Vaccination for Viral Diseases

The past year has seen unprecedented happenings, bringing life to a halt. The unable things happened. The humans were stopped right in their tracks, and everyone felt powerless. The COVID 19 pandemic not only has resulted in financial losses worldwide, but it had also led to the death of about 51 lakh people worlds Though it had happened in the past when viral infections caused widespread death, in the modern era, no one even imagined that a virus could bring humanity to a halt. Viruses cause many diseases, some of which can cause death, while others can cause severe debility. The majority of diseases caused by viruses attack infants and young children, but it affects people of all ages. One of the most effective methods for preventing death and disability from several viral illnesses is vaccination. Conclusion: There are a variety of vaccines that are both effective and safe, which help prevent diseases caused by viruses that can cause deaths, hospital admissions, and further consequences. Edward Jenner was the first person in modern-day history to have used cowpox material to induce immunity to smallpox way back in 1796. However, some evidence does exist that the Chinese employed smallpox vaccination as early as 1000 CE. It was also practiced later in Turkey and Africa.


INTRODUCTION
The past year has seen unprecedented happenings, bringing life to a halt. The unable things happened. The humans were stopped right in their tracks, and everyone felt powerless. The COVID 19 pandemic not only has resulted in financial losses worldwide, but it had also led to the death of about 51 lakh people worlds Though it had happened in the past when viral infections caused widespread death, in the modern era, no one even imagined that a virus could bring humanity to a halt [1]. Viruses cause many diseases, some of which can cause death, while others can cause severe debility. The majority of diseases caused by viruses attack infants and young children, but it affects people of all ages. One of the most effective methods for preventing death and disability from several viral illnesses is vaccination. There are a variety of vaccines that are both effective and safe, which help prevent diseases caused by viruses that can cause deaths, hospital admissions, and further consequences [2].

HISTORY OF VIRAL ILLNESSES AND PANDEMICS
The story of vaccination did not begin with the first vaccine; it began long ago when humans started suffering from infectious diseases. Humans

VACCINES AND A BRIEF OVERVIEW
Vaccination and immunization are done routinely for infants and children, and almost every country has a vaccination schedule.
The WHO started the universal program on immunization in 1974. Less than 5% of the world's children under one year of age were immunized against deadly viral diseases like Polio, Measles, and Pertussis. Currently, a rough estimate states that 83 % of the world's children under one year of age receive vaccines against these diseases. New vaccines against hepatitis A and B are slowly being included. Still, one-fifth of the world's children, around 22.4 million infants, are not immunized against these diseases. It is estimated that about 1.5 million children died from vaccine-preventable diseases in 2011 which could have been prevented if universal vaccination had been used [4].

WHAT IS A VACCINE
A vaccination is a biological preparation that boosts your immune system against a particular disease. A vaccination is made up of components that resemble the microorganisms that are responsible for infectious diseases. They are made from the microbe's killed forms or toxins or one of the antigens. Sometimes live viruses are used, modified to have lost their infectivity but retain their immunogenicity. The agent incites the body's immune mechanism to recognize the agent as foreign. Then bodies immunity destroys the infectious agent on coming in contact with it. The body's immune system also develops memory against the microorganism so that the immune system can more easily recognize and quickly destroy microorganisms on further encounters [5].

HOW DO VACCINES WORK
Vaccines hold weakened or inactive antigens, which initiate an immune response in the body. The body will create antibodies to combat the disease, whether the vaccination consists of the antigen itself or the blueprint. The live virus vaccine contains a weakened version, which will not cause the disease in the person receiving the vaccine but initiate an immune response. The response to virus exposure is similar to what would have happened in the body if it was exposed to the disease-causing microorganism.
Some vaccines require multiple doses, whereas booster doses are given weeks or months apart. These booster doses are needed to facilitate development of long-lived antibodies and memory cells in the body. In this manner, the human body is aligned to offset the specific disease-causing organism, which builds up the memory of the pathogen such that a rapid response is readily available to fight the infectious agent in coming times [6].

ROUTES OF ADMINISTRATION
The vaccines can be administered either orally, intramuscularly, sub-cutaneous, or by the intradermal route. Also, vaccines can be given through intra-nasal route for e.g. influenza vaccine.
Vaccination program has led to the eradication of many viral diseases like small pox, one of the most infectious and deadly disease. It has also led to control of many viral diseases like measles, mumps, rubella, polio and chicken pox [9].
India has its own immunization program, few of the salient points of which are as

FUTURE AND CHALLENGES
Immunization agenda 2030 {action plan} Protein subunit vaccines are being rapidly included as the future of vaccination. They take a different method to stimulate the immune system which differs from the mRNA and DNA Covid-19 vaccines. This method incites our immune system by offering a part of the virus that is incapable of causing disease. In recently concluded clinical trials, protein subunit vaccines have shown very good efficacy in protecting against Covid-19. They are also more stable and do not require the maintenance of strict cold chain. Thus, making them easier to distribute among remote areas.

ADVANCES IN ADJUVANTS
Adjuvants help generate an added immune response, allowing the use of less dose of vaccine to generate the same level of protection, This ultimately increases the number of doses that can be made which is useful when the entire humanity needs vaccines to fight the same virus at the same time [14-19].

CONCLUSION
Immunization is a long-term investment that will result in a healthier, safer, and more prosperous society for everyone.