The word "cold chain" is the process used for?

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E6 Parks TextBook of Preventive & Social Medicine part 1 — Subpart A (pp 26-201 of 604) p. 103-105
E6 Text Book Of Pediatric Nursing 3rd Panchali Pal — Part 1 (pp 36-238 of 713) p. 44-46
Practise the full SCTIMST Staff Nurse - 2015 (Set-B)
Attempt every question from this paper in a timed mock, then review the full solution for each one.