(Bloomberg) -- Russian President Vladimir Putin said Wednesday he took an experimental nasal Covid-19 vaccine earlier this week, a day after getting a booster injection of the locally developed Sputnik Light inoculation.

The nasal version is still in trials and hasn’t been approved by regulators. Sunday, in a televised appearance announcing he’d taken the injected booster, Putin said he would volunteer to participate in the testing of the nasal vaccine, as well. That option provides better protection in the upper respiratory tract against breakthrough infections than injected versions, Denis Logunov, deputy director of the Gamaleya National Research Center, Sputnik’s developer, told Putin.

The Russian president, 69, said Logunov gave him the nasal version Monday. Putin told a government meeting that he’s “feeling fine” after the boosters and had exercised today. 

Russia claimed to be the first to approve a Covid vaccine in the summer of 2020, but officials and scientists began getting the shots even before Sputnik was registered. Putin, however, got his first two-dose inoculation only in March of this year.

‘That’s Off-Label’

Gamaleya’s Logunov told the president that workers at the center had also tried the nasal version. “That’s off-label and we’re testing it on staff as usual,” he said.

In the meeting with Putin Wednesday, Prime Minister Mikhail Mishustin said pre-clinical testing of the nasal inoculation “showed it was safe and effective” and phase 1 clinical trials in adult volunteers have been authorized. Initial results are due in about 42 days.

At the same session, Putin again appealed to Russians to get vaccinated but said the government doesn’t plan to make the inoculations mandatory even though only about 40% of the population has gotten them. Officials said the government plans to register Sputnik for children aged 12-17 Wednesday.

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