The government is considering administering a third dose to those who have received their second shot of vaccine against Covid-19 to boost their antibodies and determine how it can protect them from the new Delta coronavirus variant and its slightly mutated version Delta Plus, according to a senior health official.

York Sambath, the Ministry of Health secretary of state, said this while receiving another four million does of Covid-19 vaccines at Phnom Penh International Airport on the morning of July 10.

The latest batch was purchased from Chinese pharmaceutical firms Sinovac and Sinopharm -- three million from the former and the rest from the latter.

Including this latest shipment, Sambath said Cambodia had acquired a total of 17 million doses to accelerate its nationwide vaccination drive.

By August, Cambodia will have acquired 20 million to vaccinates the targeted 10 million people aged 18 and over. She said the government will continue to procure more vaccines from China and other sources.

"So far, the government has vaccinated nearly 50 per cent of the target. Vaccines prevent patients from developing severe symptoms, but if we fail to take precautions, we can contract the virus easily," she said.

Regarding a possible third dose for vaccinees, she said: "We are studying the effectiveness of the two doses they have received.

Sambath noted that the latest batch of four million doses will be distributed to Covid-19 hotspots including Kandal and other provinces on the Thai and Vietnamese borders.

The Ministry of Health said recently that a total of 33 Delta variant cases had been detected in migrant workers in June.

Prime Minister Hun Sen on July 9 warned that if the Delta variant spread into communities, Cambodia would face “devastation”.

"This time is different from before. In the past, among 1,000 migrant workers who returned from Thailand, only between 20 and 30 tested positive for Covid-19. Now, if 300 migrants come, more than 100 test positive. If it is 500, around 200 are positive,” he said.

He noted that most of them returned through Banteay Meanchey and Oddar Meanchey provinces.