first_imgThere is a phrase in Hindi as “जहरको जहर मारता है।” and basically vaccines are being developed on the same principle. As the vaccines are generally produced by using the pathogen that caused the infection and disease such as virus and bacteria. Thus, vaccines develop immunity by imitating an infection that rarely causes illness. This helps the body to produce antibodies to acquire required immunity against the respective disease. In general, vaccines generate an immune response, which will protect the vaccinated person during future exposures to the disease. However, some person failed to generate the required antibodies after immunization due to some problem with their immune system.There are different types of vaccines such as attenuated vaccines, inactivated vaccines, toxoid vaccines, subunit vaccines, conjugate vaccines. Recently much effort is going on in the production of molecular genetic knowledge-based vaccines. Attenuated vaccines contain a version of the living virus or bacteria that has been weakened. As attenuated vaccines are the closest thing to a natural infection that helps in the development of specific antibodies to develop required immunity. However, attenuated vaccines do not cause serious disease in people with healthy immune systems. Inactivated vaccines are made by inactivating, or killing, the virus or bacteria. However, in the case of inactivated vaccines, multiple doses are necessary to develop immunity. Toxoid vaccines made of weakened bacterial toxins, so they cannot cause illness and develop specific antibodies. Whereas subunit vaccines include only parts of the virus or bacteria, or subunits, instead of the entire germ. As the subunit vaccines contain only the essential antigens, and thus, the side effects are less common. Conjugate vaccines fight a different type of bacteria where antigens have the outer cover that make it difficult for the immune system to recognize it and respond to it. The molecular genetic knowledge-based vaccines come under personalized and predictive medicine. This type of approach provides patients with a specific treatment taking into account their particular genetic profile and molecular phenotype (observable characteristics). As the immune responses induced by vaccines vary according to gender, age, co-morbidity (more than one disorder), immune system, and genetic background. It is thought that the molecular genetic approach will overcome the obstacles of the conventional methods of vaccine development.However, the known history of immunization goes back to the 17th century as the Buddhist monks from China used to drink snake venom to get immunity from a snake bite. Edward Jenner first time use the concept of the vaccine as the inoculated a 13 year-old-boy with cowpox virus in 1796, which resulted in the immunity to smallpox. Thus, the first smallpox vaccine was developed in 1798. And the systematic implementation of mass smallpox immunization that achieved its global eradication in 1979. The credit for the development of live attenuated cholera vaccine (1897) and inactivated anthrax vaccine (1904) goes to Louis Pasteur. Similarly, the credit for the development of Inactivated vaccines goes to Alexander Glenny (1923). The work of these people initiated several R&D efforts in the development of vaccines to prevent different diseases.  However, no vaccine is 100% effective, but it varies from disease to disease. For instance, after receiving the second dose, almost 99.7% of MMR (measles, mumps and rubella) vaccinated individuals become immune to measles. The inactivated polio vaccine offers 99% effective after three doses. Whereas the chickenpox vaccine is almost 100% effective in preventing moderate and severe chickenpox.However, irrespective of several efforts there are still no effective vaccines against viruses that caused the disease such as flu, malaria, tuberculosis, HIV, cancer, etc. As it is very difficult to identify the exact piece of an antigen that may trigger the production of the required antibody. And sometimes, irrespective of the presence of vaccines, body cells failed to rearrange themselves at the molecular level that required for the production of specific antibody. In case of flu, the virus strains keep on changing and that need new vaccine each time to get the protection. There are other efforts of injecting antibodies directly and that has shown some positive results. However, generally, the life of an antibody is around 21 days and thus, one has to keep on injecting antibodies to achieve protection against the respective disease. There is a possibility to reprogram body cells to produce the required antibody using molecular genetic knowledge of that person. However, compared to the conventional vaccine, the personalized vaccine may cost higher and may be out of common people’s reach. However, the R&D efforts in this direction may come up with a personalized vaccine.So far, effective vaccines are available for the infection/disease such as Diphtheria; Tetanus; Pertussis; Measles; Mumps; Rubella; Polio (IPV); Hib (infant meningitis); Hepatitis B; Varicella; Hepatitis A; Pneumococcal; Influenza; Rotavirus. However, irrespective of some shortcomings, vaccination has acted as a miracle in the protection of human/animals against different viral or bacterial infection. The efforts of people like Edward Jenner, Louis Pasteur, Alexander Glenny have created this miracle. However, we do not find time to even say “Thanks” to them and remain busy in settling the economic score. This may be the reason as we forget irrespective of having a knowledge of the SARS-CoV in 2003, and allow COVID-19 to sacrifice millions. Hopefully, we will be able to develop an effective vaccine to protect people from COVID-19 infection. As the genetic data of SARS-CoV is already available and how it has been converted into COVID-19 within almost 16 years, the R&D efforts will find out. This may help to identify the exact molecular portion responsible for the production of antigen that may help in the development of an effective vaccine. However, the current trends suggest that the COVID-19 infection recovery rate is significantly higher than the death rate. That means the production rate of antibodies against COVID-19 infection is higher and that is the positive sign. Thus, there is no need to panic, we need to follow the prescribed protective measure to come out safely. However, it will be better if we keep on concentrating on the improvement of our natural immunity using our respective traditional diet to fight COVID-19. Unfortunately, the most worrying part is the COVID-19 infection of health and security professional at an alarming rate. There is an urgent need to develop a practical and effective protective measure that can avoid “Saviour to become Victim”. Hopefully, we may be able to keep the overall damage at a minimum with the help of experts.last_img

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