We at WHO are very pleased to see such in-depth coverage of the campaign in Karachi and the astute observations of gaps in implementation of the SNIDs. However, we are also very concerned about the weaknesses and gaps that remain, particularly in large cities of Pakistan. Similar problems were noted during the SNIDs in Lahore. It is essential that in these final stages of polio eradication in Pakistan, we all do our part to ensure that poliovirus transmission is interrupted in Pakistan before the end of the year 2001.
Health professionals counter any mis-information that can be damaging to the program.
There is no evidence that inceasing the gap from one month to two months between OPV doses or any interval increases the risk of vaccine associated paralysis. The optimal interval between campaign doses is considered to be 4-6 weeks. Increasing the interval by two more weaks is not detrimental. In the case of Karachi and many other parts of Pakistan, interval between doses had to be increased and campaigns conducted in very hot weather mainly to accomodate to the staggered supply of OPV from vaccine manufacturers due to the global shortage of OPV that was experienced in late 1999 and early 2000. Finally, we appreciate your interest and involvement with polio eradication in Pakistan.