(Bloomberg) -- China is studying if it’s necessary to give booster vaccine shots to vulnerable groups such as the elderly, people with underlying diseases and those who work in high-risk areas.

There isn’t yet enough evidence to suggest that it’s necessary to give a third shot to all people, Wang Huaqing, an expert with Chinese Center for Disease Control and Prevention, said at a press briefing Saturday.

The country recorded 328 new locally-transmitted coronavirus cases in July, almost equaling the amount of cases reported in the previous five months combined, National Health Commission spokesman Mi Feng said at the same briefing. The virus being transmitted currently is mostly the delta variant, but China’s virus control measures are still effective against it, Mi said.

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