India’s Health Ministry has recently reported a newly identified double mutant variant of the coronavirus, adding to the list of Variants of Concern (VOCs) found in 18 states across the nation.
Virus Variant: Understanding Mutations
A virus variant carries one or more mutations which mark it as distinct from other circulating variants. While most mutations may hinder the virus, there are some that make survival easier for it. The SARS-CoV-2 virus (Corona) is known to evolve rapidly due to its widespread infection at a global level. High levels of circulation allow the virus to mutate more easily and replicate faster. The Wu.Hu.1 (Wuhan virus) was the original pandemic virus or founder variant. Within a few months, a new variant D614G emerged and became globally dominant.
Variants Categorization by US CDC
Variants are categorized into three groups according to the US Centers for Disease Control and Prevention (CDC). The classifications include: Variant of Interest (VOI), Variant of Concern (VOC), and Variant of High Consequence. A VOI such as the B.1.617 variant, contains specific genetic markers linked to changes like reduced efficacy of treatments and potentially increased transmissibility. This variant, possessing two mutations E484Q and L452R, has been acknowledged as a VOI by the World Health Organization (WHO) as well.
Variant of Concern: What Makes It Different?
A VOC is characterized by evidence of increased transmissibility, severe disease implications, significant reduction in neutralization by antibodies, lower effectiveness of treatments or vaccines, and diagnostic detection failures. Variants like B.1.1.7 (UK variant), B.1.351 (South Africa Variant), P.1 (Brazil Variant), etc., are classified as VOCs.
Variants of High Consequence and Variants Under Investigation
A Variant of High Consequence shows clear evidence that prevention measures or medical countermeasures have significantly reduced effectiveness compared to previously circulating variants. As per CDC, no such variants are currently found in circulation in the US. Variants Under Investigation (VUI), as defined by Public Health England (PHE), are variants considered for formal investigation based on their epidemiological, immunological or pathogenic properties.
Nomenclature: PANGOLIN
The Phylogenetic Assignment of Global Outbreak Lineages (PANGOLIN) was developed for SARS-CoV-2 lineage classification, using a hierarchical system based on genetic relatedness. Variant lineages are evolving in different geographical areas with Lineage B being the most prolific.
Concerns Related to Different Variants
Variants with increased transmissibility can trigger new wave(s) of epidemic transmission in various countries including India. Regarding virulence, the UK variant is known to be the most dangerous, while South Africa and Brazil variants do not seem to have higher virulence. Another concern is the lowered immunity offered by vaccination against D614G variant, which has led to lower vaccine efficacy especially with South African and less with Brazil variant.
Possible Solution: Hetero Boosting
Karolinska Institute in Sweden has devised a promising solution called ‘hetero boosting’. A new variant Receptor Binding Domain (RBD) peptide with adjuvant is created and used to inoculate monkeys primed with an older vaccine. The resultant booster response was broad and high, covering new variants.
Way Forward
The ongoing pandemic has emphasized the importance of biomedical research and capacity building in saving lives and boosting economic growth. It necessitates a foundation of extensive research in universities, medical colleges and biotechnology companies, all of which must be adequately funded, encouraged, and talent rewarded. The future lies in investing heavily in biosciences, whose products and profit can make us healthier and wealthier in the long run.
