Just a few days after the German pharmaceutical company Pfizer announced preliminary results from its Phase 3 trials for a vaccine against coronavirus, the Russian Direct Investment Fund (RDIF) issued its own announcement that Sputnik V, the world’s first registered vaccine against Covid-19, has shown results even better than those claimed by Pfizer.
Sputnik V was registered on August 11, before Phase 3 trials began on August 25, and over 50 countries have already placed orders for the vaccine. Criticism that the vaccine was already being marketed after the completion of Phase 2 trials was fierce, even after the publication of an article in the Lancet medical journal concluding that it appeared safe and reasonably effective so far, but at this point in time, many governments seem to have concluded that it is wise to place their orders now, even based solely on preliminary results, as many have done with Pfizer’s product.
Like Pfizer, Sputnik V was and is still being tested in a double-blind randomized placebo-controlled trial. 40,000 volunteers have been registered, divided among 29 medical centers, and the interim results relate to around 16,000 of them who received two doses of either vaccine or placebo, 21 days apart. Among the preliminary cohort 20 virus cases were reported with claims of a 92% efficacy rate. Since the complete data has not been released (as is the case with Pfizer as well), it can only be guessed what 92% actually means; most simplistically, it means that of the 20 virus cases, (around) 18 received placebo and 2 the vaccine.
In addition, Sputnik V apparently produced “no unexpected adverse events” other than the usual side effects to most vaccines i.e. short-term pain at the injection site, and flu-like symptoms.
RDIF also noted in its press release that another trial, conducted in September and involving over 10,000 participants, showed a similar efficacy rate of over 90%. Phase 3 trials are set to continue for the next six months, during which all volunteers will be kept under observation, and at the conclusion of that time period, the full clinical trial report will be released.
As with Pfizer’s product, the data do not differentiate between trial subjects based on age. However, RDIF is concurrently conducting a separate study focusing solely on the elderly.
Responding to RDIF’s press release on Wednesday, Russian Health Minister Mikhail Murashko stated: “The results of clinical trials demonstrate that it is an efficient solution to stop the spread of coronavirus infection, а preventive healthcare tool, and this is the most successful path to defeat the pandemic.”
Kirill Dmitriev, CEO of the RDIF, noted that, “The vaccine is based on safe and effective platform of human adenoviral vectors … I would also like to stress the importance of international cooperation and close partnership among vaccine-developing states. Vaccines should be above politics. The world needs a diversified portfolio of high-quality vaccines with Sputnik V, based on the well-tested human adenoviral vector platform, being an important element of it.”
Scientists from abroad have responded with optimism to the news, with Prof. Ian Jones of the University of Reading stating that: “Sputnik data is yet more good news for Covid-19 vaccine development.”
He pointed out that, “Although based on fewer cases than the recent Pfizer data, the vaccine looks as efficient … [however], we still need to know about the longevity of the response and the efficiency in different age groups.”
Prof. Paul Hunter of UEA noted that since the Sputnik V vaccine is based on an attenuated adenovirus, “it is more stable … than the [Pfizer] mRNA vaccine,” which has to be stored at minus 80 degrees Celsius. Sputnik V, by contrast, is in freeze-dried form, making distribution far simpler. In addition, vaccines based on attenuated adenoviruses have been around for decades already, making them more likely to be safe in the long-term, which is impossible to know with a newer form of vaccine.
Noting that neither Pfizer nor RDIF are claiming to have tested for asymptomatic cases, Dr. Stephen Griffin of the University of Leeds was more cautious in his response. “We will have to learn whether these [vaccines] prevent infection itself or just severe symptoms,” he noted, “as well as if vaccinees might continue shedding infectious virus [even when asymptomatic]. In addition, efficacy in different age groups, ethnicities and in patients with compromised immune systems will need to be determined before we can decide how best to deploy these hopefully world-changing medicines.”
In Russia itself, confidence in Sputnik V – and indeed, in any vaccine for coronavirus – is not high, ranging around the 50% mark depending on when the poll was conducted. According to the Independent, a program to market vaccine doses to essential workers such as doctors and teachers led to many protests, with one teachers’ union starting an online petition urging its members to refuse to comply, and insisting that vaccination should not be compulsory until clinical trials are complete.