Adolescent vaccines: Need special focus in India

Abstract

WHO defines adolescence age between 10 to 19 years. In India, there are 243 million adolescents which constitute 21 per cent of the total population. The global burden of disease in adolescents (2011) reports that the total number of disability adjusted life years (DALYs) worldwide among adolescents were 230 million which constitutes 15.5% of total DALYs. The immunization is one of the most important, most beneficial and cost-effective disease prevention measures that can be provided for adolescents. The adolescent vaccination protects most of the world's adolescents from a number of infectious diseases that previously claimed millions of lives each year. In India, thousands of adolescents die and thousands are hospitalized every year due to communicable diseases that could have been prevented by vaccination. Main aims of adolescent vaccinations are: to boost immunity status that is waning after completion of primary immunization or absence of “natural” boosting due exposure to the particular disease. The recommendations for the immunization of adolescents are to improve vaccination coverage among them. The adolescent vaccinations also help in accelerate disease control or elimination effort. Improvement in adolescent immunization coverage in India, will require strengthening of health care delivery system and also require significant improvements in the health care functionaries ability and willingness to provide and deliver vaccines to adolescents.

Keywords:

• adolescence
• disability adjusted life years
• control
• elimination
• vaccination

Adolescent Vaccines: Need Special Focus in India

WHO defines adolescence as the second decade of life, between the ages 10 to 19 y old age. In India, there are 243 million adolescents which constitute 21 per cent of the total population. In absolute numbers, more adolescents live in India than any other country. It is followed by China, with around 200 million adolescents. This sheer number itself is a big challenge in itself. Of the total adolescent, 12% belong to the 10–14 y age group and nearly 10% are in the 15–19 y age group.¹ The global burden of disease in adolescents (2011) reports that the total number of disability adjusted life years (DALYs) worldwide among adolescents were 230 million which constitutes 15.5% of total DALYs.² Vaccine coverage in adolescents is inadequate because in general they have less contact with physicians than younger children, many lack access to health care, and opportunities to vaccinate are missed by the provider. In addition, because adolescence is a time for exploration and experimentation, adolescents engage in high-risk activities that increase their risk for various infectious diseases, such as hepatitis B and human papillomavirus (HPV). Three important infections (Neisseria meningitidis, Pertussis and HPV), for which effective vaccination now is available, are especially prevalent in the adolescent years, making the adolescent age group the ideal target age for prevention.³

Pertussis has not been eliminated from any country despite decades of high vaccination coverage. The resurgence has been reported from some high-coverage countries including the Netherlands, Belgium, Spain, Germany, France, Australia, Canada, and the USA. Incidence reported in adolescents and adults range between 300 to 500 per 100 000 person-years in several countries.⁴ Evidence has shown that adults play an important part in passing infection to young infants.^5,6 Until recently, diphtheria was a rare disease in industrialized countries with well-established routine childhood vaccination programs. Following primary vaccination, however, anti-diphtheria antibodies wane in the absence of boosting either by natural exposure or through administration of booster vaccination. Waning of antibodies in adults has been documented in various studies in Australia, New Zealand, Germany and Poland.^7-11 Appropriate evidence exists for the boosting of tetanus, diphtheria and pertussis throughout life.^12-14 The International Consensus Group on Pertussis Immunization has advocated pertussis boosting of all age groups.¹⁵

Hepatitis A vaccine is indicated for all children at 12 mo age. Adolescents who are at increased risk of acquiring hepatitis A or at increased risk of severe disease from hepatitis A infection also should be immunized. This includes adolescents who travel internationally to areas where hepatitis A is endemic, male adolescents who have sex with men, those who use illegal drugs, those with clotting factor disorders, and those with chronic liver disease. Routine annual influenza vaccination is recommended for all individuals aged ≥6 mo. Thus, all adolescents should be immunized annually with influenza vaccine. Particular focus should be on the administration of vaccine for adolescents who have underlying medical condition associated with an increased risk of complications from influenza, as well as for adolescents who have contact with high-risk persons like asthma or other chronic pulmonary diseases, hemodynamically significant cardiac disease, immunosuppressive disorders or therapy, hemoglobinopathies including sickle cell anemia, chronic renal dysfunction, human immunodeficiency virus infection, chronic metabolic disorders such as diabetes mellitus etc.³

