MANILA - A public health expert on Monday sounded alarm on the presence of the coronavirus Delta and Lambda variants in the country, saying it could further drive COVID-19 infections as millions remain unvaccinated.

The Delta variant is highly transmissible while the Lambda variant is reportedly more infectious, said Dr. Tony Leachon, a former adviser to the government's coronavirus task force.

"Kung magka-surge, hindi natin mauugnay kung 'yan ba ay Delta o Lambda kasi magkakasama sila," he told ABS-CBN's TeleRadyo, citing the country's limited genomic sequencing capacity.

(If there will be a surge, we can't tell if it's due to Delta o Lambda variants because both are already present.)

• PH confirms first case of COVID-19 Lambda variant

The Philippines on Sunday reported its first case of the Lambda variant, which was first identified in Peru.

The patient is a 35-year-old pregnant woman, who tested positive in July and has since recovered, according to the Department of Health.

• Philippines' first Lambda variant patient, not an OFW: DOH

While the Lambda variant is still considered "variant of interest" by the World Health Organization, Leachon said he couldn't help but worry.

Variant of interest means it carries mutations suspected of causing a change in transmissibility or causing more severe disease but it is still under investigation.

"According to the CDC (Centers for Disease Control and Prevention) at kay Dr. Anthony Fauci, 'pag mababa 'yung vaccination rate ng isang bansa, puwedeng maglamyerda o ibig sabihin puwedeng kumalat at maging mabagsik ang variant," Leachon said.

(According to the CDC and Dr. Anthony Fauci, if a country has low vaccination rate, the variant may spread and get stronger.)

Fauci is America's top infectious disease expert.

More than 12 million people are fully vaccinated in the Philippines or 16.98 percent of its target 70 million adult Filipinos.

'MORE RESISTANT'

Japanese researchers have found that the Lambda variant is more resistant to vaccines than the original version of the virus that emerged from Wuhan, China.

In laboratory experiments, they found that 3 mutations in Lambda's spike protein, known as RSYLTPGD246-253N, 260 L452Q and F490S, help it resist neutralization by vaccine-induced antibodies. Two additional mutations, T76I and L452Q, help make Lambda highly infectious, they found.

Although it is not clear yet whether this variant is more dangerous than the Delta now threatening populations in many countries, senior researcher Kei Sato of the University of Tokyo believes "Lambda can be a potential threat to the human society."

But Dr. Eric Topol, a professor of molecular medicine and director of the Scripps Research Translational Institute in La Jolla, California, said the percentage of new Lambda cases reported to GISAID, a database that tracks SARS-CoV-2 variants, has been dropping, a sign that the variant is waning.

In a recent call with the CDC, disease experts had said Lambda did not appear to be causing increased transmissibility, and vaccines appear to be holding up well against it, said Dr. William Schaffner, an infectious diseases expert at Vanderbilt University Medical Center who attended the discussion.

As of Aug. 12, the Philippines has also recorded 807 cases of the Delta variant, of which 17 have died. The tally includes 771 recoveries and 14 active cases, the DOH said.

- With a report from Reuters