WHO suggests probe on vaccine circulation

World Health Organisation in a study has suggested that the TS government carry out investigations to find if trivalent oral poliovirus vaccine is still in use after it was prohibited. The Centres for Disease Control and global immunisation experts were involved in the study.

The study forms part of the Weekly Epidemiological Report for January and was titled ‘Detection of sabinlike Type 2 poliovirus from sewage after global cessation of trivalent oral poliovirus vaccine — Hyderabad and Ahmedabad.’

It has asked the government to search all known vaccine cold chain storage points and conduct a physical check of public and private health facilities.

The study said that the two main district vaccine cold storages in Hyderabad and Ranga Reddy districts, along with 13 private vaccine retailers and distributors and 4,498 public and private health facilities, were searched from September 4 to October 5.

“Thirty-seven tOPV vials from four manufacturers were found in 17 private clinics; the majority were small clinics not affiliated with an organised medical association. Twenty-two of the tOPV vials were unopened; however, 15 had been partially used. Six vials were beyond their expiration date. No tOPV vials or bulk type 2 polio vaccine were found at the only vaccine manufacturer in Hyderabad,” it said.

The WHO and CDC said: “Investigation underscores the importance of maintaining robust surveillance for polioviruses and of immunisation workers being alert for tOPV vials in cold chain storage and reporting any tOPV vials that they find.”