Covid-19: Delta Plus Variant

In News

Recently, India has reported nearly 50 cases of Delta plus SARS-CoV-2 variant, with Maharashtra and Tamil Nadu leading with the maximum number of cases.

• The Health Ministry has categorised Delta Plus variant of coronavirus as a ‘variant of concern’. 

About Delta Plus variant

• Delta Plus (B.1.617.2.1/(AY.1) is a new mutant strain of the Delta variant of SARS-CoV-2 and has emerged as a new threat.
• This strain is characterised by the K417N mutation in the spike protein of the SARS-CoV2 virus that causes the Covid-19 disease.
•  The K417N mutation has been associated with “immune escape”, which means that the virus is less susceptible to — or less responsive to — any drug therapy.

• The K417N mutation is within the receptor-binding domain of the spike protein, and this change is noteworthy because this mutation is also found in the B.1.351 or Beta variant of concern.
• The combination of features from other, earlier variants could make Delta Plus adapt better to pull off an immune escape.

• Transmissibility 
  • Experts believe Delta Plus has increased transmissibility but it is still not very clear as to how virulent this new strain is in comparison to other variants.
    • There is no indication yet of the severity of the disease due to the new variant.
• The World Health Organization (WHO) has not classified it as a “Variant of Concern“(VOC) and scientists believe there is not enough evidence to support the claims of this variant being a ‘concern’.
  • WHO classifies a variant as a VOC when it is associated with an increase in transmissibility or detrimental change in Covid-19 epidemiology; increase in virulence; or decrease in the effectiveness of public health measures or available diagnostics, vaccines, therapeutics.
• In the case of the Delta Plus variant, the Health Ministry identified three characteristics — increased transmissibility; stronger binding in receptors of lung cells; and potential reduction in monoclonal antibody response.

Delta Plus Variant in World and  India

• The Delta plus variant has been identified and isolated in over 10 countries and nearly 50 cases have already been seen in India, especially Maharashtra, which is already bracing for a third wave.
  •  In India, it was first reported in a Public Health England bulletin on June 11.
• India warned that regions where it has been found “may need to enhance their public health response by focusing on surveillance, enhanced testing, quick contact-tracing and priority vaccination.”

Concerns 

• Delta Plus is considered highly infectious.
• There is a rising concern in some quarters following warnings by experts that Delta Plus may show resistance against monoclonal antibodies cocktail treatments such as the Roche and Cipla ones being marketed in India at steep prices (almost Rs 60,000 per dose).

• One potential risk that has sparked unease among the medical community is that the new variant may be able to bypass immunity provided by both vaccine and earlier infection.
• There are worries Delta Plus would inflict another wave of infections on India after it emerged from the world’s worst surge in cases only recently.

 Vaccines Effectiveness  Against the Delta Plus Variant

• Medical experts say it is too early to predict the effectiveness of the existing vaccines on the new variant. 
• A detailed study would be required to establish any effect of the mutant on the immune system. 
  • Studies are ongoing in India and globally to test the effectiveness of vaccines against this mutation.
• However, the Union Health Ministry Secretary says that both Indian vaccines — Covishield and Covaxin are effective against the Delta Variant.

Source: TH