Ramya Kannan

CHENNAI: The Central expert committee, deputed by the Union Health Ministry to Tiruvallur on Friday to inquire into the deaths of four children who received measles vaccination on Wednesday, has cleared the district’s cold chain system used to store the vaccines, The Hindu has learnt reliably.

Post-mortem reports have confirmed that the children died of anaphylactic shock.

This indicates that a foreign protein (e.g. bacteria) had found its way into the vaccine.

State health officials said the team had given a clean chit to the cold chain equipment used to store and transport the vaccines and found the temperature had been “perfectly” maintained as per WHO specifications.

Only the laboratory analysis at Kasauli could now confirm the cause of contamination.

In the storage centres, the vaccines were kept in the special ice-lined refrigerator in temperatures between 2 and 8 degrees Celsius.

The team checked the temperature recording and the registers in the two PHCs – Katchur and Koonimangadu - and found them satisfactory.

The team also examined the vaccine vial monitors on vials used to inoculate the children who died for any indication that temperature disruptions affected the vaccine quality. None of them showed any change.