With the approval of the Johnson and Johnson vaccine, India now has four vaccines for emergency use. The other four are AstraZeneca's Covishield, Bharat Biotech's Covaxin, Russia's Sputnik V and Moderna .
Here's a lowdown on the approved vaccines:
COVISHIELD
Vial of Covishield vaccine. Photo: Getty Images
CREATORS: Covishield is developed by Oxford University and is currently being produced by the Serum Institute of India.
COURSE: The vaccine course consists of two doses, 0.5 ml each, and is being actively administered in the country. The Indian government recommends a 12-16 week gap between both doses. So far, around 73 crore doses have been administered in India.
ADMINISTRATION: The vaccine is administered as an intramuscular (IM) injection only in the deltoid muscle.
HOW IT WORKS: Covishield uses a viral vector made of a weakened strain of the common cold virus (adenovector) found in chimpanzees. The common cold virus contains genetic material that is similar to the Covid-causing novel coronavirus. When administered, the immune system recognises the spike protein and begins creating antibodies. (Read more here.)
COVAXIN
Vial of Covaxin vaccine. Photo: Getty Images
CREATORS: Covaxin was developed by Bharat Biotech in collaboration with the Indian Council of Medical Research, and is exclusively produced by Bharat Biotech.
COURSE: Covaxin is also a two-dose vaccine. The Indian government recommends a 4-week gap between doses, and 9 crore doses have been administered in the country so far.
ADMINISTRATION: Covaxin is administered as an injection into the deltoid muscle of the upper arm.
HOW IT WORKS: The vaccine is developed using “Whole-Virion Inactivated Vero Cell” derived platform technology. Inactivated vaccines do not replicate, and are therefore unlikely to revert and cause pathological effects. They contain dead virus; incapable of infecting people but still able to instruct the immune system to mount a defensive reaction against an infection.
SPUTNIK V
Vial of Sputnik V vaccine. Photo: Getty Images
CREATORS: The Sputnik V vaccine has been developed by Moscow's Gamaleya Institute. In India, Dr Reddy Labs is manufacturing Sputnik V in association with Russian Direct Investment Fund and Panacea Biotech. The Serum Institute of India has also received the DCGI nod to produce Sputnik V.
COURSE: The vaccine is an adenoviral-based, two-part vaccine. As per the CoWIN website, 9 lakh doses have been administrated in the country.
ADMINISTRATION: Sputnik V is injected into the upper arm.
HOW IT WORKS: Sputnik V uses a weakened virus to deliver small parts of a pathogen and stimulate an immune response. The first vaccination leads to humoral cellular immunity, and once a second vaccination is administered, memory cells are formed. (Read more here.)
JOHNSON AND JOHNSON
Vials of Johnson and Johnson vaccine. Photo: Getty Images
CREATORS: The Johnson and Johnson vaccine was developed by the Janssen Pharmaceutical Companies of Johnson & Johnson. India is expected to receive as many as 43.5 million doses starting October 2021.
COURSE: The Johnson and Johnson vaccine is a single dose vaccine.
ADMINISTRATION: The vaccine is an intramuscular injection in the deltoid muscle (the upper arm).
HOW IT WORKS: "The J&J vaccine teaches the immune system to attack the protein that causes the coronavirus to infect other cells," explains Healthline.
MODERNA
Vials of Moderna vaccine. Photo: Getty Images
CREATORS: The Moderna vaccine was developed by its namesake, Moderna Inc . India has approved of Moderna yet is still to begin administration.
COURSE: Moderna is a two dose vaccine.
ADMINISTRATION: The vaccine is injected in the deltoid muscle (the upper arm).HOW IT WORKS: Moderna uses mRna to teach the immune system to prevent infection from the coronavirus The mRna gives the body's muscles to create a harmless piece of the virus known as "spike protein". The immune system then creates antibodies in respose to this piece.