When Edward Jenner first administered smallpox vaccine in 1796, the process was known as variolation. Later came the terminology, ‘vaccination’, which was widely accepted. The term ‘immunization’ came into vogue in due course to emphasize the importance of active immunity induced by various antigens. The Greek word Immune means to be protected. Whereas the protection offered by vaccines is ‘active’, passive protection is achieved by the administration of antisera or immunoglobulins. So certain terminologies need to be defined carefully. Today both the terms ‘vaccination’ and ‘immunization’ are used interchangeably. However, the global practice is to use the term ‘immunization’ more frequently viz, Expanded Program on Immunization (EPI), Universal Child Immunization (UCI), Global Alliance on Vaccines and Immunization (GAVI) etc.
After the discovery of smallpox vaccine in the year 1796, it took 79 years, for Louis Pastuer to develop the killed rabies vaccine in 1885. Then came the discovery of many more monovalent childhood antigens and the discovery of the first combination vaccine DTP in 1945 and measles, mumps and rubella combined vaccine in 1971. With advances in genetic engineering and molecular biology the future will witness the development of more newer antigens and perhaps most of these newer antigens will be in combination formulation.
Apart from the currently available toxin based, subunit, live organisms, inactivated organisms, polysaccharide, glycoconjugate vaccines, etc. we will be having additional or replacement vaccines viz., anti-idiotype vaccines, re-assorted genomes, temperature sensitive mutants, recombinant viruses and bacteria, recombinant viral or bacterial vectors, genetic (DNA), plant (edible) vaccines, and transcutaneous vaccines which will revolutionize the concept of immunization.
In addition to development of new vaccines, new vaccine implementation and delivery strategies along with new developments in basic and applied science, including those directly related2 to vaccine biotechnology applied implementation research and the bioethics of clinical trials promise to make the 21st century exciting for vaccinology. Developments such as whole genome sequencing may reveal entirely new paradigms for vaccine development. As molecular medicine exorably advances, parallel research must progress to ensure that the scientific advances of high income countries are available to low income countries, as well.
Immunization has rightly been claimed as the greatest success story in the history of mankind in the 20th century. Eradication of smallpox in 1978 had paved the way for the elemination/eradiaction of similar vaccine preventable diseases in several developed countries. Many developing countries like India too, have achieved outstanding success in eliminating VPDs like neonatal tetanus, diphtheria, pertussis, measles, etc. global eradication of poliomyelitis is expected to be achieved by 2010.
Following repeated representations from the Indian Academy of Pediatrics, the Government of India has constituted a National Technical Advisory Group on Immunization (NTAGI) and ‘India Experts Advisory Group (IEAG)’ which will look into the exiting immunization practices and India Polio Eradication Initiative and AFP surveillance respectively and suggest introduction of a few more vaccines into the National Immunization Schedule and strategies to be adopted for polio immunization. It is fervently hoped that the laudable objective of ‘All Vaccines for all the World's Children’ will become a reality in the near future.
The National Technical Advisory Group on Immunization since recommended in 2009 the introduction of MR vaccine in the National Immunization schedule as well as DTPw Booster in place of DT at 5 years. Apart from introducing the pentavalent fully liquid. DTPw – HB-Hib vaccine in 5 selected states viz Karnataka, Kerala, Tamil Nadu, Himachal Pradesh and Jammu and Kashmir where the UIP coverage is > 85%.
The GOI has in principle approved the introduction of pneumococcal conjugate vaccine in the national immunization program with GAVI assistance. Introduction of the Rota virus vaccine is also being contemplated. A campaign approach with a single doss of JE vaccine in JE hyperendemic areas has been successfully implemented. Introduction of MR vaccine at 16 – 24 months along with DTPw booster and Rabella vaccine at 10 years for adolescent girls are also in the agenda.3
SUMMARY
Pediatric and adolescent immunization – yesterday, today and tomorrow
- YESTERDAY:
- Handful of vaccines, Expanded Program on Immunization (EPI), Targeted universal coverage of under 5 children and pregnant mothers, development of combination vaccine formulations, elimination and eradication of VPDs, smallpox eradication achieved.
- TODAY:
- Pocketfull of vaccines, EPI, Universal Child Immunization (UCI), Stress on Adolescent and Adult Immunization, More antigens for immunization during pregnancy, Global Program on Vaccines (GPV), Global Alliance for Vaccines & Immunization (GAVI), development of more combination vaccine formulations, newer adjuvants, newer technologies for vaccine development and administration, vaccine vial monitors to assess cold chain maintenance, elimination and eradication of VPDs, control of neonatal tetanus, diphtheria, pertussis, poliomyelitis and measles achieved
- TOMORROW:Bagful of vaccines, all vaccines for all the world's children with GAVIs subsidy, more sophisticated combination vaccine formulations, needle free vaccine patches, more antigens for universal coverage, improved cold chain equipments, elimination and eradication of more VPDs, global eradication of poliomyelitis, measles and many more
BIBLIOGRAPHY
- John TJ. National Technical Advisory Group on Immunization. Indian Pediatr. 2002; 39:327–330.
- John TJ. Towards an Ideal Vaccination Schedule in India. Indian J Pediatr. 1998;65:S8-S12.
- National Rural Health Mission GOI document Brief overview of Universal Immunization Program in India, ASOV workshop course material, IAP, 2009.
- Parthasarathy A. Sashi N Vani, Walia BNS, National Program on Immunization. In: Parthasarathy A, Menon PSN, Nair MKC, (Eds.) IAP Textbook of Pediatrics (4th edn). Jaypee Brothers Medical Publishers: New Delhi: 2009; 200–202.
- Universal Immunization Program in India. Breaking New Ground. Ministry of Health and Family Welfare, Government of India; 2002; 1–25.
- Widdus R. The Potential to Control or Eradicate Infectious Diseases Through Immunization. Vaccine. 1999;17:S6-S12