What Mosialos says about the Russian vaccine

The preliminary positive results of the tests of the Russian vaccine Sputnik V, which were published in the medical journal Lancet, commented in a post on Facebook, Elias Mosialos.

The LSE Professor of Health Policy states that the Russian vaccine actually consists of two components: both are based on the common cold viruses, adenovirus 5 and adenovirus 26.

“The Russian researchers used this approach because after vaccination the body can develop antibodies against the vaccine vector (adenovirus),” he said.

Mr. Mosialos described the results as encouraging, but stressed that there was no guarantee that they would be verified in phase III.

“No vaccine had been approved – before the Russian one – with such a small sample of voluntary I / II clinical trials, and without the results of Phase III, a large number of volunteers and a general analysis of the results,” he concludes in a significative way.

The entire post of Elias Mosialos:

“Results of the I / II clinical trials of the Russian Sputnik-V vaccine

The results of the non-randomized clinical trial I / II of the Russian Sputnik-V vaccine, which was tested in 76 healthy adult volunteers, men and women, aged 18 to 60 years (DOI: https://doi.org/), were published today in the Lancet. 10.1016 / S0140-6736 (20) 31866-3).

As I mentioned, the Russian vaccine actually consists of 2 components. Both are based on the common cold viruses, adenovirus 5 and adenovirus 26. This approach is similar to other COVID-19 vaccines (for example, the Chinese vaccine from CanSino Biologics Inc. is based on adenovirus 5 while Johnson & Johnson uses adenovirus 26 and no serious side effects have occurred). Russian researchers have used this approach because after vaccination, the body can develop antibodies against the vaccine vector (the adenoma). Therefore, a second booster dose with the virus carrier may be useless. Two-step vaccination with 2 different adenoviruses can avoid this problem.

According to the publication, in Phase I, one dose of adenovirus 5 or one dose of adenovirus 26 was administered intramuscularly on day 0 and the safety of the two components was evaluated separately for 28 days. In phase 2, which started no later than 5 days after the phase 1 vaccination, they were administered intramuscularly and the double / booster vaccine was tested. That is, the adenovirus 26 vaccine dose was administered on day 0 and the adenovirus 26 dose was administered on day 2 (the figure shows the design of the clinical trials).

The volunteers who received the vaccine had mild to moderate side effects, and the results are encouraging.

But, as in all clinical trials, there is no guarantee that they will be verified in phase III. As I have repeatedly stressed, it is phase III that determines whether vaccines actually protect people from infection and whether they are effective. Clinical trials in large numbers of people also allow researchers to detect rare side effects that may not occur in smaller studies. That is, if a side effect from the vaccine has an incidence of 1 in 1000 people, it obviously will not occur in a study of 80 people.

“No vaccine had been approved – before the Russian one – with such a small sample of voluntary I / II clinical trials, and without the results of Phase III, a large number of volunteers and a general analysis of the results.”