World Pneumonia Day: Climate change, migration, and misinformation are combining to hinder global access to a life-saving vaccine against child pneumonia

About the Authors: Anita Shet, MD, PhD, is a professor of international health and a pediatric infectious diseases specialist at the International Vaccine Access Center at the Johns Hopkins Bloomberg School of Public Health. Rose Weeks, MPH, is a senior research associate at the Johns Hopkins Bloomberg School of Public Health Department of International Health. The authors’ views are their own and not those of the Johns Hopkins University.

Pneumonia remains one of the leading infectious causes of death among children under 5. This devastating illness claims the lives of over 700,000 children each year—one every 43 seconds. Major health advances, such as antibiotics, oxygen, and fluids, have reduced the death rate, but the most efficient way to prevent bacterial pneumonia is to vaccinate against pneumococcal disease, a deadly infection caused by Streptococcus pneumoniae. Since the two decades that a safe and effective vaccine—the pneumococcal conjugate vaccine (PCV)—was licensed in the western world, progress in protecting children all over the world has been slower than expected.

Today, 46 million children under 1 year are still missing out on this life-saving vaccine—about one in three worldwide. Meanwhile, the number of children who received three doses of the vaccine against diphtheria, tetanus and pertussis (DTP), the bellwether for vaccination adequacy, was 84% in 2023, lower than in pre-pandemic years.

The first challenge remains to introduce PCV in the 34 countries where it’s not yet part of the national immunization program (see countries in pale green and gray).

However, the disappointing stagnation in the wake of the COVID-19 pandemic is more complex than it appears. In our analysis of PCV3 coverage in 14 large countries with PCV in their vaccine program, we found that while seven countries achieved a significant increase between 2019 and 2023, the remaining seven saw significant declines between 2019 and 2023 (see chart).

Four reasons for these dynamics are conflict, climate change, vaccine misinformation, and vaccine shortages.

Conflict and displacement

Conflict disrupts healthcare systems, displaces families, and strains resources, leading to lower vaccination rates among children. Of countries where PCV3 coverage decreased substantially from 2019–2023, conflict and humanitarian disasters were a major factor in three—Afghanistan, the DRC, and Nigeria. Across countries in northern Africa and Eastern Mediterranean steeped in geopolitical instability, PCV3 coverage has been slowly dropping for years.

Climate change

Climate change further exacerbates forced migration, straining health systems, as seen in Uganda. A recent study found climate disasters were hindering vaccination efforts in Africa, with vaccine storage and transportation being negatively affected. Climate change is also altering the risk of vaccine-preventable disease such as pneumonia that may be worsened by increased humidity and rainfall. 

The map, from the  Knowledge Centre of Migration and Demography, shows African net migration 1975–2015. Positive net migration is in blue; negative net migration is in red. 

Vaccine misinformation

Misinformation is a third major factor whose importance cannot be understated. In Brazil, vaccine coverage fell precipitously after 2018, concurrent with a change in country leadership. As the country chips away at vaccine hesitancy, PCV3 coverage in Brazil increased slightly in the past year.

Vaccine shortages

Paradoxically, vaccine scarcity may actually reduce people’s willingness to be vaccinated. Among 28 European countries surveyed, the majority had stockouts between 2016 and 2019. Mexico saw an 8-percentage point decline in PCV3 coverage from 2019 to 2023. In a national survey, the most common reason parents gave for not vaccinating children was a shortage of vaccines. Vaccine procurement missteps were associated with six million children missing out on vaccines, leading to speculation that people’s life expectancy was reduced by at least three years.

A deep understanding of these barriers is key to addressing the goal for expanded vaccine access and reduction in child mortality. The following four priorities, which address multiple vaccines, are needed to achieve the Immunization Agenda 2030 PCV3 coverage target of 90% by 2030.

Expand vaccine procurement in emerging markets. PCV pricing for some middle-income countries was up to 12 times higher than in other similar countries. Indigenous production is powering India’s own rapid scaleup of the vaccine, with PCV3 coverage reaching 83% in 2023, placing the country on track to attain 90% coverage by 2030.

Provide better data disaggregation. Greater detail will shed light on subnational differences within countries and enable tailored support where immunization services are not reaching children—including regions with migrant populations or climate disasters. Growing internal inequities in vaccine coverage was seen for the first doses of DTP and measles vaccine; the same is likely true for PCV coverage.

Ensure resiliency in logistics systems. Droughts, floods, and climate-driven displacement have hindered PCV introduction and sustainability, underscoring the need for governments to work with partners to build resilient and adaptive infrastructure. Aid should be available for such critical adaptations. Yet surge financing for COVID-19 has hidden a worrisome trend in reducing other support; official non-COVID development assistance for health reached a 13-year low in 2021. Global health spending from the U.S. may be threatened in the future.

Increase vaccine demand. Use tailored approaches to address information voids and misinformation, as seen in Brazil, to bring DTP and other vaccine coverage levels back up to pre-pandemic levels and ensure PCV and newer vaccines can reach all children.

The world’s most vulnerable children deserve a fighting chance. Ensuring equitable access to life-saving vaccines like PCV is not just a moral duty—it’s a global call to action. We must act now to end preventable deaths and give every child the chance to thrive.