Variants of Covid 19

Variants of Covid 19

Subject: Science and Technology

Context: The continued spread of the SARS-CoV-2 virus has spawned a Greek alphabet of variants – a naming system used by the World Health Organization to track concerning new mutations of the virus that causes COVID-19.

Concept:

DELTA

• The Delta variant first detected in India remains the most worrisome.
• It has proven capable of infecting a higher proportion of vaccinated people than its predecessors.
• The WHO classifies Delta as a variant of concern, meaning it has been shown capable of increasing transmissibility, causing more severe disease or reducing the benefit of vaccines and treatments.
• While the original coronavirus took up to seven days to cause symptoms, Delta can cause symptoms two to three days faster, giving the immune system less time to respond and mount a defense.
• Delta also appears to be mutating further, with reports emerging of a “Delta Plus” variant, a sub-lineage that carries an additional mutation that has been shown to evade immune protection.
• India listed Delta Plus as a variant of concern in June, but neither the U.S. CentersFor Disease Control and Prevention nor the WHO have done so yet. Delta Plus has been detected in at least 32 countries. Experts say it is not yet clear whether it is more dangerous.

LAMBDA – ON THE WANE

The Lambda variant has attracted attention as a potential new threat. But this version of the coronavirus, first identified in Peru in December, may be receding, several infectious disease experts told Reuters.

The WHO classifies Lambda as a variant of interest, meaning it carries mutations suspected of causing a change in transmissibility or causing more severe disease, but it is still under investigation.

 Lab studies show it has mutations that resist vaccine-induced antibodies.

A database that tracks SARS-CoV-2 variants, has been dropping, a sign that the variant is waning.

B.1.621

• The B.1.621 variant, which first arose in Colombia in January, where it caused a major outbreak, has yet to earn a Greek letter name.
• The European Center for Disease Prevention and Control has listed it as a variant of interest, while Public Health England describes B.1.621 as a variant under investigation. It carries several key mutations, including E484K, N501Y and D614G, that have been linked with increased transmissibility and reduced immune protection