Macau Chief Executive Ho Iat-seng said he felt "no different" after receiving the Sinopharm Covid-19 vaccine as the enclave began immunizing its citizens yesterday.

The first batch of 100,000 mainland-made two-dose Sinopharm vaccines - chosen for the first phase of Macau's program that arrived on Saturday - can cover 50,000 people.

Vaccinations started for high-risk groups yesterday, including health-care workers and disciplinary officers.

Ho was the first Macanese to get the jab at Conde S Januario Hospital. He did not have adverse reactions to his first shot and said he felt "more or less the same as on any other working day."

He said he would get the second shot in less than four weeks by the end of the month, as he had to attend the "Two Sessions" of the National People's Congress and the Chinese People's Political Consultative Conference in Beijing on March 4 and 5.

Asked why Macau chose Sinopharm, Ho said the vaccines had been deemed suitable for those above 60 who are in good health, as well as those between 18 and 60.

Ho, 63, also called on Macau citizens to get vaccinated on a voluntary basis for the sake of their health.

"There will also be another brand of vaccines arriving in Macau at the end of this month citizens can choose the brand they want later."

Macau rolled out vaccinations from 9am yesterday, with medical workers, police, firemen and customs officers among those receiving the shot.

Vaccinations are available to three prioritized groups, including frontline government workers and those who inevitably have to travel to high-risk areas.

People working in high-risk sectors, such as frozen and fresh food handlers, care home staff, transport workers, teachers, croupiers and government security officers, are also covered.

Tam, a supervisor working at Macau's customs, was among dozens who queued for the first jab at Conde S Januario's emergency room yesterday morning.

"My work involves contacting cold chain logistics, so there is a health risk," she said.

The next stage of vaccination, to start on February 22, will be open to other Macau residents.

The jab will be free for all residents, non-local employees with work permits, students and prisoners. It will cost 250 patacas (HK$242) for non-residents.

Separately, Hong Kong Chief Executive Carrie Lam Cheng Yuet-ngor denied the allegation that the SAR government lowered the thresholds to approve Sinovac vaccines.

The government will assess the effectiveness of the vaccine based on clinical phase III trial data that the vaccine manufacturer has passed on to a mainland regulator, instead of clinical studies published in journals - one of the criteria previously set by authorities for approval. Sinovac has yet to publish its clinical trial results in a medical peer-reviewed journal.

"I call upon citizens to make objective, scientific judgments on vaccines. Don't act like a small group of people who introduced political elements to affect people's willingness to get vaccinated," she said.

Ho Iat-seng said he felt no different after receiving the jab.

Macau begins rollout of Sinopharm vaccines