KARACHI, Nov 18: More than 85 per cent of the children in Sindh, who were diagnosed as having polio this year, were administered anti-polio drops several times , sparking off fears that the country may not be free of the debilitating disease in the near future.

The news of the dangerous trend comes at a time when the health authorities are resigned to the fact that they will not be able to meet the target of bringing polio cases to zero by the end of the year. They, however, seem satisfied that the number of polio cases are on the decline.

The health secretary, Prof Noshad Sheikh, and provincial project director of the Expanded Programme for Immunization (EPI), Dr Ali Nawaz Sheikh, both confirmed on Thursday that several cases had been detected in which children, who had been vaccinated against polio, had been infected with the disease. They said the children who had been administered anti-polio drops less than ten times remained vulnerable to the disease.

According to Dr Laila Rizvi of the Unicef, until last week a total of 36 cases of polio had been detected in the country. "The number of cases for Sindh stood at 20," she said.

When asked how many of these children had been vaccinated against polio, she said: "The data for all the 20 children are not available right now. However, of the 16 cases about which we have complete data, 14 had been immunized."

Elaborating, Dr Rizvi said six of the children had been administered OPV doses two to five times. "Six of the children had been vaccinated between five and 10 times and two of them had been given anti-polio drops more than ten times."

Answering a question, she said the efficacy of the vaccine was not an issue. "Neither is the maintenance of the cold chain, which is easy to monitor."

Dr Rizvi was of the opinion that personal hygiene and sanitation could be major factors in what was transpiring. "But I cannot be certain because a proper study is required to decipher the reasons."

Dr Asif Aslam of Unicef and Dr G.N. Kazi of the World Health Organization too acknowledged that several cases had surfaced in which children immunized several times had fallen prey to the disease.

Dr Kazi pointed out that the effectiveness of the anti-polio drops could never be expected to top 80 per cent. "So, there's always a possibility that polio may strike even if a child is vaccinated."

He said the WHO recommended that every child must be administered the vaccine at least four times under the routine immunization programme. "In addition, he or she must be vaccinated during every National Immunization Day (NID)."

When Dr Ali Nawaz Sheikh, the chief of EPI Sindh, was contacted he said a child must be vaccinated more than 10 times against the crippling disease. "We put this question of infection among the vaccinated children to six well-known paediatricians, including Prof Gaffar Billo, Prof D.S. Akram and Prof Iqbal Memon.

"And all of these professors recommended that each child should be vaccinated against polio more than 10 times." He said the authorities were satisfied so far as the efficacy of the vaccine was concerned.

"Look, the vaccine that we are using is the same one which was used in all the countries from where polio has been banished. This only shows that the vaccine is fine."

Prof Noshad Sheikh, the health secretary, said the children afflicted with polio despite being immunized against it were not as sick as those who were not. "The already-immunized children are better off as their handicap is less severe when compared to those who were not administered any drops."

Meanwhile, the chief of the EPI Sindh told Dawn that a total of eight NIDs had been planned for 2005. This was confirmed by the health secretary. It is, therefore, business as usual for the health department when it comes to polio.