Supply and delivery of vaccines for global health

Abstract

Vaccines developed in high-income countries have been enormously successful in reducing the global burden of infectious diseases, saving perhaps 2.5 million lives per year, but even for successful cases, like the rotavirus vaccine, global implementation may take a decade or more. For unincentivized vaccines, the delays are even more profound, as both the supply of a vaccine from developing country manufacturers and vaccine demand from countries with the high disease burdens have to be generated in order for impact to be manifest. A number of poverty-associated infectious diseases, whose burden is greatest in low-income and middle-income countries, would benefit from appropriate levels of support for vaccine development such as Group A Streptococcus, invasive non-typhoid salmonella, schistosomiasis, shigella, to name a few. With COVID-19 vaccines we will hopefully be able to provide novel vaccine technology to all countries through a unique collaborative effort, the COVAX facility, led by the World Health Organization (WHO), Gavi, and the Coalition for Epidemic Preparedness Innovations (CEPI). Whether this effort can deliver vaccine to all its participating countries remains to be seen, but this ambitious effort to develop, manufacture, distribute, and vaccinate 60-80% of the world's population will hopefully be a lasting legacy of COVID-19.

Figure 1

Timeline and milestones of the supply chain for five vaccine preventable diseases (VPD). Courtesy of International Vaccine Access Center.

Figure 2

Vaccine timelines and uptake from first Gavi-supported introduction for four Vaccine Preventable Diseases (Penta: pentavalent (diphtheria, tetanus, whooping cough, hepatitis B and Haemophilus influenzae type B) vaccine; RVV: rotavirus vaccine; PCV: pneumococcal conjugate vaccine; IPV: inactivate poliomyelitis virus vaccine). Courtesy of International Vaccine Access Center. Source: World Health Organization. WHO/UNICEF Estimates of National Immunization Coverage for 1980-2016, 2017. https://apps.who.int/immunization_monitoring/globalsummary/timeseries/tswucoveragedtp3.html.