Vaccine and vaccination have been on top of everyone’s mind, especially during the last year when the COVID-19 pandemic ravaged economies worldwide. Now, with two vaccines in India being approved by the Drugs Controller General of India (DGCI), the nation is well on its path to start one of the world’s biggest vaccination drives. So, what is vaccination, its importance, types, and other aspects? Let’s find out.
Vaccination is a process of protecting people against various diseases. Through it, resistance is built against specific infections, and it makes the immune system stronger. Vaccines administered create antibodies that protect people when they are exposed to a particular disease. While most vaccines are given through an injection, some are given orally.
Kids generally have a weak immune system and they need vaccination to protect themselves against serious complications that can even result in hearing loss, paralysis, amputation of arm and legs, among others. Several ailments such as measles, mumps, and whooping cough are vaccine-preventable.
In other words, vaccination can help prevent these diseases in children. Also:
It’s essential to note that vaccination is not only essential for kids but also for adults. For instance, several vaccines such as Hepatitis B, HPV, and Flu lower the chances of adults being diagnosed with liver cancer, cervical cancer, and flu-related heart attacks. Hence, even adults, along with kids, should get themselves vaccinated on time.
This vaccine injects the live version of the virus that causes the disease. Though live, the version is weakened, and as a result, cannot multiply and cause infection in the body.
Live-Attenuated vaccines are commonly used to build immunity against diseases caused by viruses and works by reproducing memory B-cells that remember the virus and generate an immune response against it. Through this vaccine, you generally get lifelong immunity and on most occasions, one to two doses of this vaccine is administered.
A live-attenuated vaccine is used to provide protection against diseases such as rotavirus, smallpox, chickenpox, yellow fever, measles, mumps, and rubella, among others.
This type of vaccine uses the strain of the virus or bacteria that’s dead. One of the earliest types of vaccines, the immune response triggered by inactivated vaccines is generally weak compared to a live-attenuated vaccine.
Also, this vaccine doesn’t provide lifelong immunity and needs topping over time. The vaccine is used to build immune responses against polio, rabies, flu, and hepatitis A.
This vaccine when administered triggers an immune response using antigens from the surface of the virus or the germ. Composed of protein and glycoprotein, they isolate certain antigens that are chosen as per the strength of the immune response they generate.
In this vaccine, the gene creating the protein for the virus or bacteria is isolated, and then it’s inserted into the genes of another cell. When that particular cell reproduces, vaccine proteins are made to protect the body against that specific virus or bacteria.
This vaccine consists of two components. It combines a weak antigen with a stronger one for the immune system to trigger a strong response. Covalent attachment of the weak antigen to the strong one elicits a more robust immunological response.
Using polysaccharides or sugar molecules from the outer layer of the virus or bacteria, this vaccine stimulates B-cell responses resulting in the production of specific antibodies that kill the pathogens.
This vaccine uses a toxin made by the germ, causing the disease to create immunity. Note that the immunity is created to parts of the germ instead of the whole germ. This vaccine is used to protect against diphtheria and tetanus.
Two new types of the vaccine under development the DNA vaccine includes DNA creating certain antigens from the germ. Once administered, the body reproduces the germ’s DNA that is recognised by the immune system for further protection.
On the other hand, recombinant vector vaccines train the immune system to recognise and attack the germ. They work through the reproduction of live virus engineered to carry extra genes from the germ, causing infection.
One of the most widely used vaccines in India and across the globe, the BCG or Bacillus Calmette Guerin vaccine is given to prevent tuberculosis. French bacteriologists Albert Calmette and Camille Guérin developed this vaccine over a period of 13 years, from 1908 to 1921.
This vaccine is administered to prevent polio that affects the body’s nervous system. American physician Jonas Salk developed the first polio vaccine in the early 1950s. In 1960s, American physician and microbiologist Albert Sabin developed the second type of polio vaccine known as oral polio vaccine (OPV).
American physician and geneticist Dr Baruch Samuel Blumberg discovered the Hepatitis B vaccine in 1965 and bagged the prestigious Nobel Prize for his discovery. Note that Hepatitis B is the first anti-cancer vaccine as it helps in the prevention of liver cancer.
The Pulse Polio Immunisation Programme is one of the most important vaccination drives undertaken in India. It was launched in 1995 after the World Health Organisation (WHO) adopted a resolution in 1988 to eradicate polio globally.
Every year, under this programme, children in the age group of 0-5 are given polio drops, and booths are set up across the nation. Volunteers and vaccines are arranged, and on national immunisation days, children are administered the oral polio vaccine.
There’s extensive publicity with advertisements in print and electronic media. Celebrities are roped in to advertise so that no children in the country gets deprived of vaccination. Also, under this programme, rapid response teams (RRT) have been deployed by all states and union territories to respond to any polio outbreak in the country.
States have also developed Emergency Preparedness and Response Plans (EPRP) that indicate steps to be taken in case any case of polio is detected. Additionally, under the programme, OPV is mandatory for those travelling from polio-affected nations.
In recent times, if there’s one vaccine that has been in the news, it’s the one developed to combat the novel coronavirus that has claimed many lives in India and across the globe. In 2021, the Drugs Controller General of India (DCGI) approved two COVID-19 vaccines for restricted emergency use – Covishield and Covaxin.
Though the primary goal of these two vaccines is the same, there are a few differences. Given below is the comparison of both these vaccines on several parameters:
Covishield has been developed by Oxford University in collaboration with pharma company AstraZeneca. Serum Institute of India is manufacturing this vaccine in India.
On the other hand, Bharat Biotech has developed Covaxin in collaboration with the Indian Council of Medical Research (ICMR).
Scientists have made Covishield by using adenovirus, one that causes common cold infection in chimpanzees. The genetic material is identical to the spike protein of the coronavirus. This vaccine has used the weakened version of adenovirus.
Covaxin has been made using dead coronavirus. When injected, the vaccine prepares the immunity system in a manner so that it recognises the actual virus and helps the body fight it.
While the efficacy rate of Covishield is said to be more than 70%, the rate is yet to be published for Covaxin that is in the final stage of clinical trials.
Both Covishield and Covaxin needs to be given in two doses. Also, both these vaccines are easy to store and can be kept at 2-8 degrees Celsius. This makes it extremely easy to store and transport them across all parts of the country.
Vaccination is an essential cog in the wheel in our collective efforts to fight various diseases. We must get vaccinated on time and also encourage and help others to do so. Also, during vaccination, we must all co-operate with authorities so that the entire exercise goes without a hitch.