MISSED (CATCH-UP) IMMUNIZATION
Despite best efforts, overall immunization coverage in India for UIP vaccines is ~76% (NFHS-V 2020-21) and substantial number of children miss vaccinations on due ages. To immunize them at earliest possible opportunity, following principles must be followed for catch-up immunization:
[*] Catch-up schedule must be tailored to achieve age- appropriate immunization as early as possible with minimum number of visits but without compromising basic principles, e.g.
minimum dose interval, etc. 
Fig. 9.2: IAP immunization schedule.
a: Within 24 h after birth; b: Extra dose permitted in combination vaccine; c: Can be given as combination vaccine; d: Not required for RV1; e: Preferably pre-monsoon, then single dose annually till 5 years age; f: Single dose for live vaccine; g: Second dose after 3-6 mo; h: After 7 years of age if second DPT booster not received, else single dose at 10-12 years, use Td, if Tdap not available; i: Two doses lt;14 years, 6 mo apart; j: Three doses after 14 years or in immunocompromised persons, k: Menactra® is approved as 2-doses between 9-23 mo at 3 months interval, Menveo® as single dose only after 2 years age
1If last dose was given before 4 years.
2RV immunization should not be initiated beyond 15 weeks of age and all doses must be completed by 32 weeks.
3Exclude pregnancy before vaccination in adolescent girls, due to potentially risk of CRS.
4Pre-Vaccination screening recommended at 10 years.
Multiple vaccines may be clubbed together in same visit to reduce the catch-up time.
• Upper age limit for catch-up immunization varies with the individual vaccines, determined by the need and safety issues and must be strictly followed.
• Partially immunized children should re-start catch-up immunization from the dose which was missed earlier and not afresh, irrespective of the period lapsed.
NIS permits catch-up immunization till the specified age-limits for individual vaccines, i.e. till one year for BCG, PentaV, RV, PCV; five years for OPV, MR; 7 years of DPT booster and 15-16 years for Td and JE vaccine, using same number/s and interval of doses as for routine immunization. These age limits and dosage schedules have been decided for programmatic reasons to cover most vulnerable population with available resources and use a simplified uniform schedule which can be delivered through public resources.
IAP recommendations for catch-up immunization are based largely on scientific basis and hence, might differ from NIS. Upper age limits are usually higher in IAP schedule except for RV vaccines and dosage schedules may differ from those used for routine immunization (Table 9.5).
1Adolescents, who have not been immunized with DPT previously, must receive two further doses of Td at one month and six month interval (0,1,6 month) to complete catch-up vaccination, which is recommended till the age of 18 years.
9.3.4