Temperature integrity and exposure of vaccines to suboptimal temperatures in cold chain devices at different levels in three states of India.

Objective: To document the temperature integrity at the vaccine storage devices at various levels in three states of India.

Methods: A total of 213 health facilities including 196 facilities (district and sub-district levels) from 27 select districts and 17 division or state level vaccine stores in three states were included. At these facilities, temperature in 223 vaccine storage devices was recorded for at least 7 consecutive days using electronic temperature datalogger.

Results: During the observation period, overall the vaccines were exposed to temperature < 0 °C for 14.8% of the storage time with 8.6, 6.7 and 18% at state/division, district and sub-district vaccine stores, respectively. The vaccines were also exposed to temperature > 8 °C for 6.6% of the storage time including 1.3, 13 and 5.1% at state/division, district and sub-district vaccine stores, respectively. Continuous episodes of temperature deviation for 45 min or longer to < 0 °C and > 8 °C was observed in 7.2 and 6.4% of the observation period, respectively. These temperature deviations were not captured by the routine temperature monitoring practice.

Conclusion: The vaccines were exposed to freezing temperature for a considerable period at all level stores, which was more than the exposure to higher temperature. To ensure vaccine potency and immunogenicity, stringent temperature integrity maintenance is needed at all levels.