MANILA (REUTERS) - A delay in Covid-19 vaccine deliveries to the Philippines has forced some cities in the capital region to close vaccination sites, complicating Manila's efforts to ramp up its immunisation drive.

Presidential spokesman Harry Roque on Thursday (June 10) appealed for understanding, while assuring the public that the country "will have more supply in the coming months and everyone will be vaccinated".

Only 4.5 million of the 7 million doses of Covid-19 vaccines that were scheduled to arrive in May were delivered, Mr Carlito Galvez, head of the government's vaccine procurement programme, told DZMM radio on Wednesday.

The delay came just as the government opened up vaccinations to around 35 million people working outside their homes, to curb Covid-19 transmission and open up the economy.

Quezon City Mayor Joy Belmonte said some vaccination sites in her city were being forced to close because of "erratic" supplies.

"If we are on full force, we can activate 15 sites already, but given the supply we are activating only eight vaccine sites," she told CNN Philippines.

Quezon City is the Philippines most populous city, with 2.9 million residents, and accounts for 8 per cent of the country's total 1.28 million Covid-19 infections.

In Marikina City, 18,000 people were awaiting the arrival of more vaccines, Mayor Marcelino Teodoro told CNN Philippines.

"The problem is no longer vaccine hesitancy (but) the steady supply of vaccines," he said.

A shipment of 2.28 million Pfizer-BioNTech vaccines secured via Covax was set to arrive in the country on Thursday, but they will be given to senior citizens, people with existing health conditions and the poor.

Including Thursday's vaccine delivery, the Philippines will have received a total of 12.6 million Covid-19 shots, mostly from China, and through the global vaccine-sharing scheme.

As at Monday, the Philippine authorities had fully vaccinated 2.3 per cent of the 70 million people they aim to inoculate against Covid-19 this year.