Health officials in Pakistan “have formally complained to the WHO concerning the quality of [oral polio vaccine (OPV)] doses distributed by the U.N. body,” SciDev.Net reports, noting 58 children became infected with polio in 2012 despite having received the vaccine. Abdul Wakeel, assistant director of the government’s immunization program in the Khyber Pakhtunkhwa province, warned, “When people see children getting polio despite being given OPV — sometimes even after 15 times — they lose confidence in the ability of vaccination to protect their children,” the news service states.

“Wakeel said, however, that it was possible that batches of the ‘live’ polio vaccine may have lost potency through poor cold chain maintenance at health facilities,” SciDev.Net writes. Kamran Sultan, a WHO immunization expert, noted that low levels of education among vaccinators might contribute to the improper storage of vaccine vials, the news service notes, adding, “Shukaib Adnan, an immunization officer with UNICEF, says that besides poor cold chain maintenance and inept vaccinators there was the question of administering OPV to children whose immunity may have been compromised by illnesses” (Yusufzai, 2/20).