Current COVID-19 wave may be due to Omicron subvariant BA.5 –Genome Center

The Philippine Genome Center (PGC) on Monday said the increase in COVID-19 cases in the past weeks may be attributed to the Omicron BA.5 subvariant which now comprises about 85% of their sequenced samples.

PGC Executive Director Dr. Cynthia Saloma said that of the 1,100 to 1,200 samples being sequenced in the country per week, BA.5 was the “most predominant variant” detected as compared to the other Omicron sub-variants like BA.4, BA.2.12.1, and BA.2.3.

“If we consolidate the data from Visayas, Mindanao, and Luzon… if we look at this in the past month alone, ang BA.5 talaga is the most predominant sample or variant that we are sequencing in the Philippines. It’s about 85% ng ating sequenced samples,” she said at a Laging Handa briefing.

“All in all, we can probably say that this current wave is really the BA.5 wave dito sa ating bansa [in our country],” she added.

Saloma said that based on the PGC’s sequencing analysis, the majority of the detected BA.5 cases in the country were composed specifically of the BA.5.2.

“Other than that, wala naman tayong binabantayan. Binabantayan lang natin kung itong karamihan ng ating BA.5 ay magkakaron pa ng additional mutations,” she said.

(Other than that, we’re not monitoring anything. We are just checking if this majority of BA.5 cases will have additional mutations.)

The Department of Health on Friday reported an additional 95 BA.5 cases in the Philippines, which brought its total caseload to over 3,100.

‘Prolonged wave’

OCTA Research fellow Dr. Guido David said that the COVID-19 wave in the country was lasting longer than expected and could continue until the "ber" months.

“Initially, we expected a two-month wave due to Omicron BA.4 and BA.5 dahil two months lang tumagal sa South Africa… pero hindi pa tayo nasa peak [it only lasted for two months in South Africa, but it hasn't peaked yet]. It’s taking longer,” he said.

“Right now, it’s looking like it will last up to 4 to 5 months, well into the 'ber' months. Pero ‘yung wave natin, it’s possible na prolonged na siya [our current wave may be prolonged] because of maybe the effects of the BA.2.75 that is causing additional infections,” he added.

Last Tuesday, the Department of Health (DOH) announced that the country detected its first two cases of the Omicron subvariant BA.2.75, dubbed  “Centaurus,” in the Western Visayas.

David also said that another possible reason for the prolonged wave would be the waning immunity of those who had the primary vaccine series last year and have not yet taken their booster shots.

OCTA on Monday said that 15 areas in Luzon and five others in the Visayas and Mindanao registered a “very high” or above 20% COVID-19 positivity rate on August 6.

These high-positivity rate areas were Albay, Benguet, Cagayan, Camarines Sur, Cavite, Isabela, La Union, Laguna, Nueva Ecija, Pampanga, Pangasinan, Quezon, Rizal, Tarlac, Zambales, Aklan, Bohol, Capiz, Negros Oriental, and Palawan.

The positivity rate refers to the percentage of people who were found positive for COVID-19 among the total number of individuals tested.

However, David said the increased positivity rate in several areas had not  translated to hospitals being overwhelmed. — DVM, GMA News