Vaccination is an effective, simple, & safe process of protecting people from various harmful diseases. It mainly uses body’s natural defence to build resistance to specific diseases and makes immune system stronger. Vaccines train the immune system to create antibodies, just as it does when it’s exposed to a disease. However, because vaccines contain only killed or weakened forms of germs like viruses or bacteria, they do not cause the disease or put someone at risk of its complications.
Covid-19 pandemic & lockdown together make our daily life hectic & miserable to spend since previous year. In this condition, nearly after 6 months the pandemic, the vaccines are invented. It’s quite similar as oasis in desert to us. Although the vaccines are invented almost 6 months to overcome the various steps of animal trial as well as human trials, the vaccines came in the effective way in the end of 2020.
There are few types of vaccines available all over the world. Among them, Russia’s Sputnik-V vaccine became the first vaccine ever passed the trials with almost 91.6% success rate. There are AstraZeneca by University of Oxford, BNT162b2 by Pfizer- BioNTech, Covishield (Indian version of Oxford-AstraZeneca) & Covaxin from India, Janssen by Johnson & Johnson, Moderna, & recently Remdesivir/ Veklury by Gilead Sciences etc. passed the phases the human trails and also used in the emergency all over the world.
The vaccines may be having some mild side effects varies person to person with some age restriction with some medical history restriction. The vaccines are divided in few categories based on the ingredient & also on the basis of work principle.
India already started vaccination started vaccination drive from the early of 2021. The drive mainly divided in some stages mainly based on age differences. India using their own production Covaxin, Covishield & Remdesivir to produce & increase the immunity against Covid- 19.
Drugs Control Board of India recently approved world’s first vaccine Sputnik-V in the case of emergency uses as some of the states reported to run on shortage on vaccine. It is also expected some more vaccine for emergency uses including Janssen by Johnson & Johnson, Novavax by Serum Institute of India, Nasal Vaccine from Bharat Biotech, Zydus Cadila etc. to produce more immunity.
How do the vaccines work?
India started its vaccination drive from January 16, 2021 based on mainly two vaccines i.e., Covishield or the Indian version of Oxford AstraZeneca & Covaxin, India’s own production by Bharat Biotech. Scientists are divided the vaccines in the following ways.
- Based on RNA
- Based on Viral Factor
- Based on Inactivated Virus
- Based on Protein
The AstraZeneca Vaccine made with the modified version of chimpanzee adenovirus, known as ChAdOx1. It can enter cells through the injection into someone’s arm, but it can’t replicate itself & after the injection this adenovirus bump into cells & latch onto proteins on their surface.
This cell engulfs the virus in a bubble & travels to the nucleus, where the DNA is stored. It eventually produces the required antibody. The antigen presenting cells can also active another type of immune cells known as killer T cell. They always seek & destroy the infected cell, well in this case coronavirus infected cells that display the spike protein fragments on their surfaces.
The Covaxin Vaccine mainly works by teaching the cells of immune system to make antibodies against mainly the Brazil Strain (SARS- CoV-2) of the corona virus. The compound disabled the strain of corona virus by bonding to their genes. The inactivated corona virus can’t no longer replicate itself by evolving their RNA, but their spike proteins remain intact. As the corona viruses in Covaxin are dead, they can be injected through the arm without causing Covid-19.
Once the virus inside the body, some of the inactivated viruses swallowed and destroyed by the immune cell called B cell, which also have surface proteins in a huge variety of shapes, & a few may have the right shape to latch on the corona virus. When B cells locks on the surface, it can pull part or all of the virus inside & present corona virus fragments on its surface.
Once vaccinated with Covaxin, the immune system can respond to an infection of live corona viruses. B cells produce the antibodies that stick to the invaders. Those antibodies target & destroy the spike protein can prevent the virus from entering & effecting the cells. The other kinds antibodies can block the virus by the other working principle.
Scientists put the Covishield & recently approved Sputnik-V in the same category i.e., based on Viral Factor which is also based on the similar working principle & Covaxin in the category of based on inactivated virus & working principle. All the vaccines can be stored in the temperature of 2o to 8o Celsius.
Steps to promote the Vaccination Drive:
From the day of January 16, 2021 i.e., the starting date of India’s Vaccination Drive, till today India became world’s largest vaccination drive & it almost cross 130 million doses so far.
Indian Government divided the vaccination drive in few phases. In the very first phases, the vaccination is strictly restricted to the health workers & frontline staffs. Manish Kumar, a sanitation worker of Delhi got vaccinated on the very first day & became the first Indian to be vaccinated.
In the phase 2, govt. allows the people over age 45 to be vaccinated. The phase 3 will start from May 1, in this phase all above 18 years age are eligible for vaccination, although Indian Government has no plan on vaccination of below 18 years & also for the pregnant ladies with new born babies.
From April 11, Indian Government allows people to get jabs to private & state-run workplaces. The govt. spent almost 5 billion dollars to give free doses at state run clinics, public health centres & hospitals. Serum institute of India is set to sell the vaccines & set the price for the vaccines.
Effects of Vaccine along with Vaccination Drive:
There are some few restrictions for the both vaccines as those vaccines are unavailable for the age below 18 years as well as for those have allergic reactions of the first dose of vaccine as well as ingredients of the vaccines.
Based to trails reports and after vaccination report, doctors divided the side effects in three steps.
Very Common Effects (may affect more than 1 in 10 people)
- Normal Headache
- Pain, swelling at the place of injection
- Feeling unwell, tired
- Joint pain etc.
Common Effects (may affect up to 1 in 10 people)
- Fever, flu symptoms
- Feeling sick (Vomiting, Vertigo) etc.
Uncommon Effects (may affect up to 1 in 100 people)
- Abdominal pain
- Feeling dizzy
- Excessive sweating
- Blood clot at the injection spot etc.
Doctors also suggests if someone having a severe allergic reaction, they can call or go to nearest hospital, in addition they can repot the side effects after vaccination to Serum Institute of India Pvt Ltd.
Despite of the positivity, India so far reported nearly 18,000 adverse events of side effect. Most of them are minor side effect & according to the govt. report all of them had recovered. But there are 617 cases of severe adverse events of side effects, including 180 deaths after vaccination till march.
 Vaccines & immunization: What is vaccination? – WHO
 Different Covid-19 Vaccines- CDC (Dt- April 13, 2021)
 India Clears Way for Foreign Made Vaccines, Wants Applications Soon- NDTV (Dt- April 13, 2021)
 How the Oxford-AstraZeneca Vaccine Works- The New York Times (Dt- March 22, 2021)
 How Bharat Biotech’s Vaccine Works- The New York Times (Dt- March 22, 2021)
 Sputnik-V, Covishield, Covaxin: What we know about India’s Covid-19 vaccines- BBC News (Dt- April 14, 2021)
 Covid-19 vaccination: How is India’s inoculation drive going- BBC News (Dt- April 20, 2021)
 Covid -19: An FAQ factsheet for Covishield Vaccine by Serum Institute- The Economic Times (Dt- January 13, 2021)
Author: Unmesh Roy from National Institute of Technology, Durgapur.