Polio redux
The announcement of polio’s reemergence in the Philippines could not have come at a worse time, with the country still reeling from the recent measles and dengue epidemics. While the appearance of circulating vaccine-derived polioviruses (cVDPVs) is not unprecedented in the region (there have been recent similar episodes in Papua New Guinea and Myanmar), this new development is nonetheless a significant national and global setback.
As expected, many are blaming Persida Acosta, whose unfounded, hysterical claims about the dengue vaccine have undoubtedly caused mistrust in vaccines in particular, and our public health programs in general. However, although she deserves to be held accountable for her actions, making a scapegoat out of her and other “medical populists” oversimplifies a complex issue and detracts attention from long-standing public health failures.
In fact, polio immunization rates have never reached the 95 percent required for herd immunity, even as it got even lower in 2018, in part because of the Dengvaxia scandal, to 66 percent. Supply-side issues have included vaccine shortages, failures in cold chain management and lack of human resources. Meanwhile, on the demand side, geographic, financial and cultural barriers, as well as pre-existing mistrust, have served as long-standing impediments.
This low rate is particularly detrimental for polio — a disease that in severe cases can affect the nervous system, leading to paralysis and death. The very idea of vaccination is to expose people to a weakened or inactivated form of a disease; in the case of the oral polio vaccine (OPV), weakened polio strains normally give full immunity to vaccine recipients, but the strains can mutate into cVDPVs and infect unvaccinated individuals, particularly in under-immunized populations. Thus, the success of polio vaccination rests on very high coverage.
To mitigate this risk, global policymakers have tried to move from OPV to an inactivated, injectable form (IPV). They have also sought to decrease the circulating polio strains by moving from the regular trivalent OPV to a bivalent (type 1 and 3) form beginning in 2016—a move premised on the complete eradication of type 2. As both cases in the Philippines are type 2, however, the Department of Health (DOH) will have to offer monovalent OPV or IPV—and ensure supplies for both.
Given the situation, the challenge is to reform the Expanded Program on Immunization (EPI) by sorting out the supply- and demand-side issues mentioned above. Beyond EPI, moreover, broader systemic failures that impact on immunization need to be dealt with. Consider, for instance, how many nurses and midwives could not work for months because of the long delay in approving the 2019 budget.
Crucially, the DOH plans need to be urgently communicated to health practitioners and local government units. Right now, many doctors need guidance as to how to respond to worried patients, many of whom are demanding to be vaccinated. Working more closely with medical professionals and local health units can also enhance the badly needed monitoring and surveillance of polio and other vaccine-preventable diseases.
Moreover, there is a need for the government to deal with fear and lingering mistrust by being very informative and transparent about the situation (this, at least, seems to be happening)—and holding public officials accountable for misinformation, corruption and inaction. We cannot afford another Persida Acosta, but neither can we afford more issues regarding the procurement, regulation and distribution of vaccines.
Finally, there is a need to address polio’s social determinants. To be sure, vaccines remain central in eradicating polio, but the fact that the transmission of the disease is through the fecal-oral route and is facilitated by malnutrition speaks of the social and socioeconomic environmental conditions that cannot be ignored or wished away. At the very least, rural and urban poor communities deserve access to clean water, sanitation and primary health facilities.
Ultimately, all the above will require political leadership that recognizes health as a top national priority. Amid talks of the health budget being cut — even as the President gets billions in intelligence funds — will the return of a fatal, once-eradicated disease not wake up our leaders from their stupor?
