The Health Ministry’s team of top medical advisers have provided detailed insights into the COVID-19 virus and its variants including the dominant Delta strain and the newly emerging Delta Plus variant. They point out that COVID-19 virus will continue to mutate as long as the pandemic remains since a virus by its very nature mutates. This is a part of its evolution. Vaccination and strictly following COVID appropriate behaviour are the only ways to defeat it.
India Narrative brings to its readers these key facts in Q & A form.
Q. What are Delta and Delta Plus variants?
These are the names given to variants of SARS-CoV-2 virus, based on the mutations found in them. WHO has recommended using letters of the Greek Alphabet, i.e., Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), Delta (B.1.617), etc., to denote variants, for easier public understanding.
Delta variant, also known as SARS-CoV-2 B.1.617, has about 15-17 mutations. It was first reported in October 2020. More than 60% of cases in Maharashtra in February 2021 pertained to delta variants.
It is the Indian scientists who identified the Delta Variant and submitted it to the global database. Delta variant is classified as a Variant of Concern and has now spread to 80 countries, as per WHO.
Delta variant (B.1.617) has three subtypes B1.617.1, B.1.617.2 and B.1.617.3, among which B.1.617.1 and B.1.617.3 have been classified as Variant of Interest, while B.1.617.2 (Delta Plus) has been classified as a Variant of Concern.
The Delta Plus variant has an additional mutation in comparison to Delta variant; this mutation has been named as the K417N mutation. ‘Plus’ means an additional mutation has happened to the Delta variant. It does not mean that the Delta Plus variant is more severe or highly transmissible than the Delta variant.
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Q. Why is the Delta Plus strain a Variant of Concern?
The Delta Plus variant has been classified as Variant of Concern because of the following characteristics:
· Increased transmissibility
· Stronger binding to receptors of lung cells
· Potential reduction in monoclonal antibody response
· Potential post vaccination immune escape
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Q. How often are these mutations studied in India?
Indian SARS-CoV-2 Genomics Consortium (INSACOG) coordinated by the Department of Biotechnology (DBT) along with Union Health Ministry, ICMR, and CSIR monitor the genomic variations in the SARS-CoV-2 on a regular basis through a pan India multi-laboratory network. It was set up with 10 National Labs in December 2020 and has been expanded to 28 labs and 300 sentinel sites from where genomic samples are collected. The INSACOG hospital network looks at samples and informs INSACOG about the severity, clinical correlation, breakthrough infections and re-infections.
More than 65,000 samples have been taken from states and processed, while nearly 50,000 samples have been analysed of which 50% have been reported to be Variants of Concern.
Q. What is the trend of Variants of Concern circulating in India?
As per the latest data, 90% of samples tested have been found to have Delta Variants (B.1.617). However, B.1.1.7 strain which was the most prevalent variant in India in the initial days of the pandemic has decreased.
Q. Do COVISHIELD and COVAXIN work against the variants of SARS-CoV-2?
Yes, COVISHIELD and COVAXIN are both effective against the Alpha, Beta, Gamma and Delta variants. Lab tests to check vaccine effectiveness on Delta Plus Variant are ongoing.
Delta Plus Variants: The virus has been isolated and is being cultured now at ICMR’s National Institute of Virology, Pune. Laboratory tests to check vaccine effectiveness are ongoing and the results will be available in 7 to 10 days. This will be the first result in the world.
Q. What are the public health interventions being carried out to tackle these variants?
The public health interventions needed are the same, irrespective of the variants. The following measures are being taken:
· Cluster containment
· Isolation & Treatment of cases
· Quarantining of contacts
· Ramping up vaccination
Q. Do public health strategies change as the virus mutates and more variants arise?
No, public health prevention strategies do not change with variants.
Q. Why is continuous monitoring of mutations important?
Continuous monitoring of mutations is important to track potential vaccine escape, increased transmissibility and disease severity.
Q. What does a person do to stay safe from these Variants of Concern?
One must follow COVID Appropriate Behaviour, which includes wearing a mask properly, washing hands frequently and maintaining social distancing.
The second wave is not over yet. It is possible to prevent a big third wave provided individuals and society practise protective behaviour.
Further, Test Positivity Rate must be closely monitored by each district. If the test positivity goes above 5%, strict restrictions must be imposed.
