Vaccines for children may be broadly classified as Essential (EPI) vaccines included in national immunization schedule – BCG, OPV, DPT, Measles and Hepatitis B, Recommended or Optional vaccines e.g. MMR, H. influenza B, Typhoid, Hepatitis A, Varicella, Vaccine for selective use e.g. High-risk children: Pneumococci, Meningococci, influenza virus Post-exposure: Anti-rabies vaccine and Combination Vaccines & Newer vaccines.
ESSENTIAL (EPI) Vaccines for children
National immunization schedule in India include routine vaccination of all children with five vaccines i.e. BCG, OPV, DPT, measles and HBV*, against seven major vaccine preventable diseases (VPDs) i.e. tuberculosis, diphtheria, pertusis, tetanus, poliomyelitis, measles and hepatitis B. These vaccines for children are supplied free of charge by the Government.
* HBV i.e. Hepatitis B vaccine has been included in national immunization schedule from inuary I 2004.
BCG vaccine is the oldest of all the vaccines.
DPT (Triple vaccine) is a combination vaccine against three diseases – Diptheria, Tetanus and Pertusis.
Oral polio vaccine (OPV): 2 types of polio vaccines are in the market – a live, oral, Sabin vaccine and an inactivated, parenteral Salk vaccine, named after their developers.
Salk vaccine (IPV) is an inactivated cum heat-stable and polyvalent vaccines for children, containing all three seotypes. Though as protective as Oral Polio Vaccine, the mode of immuno-protection is distinct (local immunity in OPV vs. systemic immunity in IPV).
Measles vaccines for children is available either as a single disease vaccine or in a combination with mumps and rubella.
MMR vaccine are a combination of mumps and rubella shots.
Hepatitis B vaccine (HBV) has been recently included in MS since Anuary 1, 2004. Presently, 2 types of HBV are available that are plasma-derived and recombinant DNA vaccines, and both are equally effective, safe and interchangeable for different doses in same child.
RECOMMENDED & OPTIONAL Vaccines for children
Recommended & Optional vaccines are those vaccines, which are desirable in all children, though current logistics and cost-factor preclude their inclusion in the national immunization schedule.
These vaccines for children are not supplied by the government and have to be bought by parents. However Being an optional vaccine does not lessen the importance of vaccine.
Indian Academy of Pediatrics (lAP) has recommended inclusion of some of them e.g. Typhoid, MMR and HIB vaccines in National immunization program, while others e.g. HAV & varicella vaccines may be given after one to one discussion with parents.
Typhoid vaccines for children are of 3 types
a) Whole-cell inactivated vaccines,
b) Live attenuated oral vaccine (Ty2 1 strain), and
c) parenteral Vi capsular polysaccharide vaccine.
H. Influense B (HIB) Vaccine: HIB infection is one of the leading cause of pneumonia and meningitis in infants and toddlers, though the incidence declines with advancing age and uncommon beyond 5 years.
Although considered as an essential vaccine by lAP for all children, high cost prohibits its inclusion in NIS. Currently, it is recommended as an optional for all affording children as well as essential for high-risk children with splenic dysfunction e.g. splenectomy, sickle cell disease, nephrotic syndrome etc.
Hepatitis A Vaccine (HAV): Although hepatitis A is a common infection, universal HAV immunization is not recommended due to relatively benign nature of disease. It may be offered as an optional vaccination to all affording children/adolescents without preceding natural disease or in high-risk cases.
Varicella vaccine: Although Varicella is a common and highly contagious infection, these vaccines for children is not recommended for universal immunization due to relatively benign nature of disease in childhood. It may be offered to all affording children/adolescents without previous disease or in high-risk cases.
Vaccines for children FOR SELECTIVE USE
These vaccines are not recommended for routine immunization, but only in high-risk children. Discussed in relevant chapters, some important selective-use vaccines are as follows —
a) Anti-rabies vaccine (ARV) is used for post- exposure prophylaxis after dog-bite or pre-exposure prophylaxis to occupational animal handlers.
b) Pneumococcal vaccine is indicated in cases with — a) splenic dysfunction e.g. asplenia, splenectomy, sickle cell disease, b) chronic lung/heart disease, c) nephrotic syndrome, and d) CSF-leak states,.
c) Meningococcal is indicated during epidemics, in close and locality contacts of an index case, along with chemoprophylaxis.
d) Influena vaccine is indicated in cases with — a) chronic lung/heart disease, b) immunodeficiency states, and c) community-living e.g. orphanages.
e) Cholera vaccine: Considering high risk of side effects, poor protective value and short-term efficacy, these vaccines for children is rarely used except during epidemics, large human congregations e.g. Kumbhs, or to fulfill travel requirements for some countries.
1) Yellow fever vaccine is a live attenuated vaccine containing viral strain 17D, given to fulfill the international travel requirements for some African/ South American countries, as single dose 0.5 ml SC. Efficacy is 100% for 10 years. Vaccine carries a significant risk of post-vaccine meningoencephalitis.
g) Japanese encephalitis vaccine is a mouse-brain, inactivated vaccine using either Beijing or Nakdyarna strain (used in India), with protective efficacy of — 90% for two years.
At present only limited supply of these vaccines for children is available from central research institute, Kasauli (HP), supplied only to the government.
Although erroneously used during epidemics, It is not an outbreak-response vaccine. TAP recommends it use for universal immunization of all children above one year in hyper-endernic districts of country, given as – Three primary doses on day 0, 7 and 28 (0.5 ml SC < 3 years, 1.0 ml SC >3 years) with boosters every two years.
h) Rotavirus, recently available in India, is a oral live attenuated vaccine derived from RIX 4414 strain, given as two doses at 2 & 4 months. Vaccination should be complete before 6 months of age. The protective value is > 78.5% for diarrhea and > 95% for severe diarrhea. Potential risk of intussception, reported with earlier rotavirus vaccine, is extremly low with current vaccine.
NEWER vaccines for children
Newer vaccines is a loosely-defined and dynamic term encompassing large number of vaccines that include —
a) Recently available optional vaccines e.g. influenza vaccine,
b) Modified versions of existing vaccines with better immunogenicity and safety e.g. DTaP,
c) Combination vaccines, and
d) Vaccines under development.
Combination vaccines for children: Many new combination vaccines are available at present, along with OBS: Group B streptococci, ETEC: Enterotoxigenic E.coIi, HSV: Herpes simplex, cMv; cytomegalovirus, RSV: Respiratory syncitial virus
* combination vaccines. # but available as government supply.
Older ones e.g. DPT, DT and MMR vaccines, routine used in India. The main aim of these vaccines for children is to reduce the number of pricks and hospital visits for immunization and TAP recommends their use with following caveats —
a) Combination vaccines, although convenient, are no way more effective than isolated vaccines.
b) Indigenous mixing of separate vaccines for children in the same syringe, prior to injection, to make a combination vaccine, should be discouraged.
c) The manufacturer’s recommendations should be strictly adhered in case of combination vaccines for children.