A medical worker shows an electronic bracelet for monitoring the health of volunteers who take part in the phase-3 clinical trials of COVID-19 vaccine named "Sputnik V" in Moscow, Russia, on Sept. 15, 2020. (Photo by Alexander Zemlianichenko Jr/Xinhua)

Photo taken on Sept. 15, 2020 shows Russia's new COVID-19 vaccine named "Sputnik V" during the phase-3 clinical trials in Moscow, Russia. (Photo by Alexander Zemlianichenko Jr/Xinhua)

A medical worker inoculates a volunteer with the COVID-19 vaccine named "Sputnik V" during the phase-3 clinical trials in Moscow, Russia, on Sept. 15, 2020. (Photo by Alexander Zemlianichenko Jr/Xinhua)

A medical worker takes COVID-19 vaccine named "Sputnik V" out of a fridge during the phase-3 clinical trials in Moscow, Russia, on Sept. 15, 2020. (Photo by Alexander Zemlianichenko Jr/Xinhua)

A medical worker checks the temperature of a volunteer before inoculating her with the new COVID-19 vaccine named "Sputnik V" during the phase-3 clinical trials in Moscow, Russia, on Sept. 15, 2020. (Photo by Alexander Zemlianichenko Jr/Xinhua)