Written By Mahi Parui (Grade 8)
What is a vaccine?
A vaccine is a substance used to increase the production of antibodies to fight diseases and provide immunity against one or more disease. It typically contains an agent that resembles the disease-causing microorganism and is often made from weakened or killed forms of the microbe, its toxins, or one of its surface proteins.
How does it work?
A vaccine works by training the immune system to recognise and combat pathogens, either viruses or bacteria. To do this, certain molecules from the pathogen must be introduced in the body to trigger an immune response. These molecules are called antigens and they are present on all viruses and bacteria.
By injecting these antigens into the body, the immune system can safely learn to recognise them as hostile invaders, produce antibodies, and remember them for the future. If the virus or bacteria reappears, the immune system will recognise the antigens immediately and attack aggressively well before the pathogen causes sickness.
Vaccines for Covid-19 being developed around the world:-
Russia is all set to register the world’s first corona vaccine on the 12th of August,2020.
This is an adenovirus-based vector vaccine which is combined with the spiked protein of SARS-CoV-2 virus to induce an immune response in the body.
India is currently in the clinical trials for 2 vaccines:-
i) Bharat Biotech’s COVAXin – This vaccine contains a part of the virus instead of the whole. It is an inactivated vaccine with alum as an adjuvant to boost immune response and increase its efficacy.
ii) Zydus Cadilas’ ZyCoV-D – It is a DNA vaccine in which researchers first obtain plasmids from a bacterium and then separate some genetic material from the virus and then insert it into the plasmid. Then this plasmid is injected into the body to elicit an immune response.
Vaccine in the UK:-
Developed by the University of Oxford in collaboration with AstraZeneca, the vaccine contains a virus which is a weakened and non-replicating version of a common cold virus (adenovirus) which has been engineered to express the SARS-CoV-2 spike protein.
Vaccine in the USA:-
Developed by a US-based company, Moderna, the vaccine is an mRNA based vaccine which instead of introducing protein drugs into the body, drugs trigger cells to produce the required proteins to fight off the infection.
Vaccine in China:-
Developed by the Wuhan Institute of Biological Products and Sinopharm, the vaccine contains an inactivated form of coronavirus to trigger an immune reaction.
Another vaccine CORONAVac is also an inactivated coronavirus vaccine.
With tens of hundreds of countries and pharma companies in the race for developing their own coronavirus vaccine, the WHO is urging countries to join their venture called COVAX.
For the vast majority of countries whether they can afford to pay for their own doses or require assistance, COVAX means receiving a guaranteed share of doses and avoiding being pushed to the back of the queue as we saw in the H1N1 Pandemic.
Till then, Stay Home, Stay Safe!
Featured Image Courtesy – India Today