The coronavirus pandemic has been a major health problem worldwide. More than 190 million people have been infected globally. Moreover, the recent emergence of newer variants and their spread has been a challenging and perplexing concern to health care systems throughout the world. So, what actually are the variants?
Understanding the variants
As viruses continue to spread, they acquire mutations and become more diverse. Most mutations have little or no consequences, but some affect the spread, severity of illness, diagnostic tools and response of the virus to existing forms of treatment and vaccines.
The World Health Organization, in collaboration with its team of experts, national authorities, and researchers, has been continually monitoring and assessing the newer variants, and for the ease of public discussion names have been assigned for them according to Greek letters, although the scientists use different naming systems.
The continued assessment of circulating forms of variant has led to characterization of “variant of concern”, and “variant of interest” by WHO, and additional “variant of high consequence” by the Centre for Disease Control and Prevention (CDC) of the United States.
Variants of concern (VOC) and variants of interest (VOI) are different things. Variants of interest (VOI) are the viruses with genetic changes that affect the disease transmissibility and severity causing immune escape, diagnostic and therapeutic escape, with a significantly increased community transmission and number of cases worldwide. The currently designated variants of interest are Eta, Iota, Kappa and Lambda.
Although the new mutations alter the virus responsiveness to post-vaccinated sera, promising results from multiple studies have shown reduction in hospitalization and case fatality in vaccinated individuals.
Variants of concern (V0C) are the VOI with one or more of the following characteristics: It increases transmission or causes detrimental changes in Covid-19 epidemiology, it has an increased virulence or pattern of clinical presentation and it may be immune to established form of treatments, vaccines or diagnostic detection. Alpha, Beta, Gamma and Delta are the variants of concern. Alpha variant was first identified in the UK, Beta in South Africa, Gamma in Brazil, and Delta in India. All of them have been demonstrated to be associated with increase in transmissibility, severity, case fatality, reduced responsiveness to treatment and post-vaccinated sera. Delta plus, a sub lineage of Delta variant with an additional mutation, K147N, has been recently seen in Nepal and India. This could prove to be an alarming threat for the third wave in our country.
Do vaccines help?
Although the new mutations, or variants, also alter the virus responsiveness to post-vaccinated sera, promising results from multiple studies have shown reduction in hospitalization and case fatality in vaccinated individuals. However, a complete dose of vaccination (for vaccines requiring double shots) is a must.
There still lies the possibility of emergence of newer variants. As long as the virus spreads through the population, it continues to mutate. In this situation, proven methods of disease control, complete vaccination and compliance with protective measures and safety protocols are crucial for containing the virus and preventing the development of newer strains and variants. While health facilities have to be equipped with resources to tackle the possible third wave, people, on their part, need to follow the safety protocols to keep themselves safe.
Dr Kusum Paudel is a medical doctor.