AstraZeneca COVID-19 vaccine may be ‘ineffective’ if PH fails to contain South African variant: expert

Davinci Maru, ABS-CBN News

Posted at Mar 03 2021 05:24 PM | Updated as of Mar 03 2021 08:06 PM

AstraZeneca COVID-19 vaccine may be ‘ineffective’ if PH fails to contain South African variant: expert 1
A health-care worker prepares to administer a dose of the Oxford University-AstraZeneca vaccine, marketed by the Serum Institute of India (SII) as COVISHIELD, against COVID-19, in Santiago, Dominican Republic, Feb. 17, 2021. Ricardo Rojas, Reuters/File

MANILA - Some 17 million doses of AstraZeneca COVID-19 vaccine that the Philippines have procured may become ineffective if the Philippines fail to contain the more contagious coronavirus variant that was first detected in South Africa, a group of experts warned Wednesday.

"If we don't eliminate the B.1.351 variant in the Philippines, which was first identified yesterday in Pasay, the 17 million doses of AstraZeneca that we have already bought and have not yet arrived will be ineffective against fighting this particular variant from South Africa," biology professor Nicanor Austriaco of OCTA Research Team said in a press briefing.

The Philippines has purchased 17 million doses of anti-coronavirus shots from the British pharmaceutical firm, with the help of private firms and local government units. The vaccines are expected to be delivered in mid-2021.

Under the Vaccine-sharing COVAX facility, the country can also receive up to 9.2 million doses of AstraZeneca vaccine in March at the earliest, the World Health Organization had said.

According to Austriaco, the efficacy of the AstraZeneca vaccine against the South Africa coronavirus variant decreased from 70 percent to 10 percent. The vaccine was developed together with Oxford University.

He cited a paper published in February from a laboratory in South Africa that tested the jab.

"It was no different than injecting water into patients. With 10 percent protection, basically, most people will still get mild or moderate COVID-19," added Austriaco, who teaches at the Providence College in the US.

South Africa has paused its use of AstraZeneca COVID-19 vaccine after a small clinical trial showed the jab offered minimal protection from the variant. It shifted to using the vaccine developed by Johnson & Johnson.


Austriaco raised concern after health authorities on Monday reported the detection of the South Africa coronavirus variant in the Philippines.

Three of them were found in Pasay City and 2 others from returning Filipino migrant workers from Qatar and United Arab Emirates. The health ministry is still verifying the location of the other case.

Austriaco said the recent spike of COVID-19 cases in Pasay City, where dozens of villages were placed on lockdown, "has the hallmarks of a variant-driven surge."

As of March 1, the South Africa coronavirus variant, called in the US as a "Super-COVID" variant, has been found in 48 countries, he said. 

"We still have a window to eliminate the B.1.351 from circulation. I am hoping that Pasay can contain the spread," Austriaco said. "If the LGU can eliminate the B.1.351, then we are safe. Otherwise, we will have to talk about other options."


The Philippines on Monday begun its COVID-19 vaccination drive, with mostly health workers the first in line to get the shots. It used jabs donated by China's Sinovac Biotech.

While there is no vaccine that currently addresses the South Africa COVID-19 variant, several studies show that inactivate vaccine or using a dead version of a coronavirus strain to trigger an immune response works against prevailing variants, a pediatric infectious diseases specialist said.

"Theoretically, inactivated vaccine should work better than the viral vector vaccine and the MRNA vaccines," Dr. Benjamin Co, who heads the UST Hospital’s pediatric infectious diseases section, told reporters.

Sinovac uses an inactivated vaccine while AstraZeneca shot is a viral vector vaccine. The viral vector vaccine uses a weakened version of a chimpanzee common cold virus that encodes instructions for making proteins from the novel coronavirus to generate an immune response and prevent infection.

Austriaco also said the inactivated vaccine gives broader protection than viral vector vaccine.

"Inactivated vaccine historically have lower efficacy rate but their protection is broader because you are injecting the entire virus to the patient," he said.

"The other vaccine is you are injecting the spike protein or little part of spike protein. So, what happens is [when there's] a slight change and your vaccine is now very poor." 

For him, with the presence of the South Africa coronavirus variant, an inactivated vaccine like Sinovac is the better option.

"When people ask me at this time, which is better between Sinovac and AstraZeneca, I'd say given the identification of the B.1.351 variant in Pasay, in terms of the longer goal, you might want to pick Sinovac over AstraZeneca because even though the efficacy for Sinovac is a little bit lower than AstraZeneca, it will protect you against the B.1.351 while AstraZeneca will not," Austriaco said.