BRUSSELS: Italian Prime Minister Mario Draghi said China's anti-COVID vaccine did not fully work and questioned whether Russia's Sputnik jab would ever get approval from European regulators.

"The Chinese vaccine ... has shown itself not to be adequate. You can see that from Chile's experience of tackling the epidemic," Draghi told reporters at the end of a European Union summit.

Chile has relied heavily on the COVID-19 shot developed by China's Sinovac, but health authorities in the South American country have questioned how effective it is against more transmissible virus variants and are also looking into how long it remains effective once injected.

A study published in April said the Chinese vaccine proved minimally effective at preventing illness after one dose. With a second jab, it was 67% effective in preventing symptomatic infection, 85% effective in preventing hospitalizations and 80% in preventing deaths.

Draghi also questioned Russia's Sputnik vaccine.

The European Medicines Agency (EMA) had been expected to conclude its review of the Russian jab and issue a decision in May or June. However, approval was delayed because the makers missed a June 10 deadline to submit data, sources told Reuters earlier this month.

"The Russian vaccine Sputnik has never been able to get approval from EMA and perhaps it never will," Draghi said.