Phase III clinical trials for Russia’s Sputnik V vaccine for COVID-19 began Wednesday, one day after the Russia Direct Investment Fund (RDIF) launched a new website to share the details of the vaccine with the public and scientists around the world.
Phase III clinical trials for Russia’s Sputnik V vaccine for COVID-19 began Wednesday, one day after the Russia Direct Investment Fund (RDIF) launched a new website to share the details of the vaccine with the public and scientists around the world.
“The website is aimed at ensuring maximum transparency regarding the vaccine…and further results of its trials and use,” Kirill Dmitriev, RDIF CEO, said in a statement. It is a direct response to complaints of a lack of transparency from other nations’ scientists and health officials. Dmitriev, speaking in Russia’s defense August 12 on Russia Today, argued that, “Western media outlets blocked access to our information,” and failed to include key details of the virus in their coverage. Therefore, RDIF is going directly to the public and to scientists.
According to the website, Sputnik V is a two-vector vaccine against SARS-CoV-2. It requires an initial injection and a booster shot 21 days later to confer one- to two-year immunity.
The Russian vaccine uses the adenovirus vectors rAd26 and rAd5. Dmitriev said he believes Russia is the only nation to use these two vectors together. Several organizations are using either vector alone, however. Johnson & Johnson, for example, is using adenovirus Ad26, and China’s CanSino is using adenovirus Ad5 in COVID-19 vaccines.
Vector technology is well-established. To make the vectors, the disease-causing gene from the adenovirus is removed while a gene with the code of a protein from another virus – in this case, the S protein of the SARS-CoV-2 virus – is inserted.
Russian scientists have been developing a two-vector approach since 2015. Dmitriev explained the rational recently in what he called The Forbidden Op-Ed:
By using two adenoviral vectors, he wrote, “In this way, they trick the body, which has developed immunity against the first type of vector, and boost the effect of the vaccine with the second shot using a different vector. It is like two trains trying to deliver an important cargo to a fortress of a human body which needs the delivery in order to start producing antibodies. You need the second train to make sure the cargo reaches its destination. The second train should be different from the first one, which already came under attack from the body’s immune system and is already familiar to it. So, while other vaccine makers have only one train, we have two.”
This is the same approach – but with one different vector – that the Gamaleya National Research Institute of Epidemiology and Microbiology used for its Ebola vaccine in 2017/18.
“The two-vector approach will provide stronger immune responses,” Dmitriev said on RT. “We believe the immune response will last, hopefully, more than one year. Our scientists believe it will be two years.”
Sputnik V’s Phase III clinical trials just began vaccinating more than 2,000 people in Russia and additional populations in Brazil, Mexico, the United Arab Emirates and Saudi Arabia. “The vaccine has received a registration certificate from the Russian Ministry of Heath,” which allows vaccinations in Russia. The registration is considered similar to the FDA’s emergency use authorizations for COVID-19.
A Phase I/II trial was completed August 1. “All participants…developed a 100 percent immunity to COVID-19,” Dmitriev wrote.
Results of the Phase I/II study “will be published this month, in line with international requirements,” according to the RDIF. Where the data will be published was not mentioned. The paper is expected to include detailed information about the vaccine, including the exact number of antibodies generated (determined by third-party testing and also by the Gamaleya Center, which holds the vaccine patent).
That trial was designed to determine the antigen-specific antibody titer in blood serum (compared to baseline) 14, 21, 28 and 42 days after vaccination and to determine the virus neutralizing antibody titer at days 14, 28 and 42. It also assessed the antigen-specific cellular immunity (T cell immunity) at days 14 and 28. Participants were divided into two groups. The first, an 18-patient group, received one injection. The second, a 20-person cohort, also received a booster vaccination at day 21.
The Sputnik V website said that no deleterious side effects were observed.
“The high efficacy of the vaccine was confirmed by high precision tests for antibodies in the blood serum of volunteers (including an analysis for antibodies that neutralize the coronavirus), as well as the ability of the immune cells of the volunteers to activate in response to the spike S protein of the coronavirus, which indicates the formation of both antibody and cellular immune vaccine response.”
According to Dmitriev, “All the humans showed very strong immune responses. I’m confident enough to have injected the vaccine into myself, my wife, and my 84-year-old parents.”
