Here's what we know so far about Omicron BA.5 subvariant
After months of recording low infections, the Philippines is seeing a rise in COVID-19 cases, with the Department of Health (DOH) noting that detected infections rose by 82% in one week. Cases of the Omicron subvariant BA.5 have also been increasing since the health agency confirmed its detection earlier in June.
The original Omicron strain caused a rise in cases in January 2022 and is said to be more transmissible than the Delta, Alpha, and Beta variants. A sublineage of Omicron, the BA.5 strain, started raising concerns in May, driving surges in different countries, including the United States, England, Portugal, France, and Germany. In Portugal, 80% of all their new infections are of this variant.
BA.5 carries the same mutations as the original Omicron variant but also carries the L452 mutation previously found in the Delta variant. This makes the virus more contagious as it has an enhanced ability to attach to human cells and provides it with the ability to escape immunity granted by previous infections.
Symptoms and spread
Those infected with the subvariant experience similar symptoms from the Omicron strain. Symptoms that a BA.5-infected individual may experience include runny nose, cough, sore throat, fever, headaches, muscle pain, and fatigue.
Individuals who were previously infected with other strains of COVID and Omicron may still get BA.5. The newer subvariants have additional mutations in the spike protein enabling them to evade immunity.
Professor David Montefiori of the Human Vaccine Institute at Duke University Medical Center told NBC News that BA.5 and BA.4 are more contagious than earlier Omicron variants. A pre-print publication in South Africa also shows that the latest subvariants have a reproductive rate of around 18.6—almost as contagious as measles.
Harvard-trained physician Dr. Mallika Marshall told CBS News that being at an outdoor event could put you at risk for new Omicron subvariants. "You could even get Covid even if you have a brief encounter with someone who is infected."
Will Omicron BA.5 cause a surge in the Philippines?
However, infectious disease expert Dr. Edsel Salvaña said that BA.5 is "not the worst COVID-19 variant" in the Philippines.
"That distinction currently belongs to Delta which killed more people than any other variant locally and almost caused our healthcare system to collapse. The deadliness of Delta was a combination of the virulence of the variant and a lack of widespread vaccination," he wrote on July 13.
Salvaña added that BA.5 is likely less virulent than the Delta strain, and because of widespread vaccination, he does not expect the subvariant to overwhelm healthcare systems like Delta.
"It does seem to be more immune evasive than other variants so we expect a lot of cases but only a few of these will be severe or critical. Masks and antivirals still work. Vaccines continue to protect against severe disease and work better with a booster."
So far, data from South Africa and the United Kingdom found that the BA.5 and BA.4 surges did not bring severe disease and death.
Brief trip back into Covid data today:
— John Burn-Murdoch (@jburnmurdoch) May 30, 2022
Promising news from South Africa, where the BA.4 / BA.5 variant wave has passed quietly, with high levels of immunity meaning this wave has had little impact on rates of severe illness or death pic.twitter.com/C5W6iZzDLK
The DOH also said the subvariant does not cause severe and critical disease and that the country's existing protocols to curb the transmission still work.
