Today, the results from an analysis of a large-scale clinical trial published in the British medical journal the Lancet showed that the Russian Sputnik V, two-shot vaccine was 91.6% effective in preventing symptomatic Covid-19 and offered complete protection against severe cases.
The paper also reported that there were no serious side effects and no deaths related to the vaccine. While not broken down by location, the vaccine was also equally safe and effective in people over the age of 65.
The vaccine is very different in formulation from the RNA vaccines by Moderna and Pfizer. Those vaccines use isolated genetic material coding for the coronavirus spike protein whereas the Russian vaccine uses a recombinant adenovirus that delivers the spike protein genetic material, similar to AstraZeneca and Johnson and Johnson. Uniquely, the Russian vaccine uses two shots, 21 days apart, each one containing different versions of adenovirus. It was hoped that using two different virus delivery systems (vectors) would prevent immunity to the vector from neutralizing the second, booster dose.
The Sputnik V efficacy is almost as good as the RNA vaccines, which are around 95% effective. The efficacy is much better than the two other adenovirus-based vaccines from AstraZeneca and Johnson and Johnson, which have published efficacy rates in the mid 60% range. This may be due to the two doses and the use of two different viral vectors. AstraZeneca’s vaccine is in trouble not just for having low efficacy, but also for having problems with manufacturing.
So far, Sputnik V has been administered to more than two million people world-wide, including individuals in Argentina, Serbia, and Algeria, according to Russian authorities. Some 15 countries outside Russia have already authorized Sputnik V, and it could be a real force for good in the developing world since it only needs standard refrigeration.
I commented when I first saw the Russian vaccine data in September that the vaccine looked promising despite being rushed through clinical trial. My expectations for the high quality of this vaccine turned out to be justified.