India’s immunization program is one of the largest Universal Immunization Programs (UIP) in the world. In India, the Universal Immunization Program targets 27 million infants and 30 million pregnant women every year. Effective vaccine utilization is an integral component of vaccine security and vaccine wastage is one of the key factors to be considered with regards to vaccine forecasting and need estimation. Heat sensitivity of most vaccines calls for the need of adequate cold-chain system and ensure its maintenance to preserve the potency of the vaccine before it is administered. The World Health Organization (WHO) recommends that all childhood vaccines except the oral polio vaccine be kept at 2–8 °C during their in-country distribution.
In a bid to ensure success of the immunization program, India has a five-level supply chain. It commences at the government medical supply depots (n=4) which supply state vaccine stores (n = 35), which, in turn, supply regional vaccine stores (n = 116). Vaccine is sent from the regional stores to district vaccine stores (n = 626), and thereon the last links in the chain: the primary or community health centers function as the peripheral vaccine stores (n = 26 439).
In spite of all the positive efforts there are ongoing challenges and shortcoming in the program that hamper the coverage rates.Within the entire chain, storage of vaccines at optimum temperature is critical. Most vaccines(except the oral polio vaccine) need to be stored at temperature between 2–8 °C.This is either achieved by building walk-in coolers or ice-lined refrigerators or transported in cold boxes with ice packs that have been allowed to reach 0 °C.Immunization services in the public sector are mostly provided at district hospitals, urban health centers and primary or community health centers. However, outreach vaccination sessions at health subcenters or in remote villages are also conducted, using vaccine transported from the nearest primary or community health center.
A study by Galhotraet al in the year 2007 highlighted incidence of avoidable errors like uninterrupted power supply, in adequate number of exhaust fan, voltage stabilizers, etc. were the identified reasons for the errors and cited a room for improvement.
Use of thermo stable vaccines is on the anvil and is likely to change the dynamics in future.