Defense vs Delta, other variants

Alexey Solodovnikov, Valeria Arkhipova/CC BY-SA 4.0/Wikimedia Commons

The Department of Health on Monday reported that five Delta cases were detected in the Bangsamoro Autonomous Region in Muslim Mindanao (BARMM) — meaning that the Delta variant is now all over the Philippines.

On Aug. 31, a day before the Philippines’ coronavirus disease 2019 (COVID-19) cases total topped two million, the World Health Organization (WHO) confirmed that the highly transmissible Delta variant was the dominant SARS-CoV-2 variant in the country. SARS-CoV-2 is the virus that causes COVID-19.

“The Delta variant is rapidly overtaking the Alpha variant as the dominant variant of concern globally,” said Dr. Cynthia P. Saloma, executive director of the Philippine Genome Center and professor at the National Institute of Molecular Biology and Biotechnology of the University of the Philippines-Diliman, in a health forum on Sept. 2.

The earliest Delta variant sample was reported on Sept. 22, 2020, in India. As of this August, 146 countries have reported Delta variant cases, according to Dr. Saloma.

Aside from Alpha (first reported in the UK) and Delta, the other variants of concern are Beta (first reported in South Africa) and Gamma (first reported in Japan and Brazil).

She noted that since this April, there has been a rapid increase in the number of sequenced Delta variant cases worldwide. In all regions of the world except South America, the level of spread of the Delta variant is well over 90% — 98% in Africa, 92% in Asia and Europe, 99.9% in Oceania, and 98% in North America.

The first Delta variant sample in the country was reported on April 24, with the first local Delta variant case reported the next month in Antique province.

According to the US Centers for Disease Control and Prevention (CDC), the Delta variant causes more infections and spreads faster than earlier forms of SARS-CoV-2, and might cause more severe illness than previous strains in unvaccinated people. Experts believe that the Delta variant’s numerous spike protein mutations are responsible for its increased transmissibility and tendency to cause severe disease.

“The Alpha variant is more transmissible than the original reference strain from Wuhan, China, but the Delta variant is 60% more transmissible than the Alpha variant. The Delta variant is associated with a different set of symptoms, and people infected with it are more likely to be hospitalized. Data from different countries, particularly the UK and Israel, indicate that one vaccine dose is less effective but two doses still provide strong protection,” Dr. Saloma said.

She added that the proportion of variants of concern in the set of samples sequenced by the Philippine Genome Center since April has reached over 90%.

June to July saw a steep 42% increase in the proportion of sequenced Delta variant cases in the country. The increase is even more pronounced in the National Capital Region: In June, sequenced Delta variants represented 10% of cases in NCR. By July, this had increased to 78% — a seven-fold increase.

“We saw a much higher number of cases in August,” said Dr. Saloma, who also briefly discussed the Lambda variant, a variant of interest first detected in Peru in Dec. 2020.

As of August, 33 countries reported Lambda variant cases, with the number of cases worldwide progressively declining. “Vaccines prevent severe disease and hospitalization among those infected with the Lambda variant,” said Dr. Saloma.

She added that only one Lambda variant case has been detected in the country in July involving a 35-year-old female with no travel history. “Local transmission of the Lambda variant is not likely; this variant is not a concern at the moment.”

Dr. Saloma warned that viral mutations and the emergence of new variants will likely continue. “Vaccination and the practice of minimum public health standards are our best defense against SARS-CoV-2 variants,” she said.

Teodoro B. Padilla is the executive director of Pharmaceutical and Healthcare Association of the Philippines (PHAP), which represents the biopharmaceutical medicines and vaccines industry in the country. Its members are at the forefront of research and development efforts for COVID-19 and other diseases that affect Filipinos.