Clinical Trials Combining AstraZeneca, Sputnik V Vaccines to Start Next Week

Trials evaluating the effectiveness of a combined regimen of the Gamaleya Research Institute’s Sputnik V vaccine and the AstraZeneca/University of Oxford vaccine are set to begin next week in Azerbaijan, the United Arab Emirates and other Middle Eastern nations.

The trials will test if the Sputnik V shot and the AZ/Oxford shot can offer improved efficacy when given as a two-dose regimen. Work has already gotten under way on the trials, with some beginning patient enrollment last week, and the Gamaleya Research Institute said it is open for Sputnik V collaborations with other COVID-19 vaccines.

Trials will reportedly also take place in Argentina, Belarus, Russia and the Ukraine, and the Russian Direct Investment Fund is expected to soon announce a collaborative trial with a large Chinese firm.

AstraZeneca first announced the Sputnik V collaboration in December, though it offered few details at the time, only noting that it was “considering how it can assess heterologous combinations of different vaccines … and will soon begin exploring with Gamaleya Research Institute in Russia to understand whether two adenovirus-based vaccines can be successfully combined.”

The new research comes amid strong showings from both two-dose viral-vector vaccines, which have demonstrated in late-stage trials to be highly effective and able to curb COVID-19 from progressing to serious infection. Notably, AstraZeneca’s vaccine was not only 82 percent effective after the second dose was given three months later but also appeared to cut the rates of viral transmission in participants by 67 percent, a quality that may prove to be a game-changer in the pandemic battle (DID, Feb. 4).

The Sputnik V vaccine dazzled the world this week when peer-reviewed interim results from a phase 3 trial showed it was safe and nearly 92 percent effective against symptomatic coronavirus (DID, Feb. 3). Skepticism and controversy previously surrounded the vaccine after Russia cleared it for emergency use before its late-stage trial had even started, drawing international criticism for authorizing it before critical data had been produced and evaluated.

The vaccine takes a “heterologous boosting” approach by using two doses with different vectors. Many vaccines work better if a different vaccine is used as a booster, according to Peter English, the immediate former chair of the British Medical Association Public Health Medicine Committee. English noted the hepatitis B vaccine, which has an improved effect in some patients given a heterologous booster, and development of an improved tuberculosis vaccine, which is trying out heterologous boosting to improve immunity. — James Miessler