The Union Health Ministry categorized the Delta Plus variant of the novel coronavirus, so far detected in three states in the country, as a ‘variant of concern’ and directed states to take up immediate containment measures in clusters where the variant has been detected.

INSACOG, a consortium of 28 laboratories of the Health Ministry that is involved in genome sequencing, informed the Centre that the Delta Plus variant has three worrying characteristics: increased transmissibility; stronger binding in receptors of lung cells; and potential reduction in monoclonal antibody response.

Delta Plus variant or B.1.617.2.1 is closely related to the Delta variant, a major contributor to the second wave of Covid-19 in India. Like Delta, the Delta Plus variant has mutation in the spike protein region of the RNA virus, which potentially makes it more transmissible.

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Viruses constantly change through mutation. A variant has one or more mutations that differentiate it from other variants in circulation. As expected, multiple variants of SARS-CoV-2 have been documented globally throughout this pandemic.

A variant of interest is one that is “suspected” to either be more contagious than the initial strain, cause more severe disease, or escape the protection offered by vaccines.

Variant of Concern

A variant for which there is evidence of an increase in transmissibility, more severe disease (e.g., increased hospitalizations or deaths), significant reduction in neutralization by antibodies generated during previous infection or vaccination, reduced effectiveness of treatments or vaccines, or diagnostic detection failures.

The immune system is made up of special organs, cells, and chemicals that fight infection (microbes). The main parts of the immune system are white blood cells, antibodies(Immunoglobulins), the complement system, the lymphatic system, the spleen, the thymus, and the bone marrow. These are the parts of your immune system that actively fight infection.

White blood cells

The key players in our immune system; made in your bone marrow and are part of the lymphatic system;move through blood and tissue throughout your body, looking for foreign invaders (microbes) such as bacteria, viruses, parasites and fungi so to launch an immune attack. White blood cells include lymphocytes (such as B-cells, T-cells), and many other types of immune cells. 

Antibodies help the body to fight microbes. They do this by recognizing substances called antigens on the surface of the microbe. The antibodies then mark these antigens for destruction. There are many cells, proteins, and chemicals involved in this attack. 

Lymphatic system

The lymphatic system is made up of:

• lymph nodes (also called lymph glands) — which trap microbes
• lymph vessels — tubes that carry lymph, the colourless fluid that bathes your body’s tissues and contains infection-fighting white blood cells
• white blood cells (lymphocytes).

Spleen

The spleen is a blood-filtering organ that removes microbes and destroys old or damaged red blood cells. It also makes disease-fighting components of the immune system (including antibodies and lymphocytes).

Bone marrow

Bone marrow is the spongy tissue found inside your bones. It produces the red blood cells our bodies need to carry oxygen, the white blood cells we use to fight infection, and the platelets we need to help our blood clot. 

Thymus

The thymus filters and monitors your blood content. It produces the white blood cells called T-lymphocytes.

Complement system

The complement system is made up of proteins whose actions complement the work done by antibodies.

The immune system keeps a record of every microbe it has ever defeated, in types of white blood cells (B- and T-lymphocytes) known as memory cells. This means it can recognize and destroy the microbe quickly if it enters the body again before it can multiply and make you feel sick.

Monoclonal antibodies are laboratory-produced antibodies designed to recognize and bind to specific receptors found on the surface of cells. The term monoclonal antibody means that the man-made antibody is synthesized from cloned immune cells, and the identical monoclonal antibody produced binds to one type of antigen. They are derived from natural antibodies, complex proteins derived from a single B cell made by the body’s immunological defense system to recognise and fight foreign invaders such as bacteria and viruses.