THERE has been widespread anxiety about the implications of the recently enforced polio-related travel advisory issued by the World Health Organisation (WHO) for Pakistani travellers. While experts understand the scientific rationale for many of the steps taken, these have not been clearly communicated to the public, a gap this article hopes to address.

The current polio situation in Pakistan is worrisome. From Jan 1, 2014 to July 15, 2014, there have been 123 confirmed cases of polio worldwide, and 94 of them have occurred in Pakistan. During the same period last year, there were 132 cases worldwide and only 21 of those were in Pakistan. Pakistan is the only country in the world where polio cases have increased so dramatically in 2014.

There are two main reasons for continued polio incidence in Pakistan. Firstly, a large proportion of our population, especially children, is malnourished. Many do not develop immunity to polio despite multiple doses of vaccine like a healthy child would. Even in healthy children, one dose of oral polio vaccine induces immunity in only 50pc of the children. Hence our children need more doses as compared to children in developed countries.

Secondly, we have a segment of population that is ‘persistently missed’ in the polio vaccination campaigns. If we see the distribution of polio cases across Pakistan in 2014, 74pc of them have been in Fata, 17pc in KP and 9pc in Sindh. Vaccination campaigns have not been possible in Fata over the past two years and this population is unfortunately the biggest driver of polio across the country. The current military operation and the resulting movement of local residents to settled areas provide an opportunity to vaccinate children from this inaccessible region.

The travel restrictions are not a ‘punishment’ for Pakistanis.

It is important to realise that the travel restrictions are not a ‘punishment’ for Pakistanis for their failure to eradicate polio. In 1988, WHO decided to eradicate polio from the world, as had been done in the case of smallpox. While most countries have era­dicated polio, even if a single person infected with polio virus exists anywhere in the world, the potential for the disease to make a comeback remains. Indeed, many cases of polio have been detected in ‘polio-free countries’ from virus ‘imported’ from polio-endemic countries which include Pakistan, Nigeria and Afghanistan. These travel recommendations are intended to prevent the export of polio virus from such countries to those which are currently polio-free.

All travellers going out of Pakistan are now supposed to be vaccinated against polio before travel and obtain a certificate that shows they have received the vaccine. Ideally, this certificate should be obtained four weeks before travel, but if that is not possible, any time before travelling will be acceptable. Certificates will be valid for one year.

There is also considerable anxiety in the public as to the quality and safety of polio vaccines, especially if multiple doses are given in door-to-door campaigns. Two types of polio vaccines are available: oral polio vaccine (OPV), which is given by mouth, and injectable polio vaccine (IPV). Both are very safe. There is an extremely small risk of developing vaccine-associated paralysis (one in 2.7 million doses) with oral vaccine, which is much smaller compared to the risk of becoming infected with polio if you are not vaccinated.

This risk is incurred when getting the OPV vaccine for the first time. With the second, third and subsequent doses, the risks are even smaller. If someone is pregnant or has a weakened immune system, they should talk to their doctors and get the IPV instead of the OPV. For others, OPV is preferred.

Regarding quality, all OPV vaccines used in Pakistan are pre-qualified by WHO and procured by Unicef. They have a special viability marker on every vaccine vial, which clearly becomes discoloured if the vaccine is exposed to excessive heat or cold. If the vaccine marker is not discoloured, one can rest assured that the vaccine is potent and safe. IPV is very safe, perhaps one of the safest vaccines ever made.

Polio is a devastating disease which causes permanent disability and death in children. We are focused on polio because just like smallpox, polio can be completely eradicated. The possibility that our future generations will not have to worry about this crippling disease, and the fact that we are not far from achieving this goal makes us all the more eager to make this final push to achieve polio eradication.

Let us all play our part in eradicating polio from Pakistan and the world by following these travel recommendations and by making sure every child under five years old in Pakistan gets the vaccine in every polio vaccination campaign. Multiple doses are not only safe, they are critically important in protecting our children from polio.

The writer is general secretary of the Medical Microbiology and Infectious Disease Society of Pakistan and assistant professor, paediatric infectious diseases, Aga Khan University.

Published in Dawn, July 24th, 2014