By Christine Fabro and Pearl Gumapos
The World Health Organization (WHO) has classified COVID-19 variants into three types: variants of concern (VOC), variants of interest (VOI), and variants of high consequence.
These variants were recently labeled with new naming conventions using the Greek alphabet to avoid stigmatizing the countries where they were first detected.
Read more: COVID-19 variants get new naming system using the Greek alphabet
VOC is a variant for which there is evidence of an increase in transmissibility, more severe disease, significant reduction in neutralization by antibodies generated during previous infection or vaccination, reduced effectiveness of treatments or vaccines, or diagnostic detection failures.
Meanwhile, VOI has specific genetic markers that have been associated with changes to receptor binding, reduced neutralization by antibodies generated against previous infection or vaccination, reduced efficacy of treatments, potential diagnostic impact, or predicted increase in transmissibility or disease severity.
Under VOC are the following variants:
Alpha (B.1.1.7, UK)
The Alpha variant was first detected in September 2020 and was designated a strain of particular concern in December. It is estimated to be at least 50% more transmissible than the first detected strains of COVID-19.
Beta (B.1.351, South Africa)
This is the oldest of the COVID-19 variants of concern, having been first detected in May 2020.
Delta (B.1.617.2, India)
Experts claim this variant has increased transmissibility or detrimental change in epidemiology, increased virulence or change in disease presentation, and decreased effectiveness of prevention and control measures.
It was first detected in October last year in India, and is considered highly contagious.
Delta Plus (AY.1, India)
This particular variant spreads more easily, binds more easily to lung cells, and is potentially resistant to monoclonal antibody therapy.
Experts say this variant is more infectious than the initial Delta variant.
Gamma (P.1, Brazil)
This variant was first detected in Japan in travellers from Brazil. The strain raised concerns because it may have been the variant responsible for a surge in cases in Manaus, Brazil, where the population was thought to have reached herd immunity. It was first discovered in November 2020.
The following are included among the VOI:
Eta (B.1.525, Nigeria)
Its attributes are the potential reduction in neutralization by some EUA monoclonal antibody treatments, and potential reduction in neutralization by convalescent and post-vaccination sera.
Epsilon (B.1.427/B.1.429, USA)
Its attributes are 20% increased transmission and modest decrease in susceptibility to the combination of bamlanivimab and etesevimab; however, the clinical implications of this decrease are not known.
Theta (P.3, Philippines)
The variant was first identified in the Philippines on February 18, 2021, when two mutations of concern were detected in Central Visayas. It is said that the variant may be more resistant to neutralizing antibodies, including those gained through vaccination.
Kappa (B.1.617.1, India)
It was first detected in India and is treated by the WHO as a variant of interest. Despite this, it is still highly contagious and potentially deadly.
There are currently no variants of high consequence.
Rapid spread of Delta variant, vaccine efficacy against VOCs
Health experts warn the public about the rapid spread of the Delta variant across 80 countries, including the Philippines.
In a Malacañang public briefing on June 21, Dr. Cynthia Saloma from the Philippine Genome Center said the Delta variant is 60% more transmissible than the Alpha variant, which is already about 60% more transmissible than other variants.
According to studies, the Delta variant can infect up to eight persons, compared to the Alpha variant that can infect four to five individuals.
The Food and Drug Administration (FDA) assured the public that COVID-19 vaccines are still effective despite reports of low efficacy rates against COVID-19 variants.
FDA Director-General Eric Domingo cited on June 21 some studies that show the decrease in the efficacy rate of the Pfizer and AstraZeneca vaccines when used on the Delta variant that was first detected in India.
Compared to the Alpha variant, the Pfizer vaccine’s efficacy has decreased from 93% to 88%, while the AstraZeneca vaccine decreased from 66% to 60%.
Read more: FDA: Vaccines are still effective vs. COVID-19 Delta variant
Delta vs. Delta Plus
Medical expert Dr. Eva Maria Cutiongco-dela Paz from the University of the Philippines Manila – National Institutes of Health said in a Laging Handa public briefing on June 26 that the Delta Plus variant has not been identified as a VOC.
The Delta Plus variant has an additional mutation that could “contribute to the immune response escape of the variant.”
While the Delta variant has L452R, P681R, and T478K mutations, the Delta Plus variant has an additional mutation in the spike region – K417N.
Citing the result of the latest genome sequencing, she said there are only 17 Delta variant cases in the country – all from returning international travelers, with no local case recorded yet.
Read more: Delta Plus not yet a variant of concern: expert
To contain the spread and entry of such variants, experts urge the public to not be complacent and to strictly observe the health and safety protocols.
Saloma said there is a unique opportunity to prevent the entry of such a variant and the spread in the communities through strong border control, as the detected cases were all international travelers and were immediately contained.
Agreeing, National Task Force (NTF) Against COVID-19 Deputy Chief Implementer Sec. Vince Dizon said in a Laging Handa public briefing on June 25 that the PDITR (prevention, detection, isolation, treatment, and reintegration) strategy must always be observed to prevent the spread and potential mitigation of VOCs, especially the Delta variant. – jlo
Read more: Tighter border control may prevent community spread of Delta variant, says health expert
