Like many on this forum will know, Nigeria has come to be closely associated with the near collapse of the Global Polio Eradication programme. Several states in Northern Nigeria suspended polio immunization efforts for nearly a year in 2003-04 in response to vaccine safety rumours (vaccines allegedly causing impotence)
that led parents to refuse to have their children immunized. This led to the re-infection of several countries that had not had a polio virus identified for years. Nigeria was the eye of a major storm and on the lips of every public health professional. Slowly, with a lot of hard work, the situation is being turned around. With only 201 cases reported this year, there finally seems to be light at the end of the tunnel. After all the hard work in bringing the programme back on track in Nigeria, last week the news broke that the biggest outbreak of vaccine-derived polio virus (known in the shorthand of polio as VDPVs) in the literature has been going on in Nigeria with 69 cases of children paralyzed by polio related to the virus in the vaccine.
Such vaccine-linked outbreaks have occurred before but each comprised fewer than a handful of cases. The Nigerian outbreak is the largest on record involving vaccine-derived viruses. This can again be a potential threat to the polio eradication effort because of its location and the context.
The major issue at stake is why the outbreak has taken so long to come to light. There have been rumours for months, through contacts and back channels. Why would an outbreak be going on for more than a year and a half and we have nothing at all about it until now? Dr. D.A. Henderson, the infectious diseases expert who led the successful smallpox eradication program, broke the news to the public health community in the UK, in the annual Pump-Handle lecture at the LSHTM on Tuesday 11th September the before the WHO published this on the 28th of September in its Weekly Epidemic Report.
Expert opinion is divided over the danger posed by VDPVs. The WHO insists the transmission chains formed by these viruses are easier to break than those created by wild polio viruses. Others believe these viruses, if left unchecked, will become every bit as dangerous as wild polio viruses.
The consensus in the public health community is that the outbreak is as a result of under-vaccination - not vaccination itself - that caused the problem.
BUT...just how does one communicate this?
The bottom line is....whatever skepticism we might have about how the initial outbreak was handled, whatever our disappointment might be in the present communications strategy, our views (of which there are always plenty :))....WE CANNOT AFFORD TO DROP THE BALL, NOT NOW, AND NOT IN NIGERIA.
On rare occasions oral polio vaccine paralyzes children. About one out of every one million doses leads to paralysis. And the vaccinated children shed viruses in their stools for weeks. Those viruses mutate. If they circulate long enough, the built-up mutations can restore the virulence stripped out in the vaccine production process, giving these viruses back the power to paralyze months and even years after their progenitors came out of a vaccine vial.