Learn — Immunisation & cold chain

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National Immunization Schedule

The National Immunization Schedule is the timetable of the Universal Immunization Programme, the Government of India free vaccination service, and it fixes the age, dose, route and site of every vaccine given to an infant, a child and a pregnant woman. It matters because a dose given at the wrong age, by the wrong route or after the wrong interval is a wasted dose and leaves the child unprotected, and because the schedule is the single most heavily examined table in the community health paper.

The Expanded Programme on Immunization began in India in 1978 and became the Universal Immunization Programme in 1985; it now gives free protection against twelve vaccine-preventable diseases, with rotavirus and pneumococcal vaccines extended to all states and Japanese encephalitis vaccine given only in endemic districts.
At birth (institutional delivery or as early as possible): BCG 0.1 mL intradermally into the left upper arm, using 0.05 mL until one month of age; OPV zero dose, 2 drops orally; and the hepatitis B birth dose 0.5 mL intramuscularly into the anterolateral thigh, which must be given within 24 hours of birth.
At 6 weeks: OPV-1 (2 drops oral), pentavalent-1 (DPT with hepatitis B and Haemophilus influenzae type b) 0.5 mL intramuscularly, rotavirus-1 (5 drops oral), fractional IPV-1 0.1 mL intradermally into the right upper arm and PCV-1 0.5 mL intramuscularly; at 10 weeks OPV-2, pentavalent-2 and rotavirus-2; at 14 weeks OPV-3, pentavalent-3, rotavirus-3, fractional IPV-2 and PCV-2.
At 9 to 12 months: measles-rubella first dose 0.5 mL subcutaneously into the right upper arm, the PCV booster, Japanese encephalitis first dose in endemic districts, fractional IPV-3 0.1 mL intradermally into the left upper arm (since January 2023), and vitamin A 100,000 IU as the first prophylactic dose.
At 16 to 24 months: DPT booster-1, OPV booster, measles-rubella second dose, Japanese encephalitis second dose in endemic districts, and vitamin A 200,000 IU, repeated every six months up to 5 years for a total of nine doses; DPT booster-2 is given at 5 to 6 years and Td at 10 years and at 16 years.
A pregnant woman receives Td-1 as early as possible in pregnancy and Td-2 four weeks later, or a single Td booster if she received two Td doses in a pregnancy within the previous three years; tetanus toxoid alone has been replaced by Td in the programme.
A fully immunised child in Indian survey language is one who has received BCG, three doses of DPT or pentavalent, three doses of OPV and the first dose of measles-containing vaccine before completing 12 months of age.
The minimum interval between two doses of the same vaccine is 4 weeks and there is no maximum interval, so an interrupted schedule is resumed from where it stopped and is never restarted; every dose is entered in the Mother and Child Protection card and in the U-WIN electronic immunisation register.

Cold chain

The cold chain is the unbroken system of people, equipment, transport and record-keeping that holds every vaccine within its prescribed temperature range from the manufacturer to the moment it enters the child. It matters because potency lost to heat or to freezing cannot be seen, smelled or restored, so a broken cold chain produces a fully vaccinated register alongside an unprotected population.

