1. What is it ?
2. Who is the manufacturer ?
Oxford University, in collaboration with AstraZeneca, developed this vaccine. The codename of this vaccine is AZD1222, and it is sold under the brand names : 
- Covishield ( in India ) and
- Vaxzevria ( in European Union ).
In India, the large–scale manufacturing of this vaccine is undertaken by Pune’s Serum Institute of India. Read more: COVID Vaccination Program in India
3. Current pricing of this product :
- Each dose of the vaccine costs around Rs. 300 ( over $ 4 ) in the state government hospitals. While the cost per dose at private hospitals estimate to around Rs. 600 ( around $ 8 ) in India.
- The European Union is currently paying approximately $ 2.15 to $ 3.50 for a shot. The UK and the US pay around $ 3 and $ 4 for each dose of the vaccine respectively.
Covishield: Mechanism of action
- This is a monovalent vaccine composed of a single recombinant, replication–deficient chimpanzee adenovirus vector. It contains the SARS – CoV – 2 spike ( S ) glycoprotein along with a tissue plasminogen activator.
- The active substance or adenovirus vector of this vaccine is called ChAdOx1 – SARS – CoV – 2.
- Following vaccination, the S glycoprotein of the SARS – CoV – 2 viruses is expressed locally in the cells. It further releases its genes that are transported to the cell’s nucleus. This, in turn, gets transcripted to mRNA and finally into proteins by the cell’s machinery or organelles.
- These changes ultimately lead to the stimulation of the neutralizing antibodies. It generates a cellular immune response, such as T–cell production if the virus later infects the body.
- Read about
5. What is the dosage frequency of Covishield ?
- The medicine is administered by two 0.5 ml doses injected intramuscularly into the deltoid muscle ( upper arm ).
- In India, everyone should take the second dose four to eight weeks after the first shot.
- The WHO has recommended the second dose to be given 8 to 12 weeks after the first for optimum efficacy.
6. Is it effective ?
As per recent data, the vaccine is 76.0 % effective in preventing symptomatic COVID–19. The response begins at 22 days following the first dose. This increases up to 81.3 % when the second dose is given 12 weeks or more after the first dose. , 
- In India, this vaccine was granted permission for emergency or conditional use. The DCGI or Drugs Controller General of India granted the permission on 1 January 2021.
- Covishield comprises over 90 % of the total vaccinated population in India. 12.76 crore VOCID – 19 vaccines are administered across India so far ( as of 21 April 2021 ). , 
- As per the Indian government’s CO – WIN portal, around 11,60,65,107 Covishield jabs have been administered in the country.
- Over 15 states have been administering only Covishield vaccines to their beneficiaries. It includes states and Union territories, like Goa, Chandigarh and Jammu, and Kashmir,
- In India, people below 50 years of age often develop side effects such as fever, pain at the site of injection, and soreness. These side effects resolve within two days or more of vaccination. Those older than 50 years of age experienced less severe reactions.
- Centre for Cellular and Molecular Biology, conducted a preliminary study. The study reveals Covishield also offers protection against the ‘ double mutant ‘ strain or Indian variant of the virus.
Global acceptance scenario :
- Over 112 million doses of this vaccine have been administered globally to date.
- It has been approved for emergency or temporary use in the European Union countries and non – EU countries. It is for use in people aged 18 years and above.
- Certain countries worldwide have recently suspended the use of this vaccine. It is due to the manifestation of a few rare blood clotting events in some individuals post–vaccinations.
- The Philippines has suspended the use of this vaccine for people under 60 years of age. Australia has recommended that people under 50 years get Pfizer’s shot in preference to AstraZeneca’s vaccine. 
- Italy, France, the Netherlands, Germany, and other countries have also recommended a minimum age limit for the recipients of this shot.
- Those aged under 30 years in Britain are being recommended to get an alternative over this shot.
- South Korea has also put forth restrictions as it is now suspended for use in people under 60.
- On the other hand, South Africa has dropped its plans to buy the AstraZeneca shots due to global shortages.