By Vann Marlo M. Villegas and Kyle Aristophere T. Atienza, Reporters

ABOUT 250,000 coronavirus vaccines should be given to residents of Metro Manila and eight priority areas daily to achieve herd immunity by November, according to a research group from the country’s premier university.

At least 51.8 million vaccine doses are needed to vaccinate 70% of the population in these areas, or about 25.9 million adults, the OCTA Research Group said on Wednesday.

It would take 17 months to achieve herd immunity if 100,000 doses were given daily, eight months for 200,000 doses daily, and almost six months for 300,000 doses daily, OCTA research fellow Nicanor Pier Giorgio Austriaco told an online news briefing.

The government seeks to achieve herd immunity — when a majority of the population becomes immune from an infectious disease, either through vaccination or a previous infection, indirectly protecting those without immunization — by Nov. 27.

“If we are going to be doing this in the six-month period, we need to have 250,000 to 275,000 doses administered per day on the average of this six month period,” Mr. Austriaco said.

“The risk for a surge is substantially diminished as we approach containment,” he added.

Also part of the priority areas aside from the capital region are Metro Cebu, Metro Davao and the provinces of Bulacan, Batangas, Cavite, Laguna, Pampanga and Rizal.

OCTA said prioritizing these areas for vaccination would “optimize the scarce vaccines to give the maximum impact.”

Mr. Austriaco said this would build “an immunity wall” around international entry ports in Manila and Cebu. This will also revitalize the economy and restart domestic tourism.

The Health department on Tuesday said it supports President Rodrigo R. Duterte’s order to prioritize Metro Manila and the eight other areas. It said 67% of the vaccine supply is given out in Metro Manila, the Calabarzon region, Central Luzon Central Visayas and the Davao region.

Meanwhile, OCTA research fellow Fredegusto Guido P. David said coronavirus infections in Metro Manila had fallen by 80% since a surge that started in March.

He said the daily infection average in Metro Manila in the past seven days stood at 1,099, lower than 5,550 during the peak in late March to April.

“This is a significant improvement and obviously we want to sustain this,” he told the same briefing. “We should remind everyone that even though we have made significant improvements, the National Capital Region will always be at risk of another surge.”

Mr. David said the capital region had a virus reproduction rate of 0.53, lower than more than two at the peak in July and August last year. A reproduction rate of 1 means an infected person can infect one more. 

He also recommended that the general lockdown be retained in June. “We should try to retain the general community quarantine at this time because the cases are still significant.”

He said Metro Manila had about 400 cases daily in February, when it  was still under a general lockdown.

“It also gives us the wrong messaging to the people,” he said about relaxing the quarantine. “We want to avoid situations where people become very complacent because they feel that the situation has improved significantly.”

Mr. David said the heightened restrictions could be relaxed by increasing the capacity in businesses that have been following protocols, while making sure that transmissions do not occur. Social gatherings should also be avoided.

Meanwhile, at least a million Filipinos have been fully vaccinated against the coronavirus since the government’s vaccination drive started on March 1, Health Undersecretary Myrna C. Cabotaje told a separate online news briefing.

Of the total, 581, 797 were health workers, while 195,952 were seniors. More than 250,000 seriously ill people and 535 essential workers had also been fully vaccinated, she added.

Ms. Cabotaje said about 3.4 million people have not completed their vaccination, having received only their first dose.

About 22.4 million people were essential workers whose vaccination would start next month, she said, citing data from the National Economic and Development Authority.

About 8.5 million people were considered poor, she added.

The government earlier said essential workers and indigents would be vaccinated once the country’s supply of vaccines stablizes.  

Rabindra Abeyasinghe, the World Health Organization’s representative in the Philippines, earlier said the country would take delivery next month of as many as two million doses of the vaccine made by Pfizer, Inc. under a global initiative for equal access.

About two million doses of the vaccine made by AstraZeneca Plc would also arrive in June, he said.

The Philippines may receive next month about 4.5 million more doses of the vaccine made by Sinovac Biotech, Ltd., vaccine czar Carlito G. Galvez, Jr. earlier said.

Meanwhile, Ms. Cabotaje said more than a million doses of the two million AstraZeneca vials that the Philippines received earlier this month under the global initiative had been given out.

About 500,000 doses that will expire on July 30 would be given as second doses. The vials reserved as first doses will expire on June 30.