- A virus is bound to evolve and mutate the more it spreads
- A mutation is a change in the genome or genetic sequence of a virus
- Some mutations die out and some end up being more transmissible: Experts
New Delhi: Novel Coronavirus (SARS-CoV-2), the virus that causes COVID-19 disease among humans has evolved and mutated multiple times since it was first reported in China’s Wuhan in December, 2019. A mutation is a change in the genome or genetic sequence of a virus which results in a new strain of the virus. “This is a natural evolution and the virus is expected to change the more the virus circulates around”, said Dr Maria Van Kerkhove, WHO COVID-19 Technical Lead. But why DO some variants end up becoming ‘variants of concern’? How are ‘variants of concern’ different from ‘variants of interest’? How does WHO classify a variant as a variant of concern?
Experts answer all the questions on coronavirus and its variants.
What Is A Mutation?
SARS-CoV-2 coronaviruses share a genome that looks a little different from specimen to specimen. Each time a virus makes copies of itself, one or more of the letters in the genome can be written incorrectly. Coronaviruses are pretty good at proofreading, but mistakes still get through. This is how genetic mutations arise, and it’s all perfectly normal, explained Dr Sunil Jain, Head of emergency medicine at Jaslok Hospital and Research Centre.
Dr Jain further said that if a mutation makes it more difficult for the virus to replicate — for instance, if it results in a physical change that hampers its ability to get inside a host cell — that virus will die out and take the mutation along with it. But, if a mutation gives the virus a competitive advantage, it will spread more quickly than its rivals. That’s how some variants die out and some become ‘variants of concern.’
Variants Of Interest
Variants of interest (VOI) have properties, have mutations that have been identified that need further study, said Dr Kerkhove. As per WHO, variant becomes a ‘variant of interest’ when it has been identified to cause community transmission or multiple COVID-19 cases or clusters, or has been detected in multiple countries. Apart from this, a variant is assessed to be a VOI by WHO in consultation with the WHO SARS-CoV-2 Virus Evolution Working Group.
As per WHO’s latest update on May 31, there are six variants of interest –
– Epsilon and Iota both first found in the USA;
– Zeta, first reported in Brazil;
– Eta which has been found in multiple countries;
– Theta, first documented in samples from the Philippines;
– Kappa, a variant found in India.
Variants Of Concern
Variants of concern have demonstrated changes. For example, you may have increased transmissibility, there may be a change in disease presentation or severity, or there may be a change in our ability to control the virus with public health and social measures, or the use of diagnostics, therapeutics and vaccines. So the recent variant of concern, the B.1.617, for example, has demonstrated increased transmissibility and this is why this has been classified as a variant of concern, explains Dr Kerkhove.
Alpha, Beta, Gamma, and Delta are the current four variants of concern. As per WHO, the Delta variant was first reported in India in October, 2020. As per the latest update from WHO, the Delta variant’s lineage B.1.617.2 is the only strain of concern at the moment. The UN health agency last month declared the entire strain a variant of concern but on June 1, it said only one of the sub-lineages deserved that label.
Variants of High Consequence
A variant of high consequence has clear evidence that prevention measures or medical countermeasures (MCMs) have significantly reduced effectiveness relative to previously circulating variants, states the United States’ Centers for Disease Control and Prevention (CDC).
Possible attributes of a variant of high consequence include:
– demonstrated failure of diagnostics;
– evidence to suggest a significant reduction in vaccine effectiveness;
– a disproportionately high number of vaccine breakthrough cases;
– more severe clinical disease and increased hospitalisations.
As per CDC, currently, there are no SARS-CoV-2 variants that have risen to the level of high consequence.
What Can One Do For Protection Against Coronavirus Variants?
Dr Kerkhove says that we need to do everything that we can to prevent infections and reduce the spread of the SARS-CoV-2 virus, whether it’s a virus variant, a variant of interest or a variant of concern or not, the SARS-CoV-2 virus can infect us and it can spread between people.
It means take all of the measures that you can to reduce your exposure in the possibility of you getting infected. It means physical distancing, avoiding crowded spaces, spending more time outdoors than indoors. If you are indoors, make sure that there’s good ventilation. It’s about having clean hands and wearing a mask properly over your nose and your mouth, practising respiratory etiquette, being well informed. And no matter what you do know what your risk is and take steps to lower your risk. And lastly, when it’s your turn, get vaccinated, said Dr Kerkhove.
WHO COVID-19 Technical Lead also informed that multiple studies are underway to study the nature of multiple variants in terms of transmissibility, severity and impact on diagnostics, therapeutics and vaccines. The current evidence suggests that vaccines and other control and diagnostics measures do work against the variants.
NDTV – Dettol Banega Swasth India campaign is an extension of the five-year-old Banega Swachh India initiative helmed by Campaign Ambassador Amitabh Bachchan. It aims to spread awareness about critical health issues facing the country. In wake of the current COVID-19 pandemic, the need for WASH (Water, Sanitation and Hygiene) is reaffirmed as handwashing is one of the ways to prevent Coronavirus infection and other diseases. The campaign highlights the importance of nutrition and healthcare for women and children to prevent maternal and child mortality, fight malnutrition, stunting, wasting, anaemia and disease prevention through vaccines. Importance of programmes like Public Distribution System (PDS), Mid-day Meal Scheme, POSHAN Abhiyan and the role of Aganwadis and ASHA workers are also covered. Only a Swachh or clean India where toilets are used and open defecation free (ODF) status achieved as part of the Swachh Bharat Abhiyan launched by Prime Minister Narendra Modi in 2014, can eradicate diseases like diahorrea and become a Swasth or healthy India. The campaign will continue to cover issues like air pollution, waste management, plastic ban, manual scavenging and sanitation workers and menstrual hygiene.