Recently, Pfizer announced 90% efficacy for its COVID-19 vaccine in phase 3 trials. Russia quickly responded, claiming 92% efficacy for its Sputnik V vaccine.
On November 9, 2020, Pfizer and BioNTech shared promising interim results from their ongoing phase 3 trials, showing 90% effectiveness against COVID-19 infections. The companies planned to seek emergency use authorization from the FDA as early as December 2020. Two days later, on November 11, Russia's Health Minister Mikhail Murashko highlighted Sputnik V's superior 92% efficacy via the official vaccine platform.
“Clinical trial results confirm Sputnik V as an effective tool to halt coronavirus spread, serving as a key preventive measure and the most reliable path to overcoming the pandemic,” Murashko stated.
Neither Pfizer nor Russia has released full peer-reviewed data—both announcements rely on press releases that warrant scrutiny. Russia's interim phase 3 results involve 40,000 volunteers in a double-blind trial across Belarus, the UAE, and Venezuela. However, only 16,000 received both doses three weeks apart. The 92% figure stems from just 20 confirmed COVID-19 cases, measured 21 days post-first dose versus placebo.
Pfizer's data covers 43,538 participants, with 38,955 completing the protocol. Efficacy analysis included 94 cases, evaluated one week after the second dose.
Prof. Stephen Evans of the London School of Hygiene & Tropical Medicine, via the UK Science Media Centre, noted the Sputnik V data's limitations due to low case numbers, suggesting possible overestimation—potentially closer to 60%. Pfizer's larger sample yields more reliable results, likely above 80%. Still, Sputnik V uses two modified adenoviruses, a proven platform requiring standard refrigeration, unlike Pfizer's -80°C needs.
Russia began distribution pre-final results, vaccinating 10,000 high-risk individuals and healthcare workers. Over 50 countries have ordered around 1.2 billion doses.
