MANILA (2nd UPDATE) — The Philippines has confirmed its first case of the omicron subvariant XBB.1.5, which experts said is the most transmissible form of COVID-19, a Department of Health report showed on Tuesday.
Out of 1,078 samples sequenced by health authorities from Jan. 30 to Feb. 3, 196 were classified as XBB, including 1 case of XBB.1.5, the DOH said in its latest biosurveillance report.
The XBB cases were found in all regions except Region 8 and the Bangsamoro, the report showed.
The DOH said the European Centre for Disease Prevention and Control classified XBB.1.5, an offshoot of the XBB subvariant, "as a variant of interest due to its increasing prevalence globally and enhanced immune-evading properties."
The variant has been detected in 59 countries across 6 continents, according to sequence submissions in GISAID, a global platform for COVID-19 data.
Based on estimates from the US Centers for Disease Control and Prevention, the subvariant accounted for 66.4 percent of cases in the US from Jan. 29 to Feb. 4, 2023.
According to the rapid risk assessment conducted by the World Health Organization, there is moderate-strength evidence for increased risk of transmission and immune escape, the DOH report read.
However, currently available evidence for XBB.1.5 does not suggest any differences in disease severity and clinical manifestations compared to the original omicron variant, it added.
"Currently, the subvariant is still reported under XBB by the WHO and will remain classified under omicron until sufficient evidence arises showing that the virus characteristics are significantly different from omicron," the DOH said.
The country has also detected its first cases of the new omicron variant CH.1.1, the same DOH report showed.
Results of the samples processed by the Research Institute for Tropical Medicine and University of the Philippines-Philippine Genome Center revealed that 7 cases were identified as BA.2.75, including 3 cases classified as CH.1.1 and 3 cases classified as BN.1.
The recently detected BA.2.75 cases are all local cases from Regions 2, 4A, 4B, 11, and Metro Manila, the report read.
According to the DOH, the CH.1.1 subvariant, a descendant sublineage of BA.2.75, has been classified by the ECDC as a variant under monitoring "due to its increasing prevalence and potential for immune escape."
To date, the subvariant has already been detected in 71 countries across 6 continents, citing sequence submissions to GISAID.
"The subvariant, along with XBB.1.5, is most likely to predominate in the UK following BQ.1," the DOH said.
Currently available evidence for the subvariant does not suggest any differences in disease severity or clinical manifestations compared to the original omicron variant, it added.
DOH reiterated its reminder for everyone to comply with minimum public health standards, get vaccinated and/or boosted, and to know the individual risk assessment in all activities.
It also clarified that even with the detection of new variants and subvariants, the number of COVID-19 cases in hospitals, as well as severe and critical cases remain manageable.