Mostly persons infected with Hepatitis B in the young adult or adolescent age. Hepatitis B vaccine is effective at any age and it is given through routine national immunization schedule, but if this vaccine given prior to exposure, it can prevent infection in almost all individuals, and will reduce cancer of liver later in life.^16,17 However, any reduction in HBV- related liver disease resulting from universal vaccination of infants cannot be expected until vaccinated children reach adolescence and adulthood.¹⁸ Government of India had recommended Hepatitis-B vaccine as part of routine immunization in 33 districts and 15 metropolitan cities¹⁹ in 2002, and now Hepatitis-B vaccine is given in the whole country.²⁰

The strategy of the World Health Organization (WHO) for the elimination of measles and rubella says that all infants be administered the MMR vaccine, while special precaution be taken to ensure that all girls in the adolescent or marriageable age (who might not have received MMR vaccine in infancy) are protected with rubella vaccine. The MMR vaccine, though widely administered to infants since 1985, is still not part of the Universal Immunization Programme of the nation. However, Delhi, Sikkim, Puducherry and Goa have included the vaccine in their routine immunization program as a state-level initiative.

The immunization is one of the most important, most beneficial and cost-effective disease prevention measures that can be provided for adolescents. The adolescent vaccination protects most of the world's adolescents from a number of infectious diseases that previously claimed millions of lives each year. In India, thousands of adolescents die and thousands are hospitalized every year due to communicable diseases that could have been prevented by vaccination. Main aims of adolescent vaccinations are: to boost immunity status that is waning after completion of primary immunization or absence of “natural” boosting due exposure to the particular disease. The Scientific Advisory Group of Experts (SAGE) has indicated to Expanded Programme of Immunization (EPI) that there is need to expand immunization activities beyond infancy especially to adolescents. The adolescent age group represents an important additional target group. The success of EPI have led to a rise in the average age of incidence of its targeted diseases, which has made unprotected adolescents more vulnerable to these diseases and very rightly have further increased the importance of immunization in Adolescents.²¹

The recommendations for the immunization of adolescents are to improve vaccination coverage among them. The adolescent vaccinations also help in accelerate disease control or elimination effort e.g., measles elimination in certain countries has targeted individuals from 9 mo to 14 y. The immunization for adolescents counter a specific risk e.g., adolescents is the period of taking the risk like intravenous drug abuse or sexual experimentation with a number of partners may get chance of getting hepatitis B and C virus infection (Table 1).

Table 1. Indian Academy of Pediatrics recommends following schedule for adolescents²²

Vaccine	Recommended age of vaccination
Tdap/Td	Tdap is always preferred over Td at the age of 10 y followed by repeat Td every 10 y only when an adolescent immunized earlier with 3 doses of DPT below 1 y and booster at the age of 1^1/2 years and at 5 y
MMR	1 dose at 12–13 y of age, if not received earlier
Rubella	1 dose to girls at 12–13 y of age, if MMR or rubella is not given earlier
Hepatitis B	3 doses at 0, 1 and 6 mo, if not received earlier
Hepatitis A	2 doses at 0 and 6 mo,
Typhoid	Single dose intramuscular Vi polysaccharide or 3 doses of oral typhoid vaccine on alternate day empty stomach. Booster is given every 3 y
Varicella	1 dose up to 2–12 y and 2 doses after 12 y of age
HPV	Only for girls at the age of 10–12 y with 3 doses schedule either 0, 1, 2 or 0, 1, 6 mo depending upon the vaccine used

Improvement in adolescent immunization coverage in India, will require strengthening of health care delivery system and also require significant improvements in the health care functionaries ability and willingness to provide and deliver vaccines to adolescents. The ministry of health and family welfare, government of India should make the policy for adolescent vaccination and community at large need to be made more aware about the value of adolescent immunization. There is need to strengthen the other areas like health care quality measures, quality surveillance and research.

Disclosure of Potential Conflicts of Interest

No potential conflicts of interest were disclosed.