The ice-lined refrigerator holds all Universal Immunization Programme vaccines at plus 2 to plus 8 degrees Celsius at the primary health centre and community health centre; the deep freezer at minus 15 to minus 25 degrees Celsius is used only for OPV at higher stores and for freezing ice packs, and walk-in coolers and walk-in freezers serve the state and regional stores.
The freeze-sensitive vaccines are pentavalent, DPT, hepatitis B, Td, IPV, PCV and rotavirus, because freezing breaks the aluminium adjuvant and destroys potency irreversibly; the heat-sensitive vaccines are OPV first, then measles-rubella and BCG, especially after reconstitution.
In a top-opening ice-lined refrigerator the coldest zone is the bottom, so vaccines that tolerate freezing (OPV, measles-rubella, Japanese encephalitis, BCG) go at the bottom of the basket and the freeze-sensitive vaccines are placed above them, away from the floor and walls; diluents are stored with their own vaccine so that they are at the same temperature at reconstitution.
Frozen ice packs must be conditioned before they go into a vaccine carrier, that is left out until water droplets appear on the surface and water can be heard inside, otherwise the freeze-sensitive vaccines sitting against them are ruined; a vaccine carrier takes four conditioned ice packs and is used for a single outreach session, while a cold box takes many more and holds temperature for several days during a power failure.
The vaccine vial monitor is a heat-sensitive square inside a circle on the label: at stage 1 and stage 2 the square is lighter than the circle and the vial is usable, and at stage 3 (square matches the circle) and stage 4 (square darker than the circle) the vial is discarded whatever its expiry date; the monitor records cumulative heat only and never detects freezing.
Freeze damage is detected by the shake test on an adsorbed vaccine such as pentavalent, DPT, Td or hepatitis B: the suspect vial is shaken alongside a deliberately frozen and thawed control, and a vial that sediments quickly leaving a clear supernatant with flakes has been frozen and must be discarded.
Open vial policy: opened multi-dose vials of OPV, hepatitis B, pentavalent, Td, fractional IPV and rotavirus may be used for up to 28 days provided they are kept at plus 2 to plus 8 degrees Celsius, the expiry date has not passed, the vaccine vial monitor is at stage 1 or 2 and the septum has not been submerged in water; reconstituted BCG, measles-rubella and Japanese encephalitis vaccines are discarded four hours after reconstitution or at the end of the session, whichever is earlier.
Temperature is read and entered in the logbook twice a day, morning and evening, on every day of the year including Sundays and holidays, and the alarm condition is acted on at once because it is the record that shows whether the vaccine given last month was potent.

Mission Indradhanush

Mission Indradhanush is the Ministry of Health and Family Welfare catch-up immunisation drive launched on 25 December 2014 to reach every child under two years and every pregnant woman who had been left out or only partly covered by routine immunisation. It matters because full immunisation coverage was creeping up by about one percentage point a year before it, and because its method, namely mapping the missed by name, running planned rounds in the worst-performing districts and following each child up individually, is the standard field method for closing any coverage gap.

The mission was launched on 25 December 2014 and named after the rainbow for the seven vaccine-preventable diseases originally targeted, namely diphtheria, pertussis, tetanus, poliomyelitis, tuberculosis, measles and hepatitis B; the list has since grown with the addition of Haemophilus influenzae type b, rotavirus, pneumococcal and Japanese encephalitis vaccines.
The target group is children up to two years of age and pregnant women who are unimmunised or partially immunised, that is the dropouts, the left-outs and the resistant families, identified by a house-to-house head count and by mapping high-risk settlements such as urban slums, migrant and construction sites, brick kilns, nomadic settlements and hard-to-reach hamlets.
Intensified Mission Indradhanush was launched in October 2017 to push full immunisation coverage above 90 per cent, and successive rounds have run as IMI 2.0 in 2019, IMI 3.0 in 2021, IMI 4.0 in 2022 and IMI 5.0 in 2023, the last of which extended eligibility to children up to five years with a specific focus on measles and rubella elimination.
Each round runs for a block of consecutive days in the chosen districts, typically seven days a month excluding Sundays and gazetted holidays and including the routine immunisation day, repeated over several months, and every session works from a microplan that lists each due beneficiary by name with the mother's mobile number.
Full immunisation coverage among children aged 12 to 23 months rose from 62 per cent in NFHS-4 to 76.4 per cent in NFHS-5 and 82.6 per cent in NFHS-6 (2023-24, card or recall), and the programme goal is more than 90 per cent; coverage is now tracked in the U-WIN electronic immunisation registry, which holds the individual child's record, generates due lists and reminders and issues a digital certificate.
The four pillars of a successful round are the microplan with an accurate head count and due list, the human resources and cold chain logistics to run the sessions, communication and social mobilisation by the ASHA, anganwadi worker and community and religious leaders, and an accountability framework of district task forces, supervision and concurrent monitoring.
The commonest field reasons a child is missed are migration, a lost Mother and Child Protection card, a previous adverse event that frightened the family, a session that clashes with the working day, and simple absence of the family on the session day; each has a different answer, which is why the ASHA's line list rather than a mass announcement is the working tool.

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