Via The Lancet, an excellent overview: Polio eradication effort sees progress, but problems remain. Excerpt:
By contrast, polio in Pakistan has become a nightmare for Pakistani health officials and for the global eradication programme. Over the past 12 months, 112 cases were reported there versus 49 in the previous 12 months.
The increase is not surprising, given the context: more than 40 vaccination staff have been killed since July, 2012, allegedly by Taliban fighters. In the North Waziristan Agency of the Federally Administered Tribal Areas local leaders have banned immunisation campaigns since June, 2012.
“No immunisation means no eradication”, Aylward says. “And already there is evidence of cross-border spread of the virus from Pakistan into Afghanistan. Last year, a Pakistan strain of poliovirus was detected in sewage samples from Egypt, Israel, the West Bank and the Gaza Strip, and exploded into an outbreak in Syria in late 2013.”
The Independent Monitoring Board that keeps WHO Director-General Margaret Chan abreast of progress, or lack of it, in eradicating polio, pulled no punches in its Feb 26 report:
“The current situation in Pakistan is a powder keg that could ignite widespread polio transmission…The new government has been slow to grasp the fundamental seriousness of the situation. If the current trend continues, Pakistan will be the last place on earth in which polio exists.”
How to surmount the Pakistan hurdle? Aylward explains: “First, the murder of health workers has to stop and those responsible must be held accountable. Who pulled the trigger or said that the trigger should be pulled? Then, vaccination has to resume in Waziristan. And that means working out with the Waziri leaders how to get their children vaccinated. Then the full assistance of the Pakistan military is needed to make sure that vaccination can be done safely, especially in the many, large conflict areas.”
The programme's worries, however, go beyond the three endemic countries. Last year was marked by a rash of outbreaks in five countries that had been free of polio—Cameroon, Kenya, Ethiopia, Somalia, and Syria.
Of the 240 cases in these reinfected countries, 199 occurred in the Horn of Africa (Somalia, Kenya, and Ethiopia) and were caused by a virus imported from Nigeria. As The Lancet went to press, the outbreaks are continuing, but slowing down, thanks to the firewalling of infected areas with massive vaccination campaigns over a period of 18 weeks (seven rounds in Somalia and more than 3 million children vaccinated in Syria, despite the difficulty of reaching children in the conflict-ravaged areas of the country).
The race is on
Not all, though, is gloom-and-doom. Of the three poliovirus strains, the type 2 strain, last seen in 1999, has been eradicated. The third (type 3) strain, last seen in Nigeria in November, 2012, may also have been eradicated. If only type 1 remains, global eradication could be more easily achieved.
A further boost to GPEI morale comes from the announcement, on Feb 28, of an agreement by vaccine manufacturers to supply the injectable polio vaccine (IPV) for less than US$1 per dose for the 73 low-income countries eligible for support by the GAVI Alliance, a public-private partnership.
The oral polio vaccine (OPV), which has been the vaccine of choice since the start of the programme and has proved highly effective, carries attenuated live poliovirus that occasionally becomes active and spreads the infection. The IPV uses totally inactivated virus that cannot spread and will therefore be a safer tool for the post-eradication strategy.
“The race is now on to get all countries using the IPV in order to accelerate the eradication process and—eventually, after eradication—to stop using OPV”, says Aylward.