President Xi Jinping on Monday said China faced a "new Covid situation," as he urged healthcare officials to take targeted measures to deal with the sudden surge in infections, the first time that he has spoken about the grim healthcare situation in the country.

In his fresh directive, Xi said that more targeted patriotic health campaigns should be conducted as the country's COVID-19 epidemic prevention and control faces new situations and new tasks.

As China continues to reel under a wave of Omicron variants, Xi demanded more efforts in guiding the public to acquire health knowledge and skills, maintain good personal hygiene and form a healthy lifestyle to build a defence line against the epidemic for the whole society, state-run Xinhua news agency reported on Monday.

This is the first time that the Chinese president has commented on the grim Covid situation in the country after his government overnight relaxed the stringent zero-covid policy earlier this month following mass anti-government protests.

Since then, cases stated to be variants of the Omicron have fuelled a spurt in infections across the country.

Premier Li Keqiang has called on governments at all levels to redouble their efforts, effectively ensure people's access to medical services, anti-epidemic supplies, and safeguard people's lives and health.

Amid reports of crematoriums working overtime and packed ICUs across several cities, the Chinese government reported only seven deaths, all in the capital city of Beijing.

A leaked document, purportedly from China's National Health Commission, said around 248 million, roughly 17.56 per cent of the total population were affected by the recent surge in infections from December 1 to 20.

Official media reports say that ICUs in Beijing are under stress as community transmission of the Omicron variant has led to increasingly severe cases -- most of whom are among the elderly -- in a short period of time.

Despite concerns, Beijing and Shanghai virtually returned to normalcy after several weeks with people thronging malls and eateries.

State-run Xinhua reported on Monday that a total of 13 types of COVID-19 vaccines, approved for conditional marketing or emergency use, are now available as the second booster shot in China.

Omicron-resistant vaccines are preferred in choosing second booster doses, it quoted experts.

As of Friday, more than 3.46 billion COVID-19 vaccine doses were administered on the Chinese mainland, with over 90 per cent of the population being fully vaccinated.

Population groups with a high risk of infections, especially people aged 60 and above, people with serious underlying health conditions and those with low immunity are advised to receive a second booster shot six months after the first, the report said.

Those who have received three doses of inactivated vaccines can choose a different type of vaccine -- recommended by the government -- for the second booster, namely a recombinant protein vaccine, an adenovirus vector vaccine or an influenza virus vector vaccine, according to experts.