The Russian vaccine against COVID-19 , Sputnik V, produced antibodies in volunteers injected with it, without prompting any adverse effects. The findings of the vaccine’s Phase 1 and 2 human trials were published in the journal The Lancet on 4 September.
On 11 August, Russian President Vladimir Putin announced that his country was the first to approve a vaccine offering “sustainable immunity” against the new coronavirus , leaving experts clamouring for results from trials of the vaccine. While the bulk of the reservations from health experts came from the US and the UK, there were voices of distrust from within Russia.
On 12 August, the World Health Organisation (WHO) said that it will review the data from the studies before giving its stamp of approval for human use of the vaccine. Recently, 32 researchers that took part in the clinical trials published findings from early, human trials to test its safety.
Two vectors, two shots
The Sputnik V vaccine is being developed by Gamaleya Scientific Research Institute of Epidemiology and Microbiology along with the Russian Defence Ministry and the Russian Direct Investment Fund (RDIF) has bankrolled the project.
Sputnik V uses a combination of two viral vectors adapted from the common cold-causing adenovirus, for pharmaceutical use – the adenovirus type 26 (rAd26) vector and a recombinant adenovirus type 5 (rAd5) vector. The vector carries the genetic code of the “spike” protein, which is spread across the surface of the COVID-19 -causing SARS-CoV-2 virus. This code acts like a tag for the immune system to recognize the virus if a genuine infection by the coronavirus comes along.
In phase 1 of each trial, individual components of the two-part vaccine (rAd26-S & rAd5-S) were tested for safety
Phase 2 tested whether the vaccine elicited an immune response by giving the full two-part vaccine – rAd26-S was given first, then rAd5-S was given 21 d later (4/8)
— The Lancet (@TheLancet) September 4, 2020
According to a statement by the RDIF, the use of two different vectors in two separate shots achieves a more effective immune response, as compared to the use of the same vector in two shots. By using the same vector twice, the immune system launches a defence mechanism against the virus and starts to reject the drug in the second injection,
The vaccine can be given to a person in two ways – frozen or lyophilised – is the process of freeze-drying a vaccine to make it more convenient to transfer and increase its shelf life. It is administered via an intramuscular injection – which is a technique used to deliver the vaccine deep into the muscles, allowing it to be absorbed into the bloodstream quickly.
Phase 1 and 2 completed
As of 1 August, Phase 1 and 2 clinical trials of the Gam-COVID-Vac Lyo were complete, as per a TASS report, in adult male and female volunteers between the ages of 18–60 years.
Early trials of the vaccine began on 18 June in a group of 18 volunteers. In this Phase 1 study, nine volunteers were given one dose of rAd26-S and the other nine were given a dose of rAd5-S. This was done to determine that both the adenovirus vector constructs were safe to use in people.
This was soon followed by second-stage trials in 20 volunteers, who were given shots of a ‘prime-boost vaccination’ with rAd26-S on day 0 (23 June), and rAd5-S 21 days later.
The research team, led by Denis Y Logunov who is the principal investigator of the study, found that the vaccine provides antibodies immunity (stable humoral and cellular immune response) and had no adverse reactions on any of the volunteers it was administered to.
The most common adverse events reported in the study were pain at the injection site, hyperthermia, headache, asthenia and muscle and joint pain. That said, most of these adverse events were mild, with no serious adverse events reported, which is an encouraging sign.
According to a statement by the RDIF, the level of antibodies in the volunteers vaccinated was 1.4-1.5 times higher than those in patients who had recovered from COVID-19 . In contrast, AstraZeneca-Oxford found that the volunteers participating in its clinical trials had antibodies virtually equal to that of those who had recovered from the infection.
There were concerns that by using the virus of the common cold, the resulting vaccine would not be that effective and that people will have preexisting immunity towards the adenoviruses. Researchers from the institute via this study have proved otherwise. The statement by RDIF said that the study has also determined the optimal dosage that is safe and will allow for an ‘effective immune response in 100 percent of those vaccinated, even in those who have recently had a common cold.’
What critics are saying
As per a recent report in the New York Times, even if the vaccine were modestly effective, there’s no research to show whether those given the vaccine were less likely to become infected than those who are not. This is an observation commonly made in Phase 3 trials.
Naor Bar-Zeev and Tom Inglesby from Johns Hopkins Bloomberg School of Public Health critiqued, in a commentary in The Lancet, that the vaccine was given to “young military personnel” who are likely to be “fitter and healthier than the general population.” They also point to the ethnicity of the people who took part in the trials, implying a lack of diversity for the vaccine to be considered safe to test in a larger population.
In a Comment, @naorbz & @T_Inglesby describe the studies as “encouraging but small. The immunogenicity bodes well, although nothing can be inferred on immunogenicity in older age groups & clinical efficacy for any #COVID19 vaccine has not yet been shown” https://t.co/nYQ6QfqccD pic.twitter.com/0RttILQVF9
— The Lancet (@TheLancet) September 4, 2020
However, Bar-Zeev also told The New York Times, “The science looks like it was done impeccably well” but larger trials need to be completed before we know if it is effective.
Enrico Bucci, a biochemistry and microbiology expert at Temple University, US has written an open letter to the editor of The Lancet claiming inconsistencies in the data and figures that are part of the Russian vaccine study. At last count, 26 other scientists have also signed the letter agreeing with Bucci. They believe that ‘several data patterns’ appear repeatedly in the experiments.
“The data looks like it’s been photoshopped … it’s too similar and too unlikely from a statistical point of view,” said Andrea Cossarizza, professor of pathology and immunology at the University of Modena and one of the signatories to the letter while speaking to The Moscow Times.
According to a report by The Print, The Lancet said in an emailed statement that they are aware of the letter and “encourage scientific debate on papers we have published… We have shared the letter directly with the authors and encouraged them to engage in the scientific discussion.”