Immunization is one of the most cost-effective public health interventions to date, averting an estimated 2 to 3 million deaths every year. As a direct result of immunization, the world is closer than ever to eradicating polio, with only three remaining polio endemic countries – Afghanistan, Nigeria and Pakistan. Children under 5 deaths from measles, a major child killer, declined by 85 per cent worldwide and by 89 per cent in sub-Saharan Africa between 2000 and 2016. And as of March 2018, all but 14 countries have eliminated maternal and neonatal tetanus, a disease with a fatality rate of 70 to 100 per cent among newborns. The percentage of children receiving the diphtheria, tetanus and pertussis vaccine (DTP) is often used as an indicator of how well countries are providing routine immunization services. In 2017, global coverage rates for the third dose of the diphtheria, tetanus and pertussis vaccine (DTP3) reached 85 per cent, up from 72 per cent in 2000 and 21 percent in 1980. Still, progress has stalled over the current decade, and 71 countries have yet to achieve the Global Vaccine Action Plan (GVAP) target of 90 per cent or greater coverage of DTP3. 19.9 million children under 1 year of age worldwide did not receive the three recommended doses of DTP in 2017, and 20.8 million children in the same age group had failed to receive a single dose of measles-containing vaccine.
Conflict is one of the main factors – along with under-investments in national immunization programmes, vaccine stock-outs and disease outbreaks – disrupting health systems and preventing sustainable delivery of vaccination services. About 40 per cent (almost 8 million) of the of the under-immunized infants live in fragile or humanitarian settings, including countries affected by conflicts. These children are the most vulnerable to disease outbreaks. In Yemen, for example, children accounted for over 58 per cent of the more than one million people affected by a cholera outbreak or watery diarrhoea in 2017 alone.
In 2017, 10 countries had less than 50 per cent coverage for DTP3 or the first dose of measles containing vaccine (MCV1), many of which are fragile states and affected by emergencies: Angola, Central African Republic, Chad, Equatorial Guinea, Guinea, Nigeria, Somalia, South Sudan, Syrian Arab Republic and Ukraine. But more than half of all children unvaccinated for DTP3 lived in just five countries: Nigeria, India, Pakistan, Indonesia, Ethiopia. Note that populous developing countries may contribute significantly to the number of unvaccinated children despite achieving relatively high rates of immunization coverage. Efforts to raise global immunization levels will require a strong focus on the countries where the highest numbers of unvaccinated children live – while also ensuring that countries where children are most likely to miss out on immunization are not neglected.
Through UNICEF’s joint efforts with partners and countries, vaccines have become safer and more accessible than ever before. The cost of fully immunizing children in low-income countries is just US $18 per child, down from US $24.5 in 2013. An increasing number of countries are now offering pneumococcal conjugate vaccine (134 countries as of end of 2017) and rotavirus vaccine (90 countries as of end of 2017) in their immunization programmes, thus offering protection against pneumonia and diarrhoea. Human papillomavirus (HPV) is the most common viral infection of the reproductive tract, and can cause cervical cancer in women. In 2017, the HPV vaccine was introduced in 79 countries. Use of underutilized vaccines, such as those against yellow fever and Japanese encephalitis, has also been expanded. However, while low income countries have largely been able to close coverage gaps with assistance from Gavi, the Vaccine Alliance, vaccine introduction is lagging in middle income countries who struggle to find both national resources and external funding sources.
No child should die from a preventable cause, and all children should be able to reach their full potential in health and well-being. The cost of a vaccine, often less than US $1, is much lower than the cost of treating a sick child or fighting a disease outbreak. Each US $1 invested in childhood vaccination produces a return on investment of US $44 in low and middle income countries. More details on the cost and financing of vaccination can be found here.
REFERENCES
- Levine, O.S., et al., ‘The Future of Immunisation Policy, Implementation, and Financing’, Lancet, vol. 378, 2011, pp. 439─448.
- Patel MK, Gacic-Dobo M, Strebel PM, et al., Progress Towards Regional Measles Elimination – Worldwide, 2000-2015, MMWR Morb Mortal Wkly Rep 2016; 65:1228-1233. DOI: http://dx.doi.org/10.15585/mmwr.mm6544a6
