Inactivated polio vaccine launch in Nepal: a public health milestone
Authors: Andreas Hasman, Hendrikus C J Raaijmakers, Douglas J Noble
Journal: The Lancet Global Health (2014)

On Sept 18, 2014, as part of the Global Polio Eradication Initiative (GPEI), Nepal became the first GAVI-supported country in the world to introduce one dose of inactivated poliomyelitis vaccine (IPV) into routine immunisation schedules at 14 weeks. The launch at Tribhuvan University Teaching Hospital, Kathmandu, is a significant step, but there are challenges ahead. Introduced in 1955, IPV was the first vaccine against polio—its discovery was a great advance in public health.1David M OshinskyPolio: an American story. Oxford University Press, New York2005Google Scholar Yet, it was eventually the oral polio vaccine (OPV) that became the world's preferred vaccine because of lower cost, ease and safety of production, a simple route of oral delivery, and its efficacy in stopping virus circulation.2Paul A OffitThe Cutter incident: how America's first polio vaccine led to the growing vaccine crisis. Yale University Press, New Haven and London2007Google Scholar, 3Global Polio Eradication InitiativeOral polio vaccine (OPV).http://www.polioeradication.org/Polioandprevention/Thevaccines/Oralpoliovaccine(OPV).aspxGoogle Scholar OPV was included in routine immunisation programmes, and the GPEI still uses OPV extensively in supplementary immunisation activities in efforts to eradicate polio. Since 1988, the global incidence of polio has fallen by more than 99%.4Global Polio Eradication InitiativePolio eradication and endgame strategic plan 2013–2018.http://www.polioeradication.org/resourcelibrary/strategyandwork.aspxGoogle Scholar However, in rare cases, OPV can cause vaccine-associated paralytic poliomyelitis (2–4 cases per million birth cohort per year) and circulation of vaccine-derived poliovirus.5WHOPolio vaccines: WHO position paper.Wkly Epidemiol Rec. 2014; 89: 73-92PubMed Google Scholar OPV contains certain live attenuated strains of the virus that can sometimes mutate and revert to virulent vaccine-derived poliovirus (mostly type 2 poliovirus), as opposed to IPV which contains fully inactivated or killed strains. As long as live attenuated strains are used in polio vaccines, final eradication cannot occur. IPV therefore mitigates risks posed by OPV. New evidence from India also suggests that when IPV is given to OPV-vaccinated individuals, better immunity is achieved.6JJafari H Deshpande JM Sutter RW et al.Efficacy of inactivated poliovirus vaccine in India.Science. 2014; 345: 922-925Crossref PubMed Scopus (88) Google Scholar It is no coincidence that Nepal is the first of 72 planned GAVI-funded countries to introduce IPV. After stopping polio transmission in 2000 and responding effectively to subsequent importations from India, the last case was in 2010.7Kew O Reaching the last one per cent: progress and challenges in global polio eradication.Curr Opin Virol. 2012; 2: 188-198Crossref PubMed Scopus (44) Google Scholar, 8WHOWHO vaccine-preventable diseases monitoring system: 2014 global summary.http://apps.who.int/immunization_monitoring/globalsummary/countries?countrycriteria%5Bcountry%5D%5B%5D=NPLGoogle Scholar Nepal also has a high-performing immunisation programme, with coverage rising from 43% in 1990 to 90% in 2012.9UNICEF South AsiaImproving children's lives, transforming the future: 25 years of child rights in South Asia.http://generation25.org/wp-content/uploads/2014/09/Improving-Children-s-Lives-Transforming-the-Future.pdfGoogle Scholar The immunisation programme has strong political commitment, and effective partnerships between government, civil society, and international organisations including WHO, UNICEF, Rotary International, GAVI, and USAID. Professional associations have had a pivotal role: the Nepal Paediatric Society and the Society of Public Health Physicians Nepal were advocates for the introduction of IPV. But there are challenges ahead with IPV introduction, and carefully crafted and field-tested communication efforts are needed to explain the issues to the public and professionals alike. First, the introduction of the new vaccine is to be used alongside an existing vaccine for the same disease. One dose of IPV is to be introduced in parallel with OPV to particularly bolster immunity to type 2 poliovirus (type 2 causes most of the current vaccine-related problems). Subsequently there will be a switch in the kind of OPV from that containing type 1, 2, and 3 poliovirus (trivalent OPV) to one without type 2 (bivalent OPV). Once virus circulation has been stopped everywhere, OPV can be withdrawn. The science is complex and a challenge to explain to the medical profession and caregivers. In Nepal, media outlets gave an early sense of how the lay public could respond to IPV. One noted that IPV was “the latest antidote to polio” and reported an expert as saying that it “[boosted] immune system big time”.10AnonNepal becomes first in SE Asia to administer IPV.Republica. Sept 18, 2014; (accessed Sept 22, 2014).http://www.myrepublica.com/portal/index.php?action=news_details&news_id=83400Google Scholar Another source ran with the headline: “Polio vaccination to be intravenous”,11AnonPolio vaccination to be intravenous.EKantipur. Sept 16, 2014; (accessed Sept 22, 2014).http://www.ekantipur.com/2014/09/16/capital/polio-vaccination-to-be-intravenous/395118.htmlGoogle Scholar perhaps confusing the inactivated strains in IPV given intramuscularly. Second, in most countries, new vaccines mean either more injections in a given immunisation session, or more sessions. Multiple injections at the same time pose logistical and communication challenges, and have opportunity costs. Health professionals might worry about parental concerns and caregivers might in some circumstances object to more injections for a distressed child.12Wallace AS Mantel C Mayers G Mansoor O Gindler JS Hyde TB Experiences with provider and parental attitudes and practices regarding the administration of multiple injections during infant vaccination visits: lessons for vaccine introduction.Vaccine. 2014; 32: 5301-5310Crossref PubMed Scopus (52) Google Scholar Alternatively, increasing the number of visits could lead to increased dropout rates. IPV is best given at 14 weeks. But to avoid three injections at 14 weeks (IPV, pneumococcal conjugate vaccine, and pentavalent vaccine [diphtheria, tetanus, pertussis, hepatitis B, and Haemophilus influenzae type b]), Nepal has decided to give the second dose of pneumococcal conjugate vaccine at 10 weeks, despite it being potentially less effective than at 14 weeks. Third, currently in south Asia about 8 million children have not had a third dose of diphtheria, tetanus, and pertussis vaccine in their first year of life9UNICEF South AsiaImproving children's lives, transforming the future: 25 years of child rights in South Asia.http://generation25.org/wp-content/uploads/2014/09/Improving-Children-s-Lives-Transforming-the-Future.pdfGoogle Scholar—these are often the most deprived and hardest to reach groups. In Nepal, reaching children in remote mountainous areas poses particular challenges. Addition of new vaccines, without improving and expanding the supply chain, risks stretching public health systems to the limit. Finally, in Nepal the success of polio eradication has resulted in public support for immunisation; communities play their part to ensure every child is vaccinated. For governments like Nepal's, IPV introduction might be mainly about the start of final polio eradication by working towards removing live attenuated polio vaccines. But the public might already regard polio as eradicated and not understand the need for IPV. The Maldives is planing to be the next country in south Asia to introduce IPV. After that, the rest of the region is due to follow, including Bangladesh, Pakistan, Afghanistan, and India. All have significant public health challenges. It is crucial that countries share lessons learned as IPV is rolled out, including how to address its challenges. The opinions expressed in this paper are solely those of the authors and do not necessarily represent the official position of UNICEF. We declare no competing interests.