approving a vaccine following phase-3.
Typically, phase-3 is conducted on 20,000-40,000 people, to find out whether the vaccine candidate can stop people from getting Covid-19 in the real world and how long the protection lasts.
It takes years to get this information in a natural setting, though the process can be sped up by using human challenge trials — where a vaccinated person is deliberately exposed to the virus. But there are ethical issues with this. Also phase-3 studies are designed carefully by enrolling people from different age groups, races and socioeconomic backgrounds.
Experts also say that it is difficult to predict which vaccine will be successful, as the vast majority in early development might fail. So, it's better to bet on several potential vaccines than on one vaccine.
Why India needs to be cautious
India is one of the 20 countries that has expressed interest to be part of Sputnik V’s Phase-3 clinical trials. In addition, the Russian Direct Investment Fund has stated that it is planning to start mass production in other countries, including India, in partnership with local sovereign wealth funds.
Russian President Vladmir Putin took a big gamble by going ahead with the vaccine. It would be tempting for countries such as India, Brazil, Mexico and others to follow Russia, as they struggle to contain the virus. A safe and effective vaccine is believed to be the quickest and surest way to achieve herd immunity.
An expert committee led by NITI Aayog member VK Paul will be meeting today to consider the logistics and ethical aspects of procuring and administering the potential vaccine. This is a hint that the Indian government may be considering its options and preparing the ground for an early approval.
India, however, may be better off waiting and watching Russia’s own experience with its vaccine.