The deployment of vaccines during outbreaks has led to a significant reduction in deaths and illnesses, according to a comprehensive study conducted by Gavi, the Vaccine Alliance, and Australia’s Burnet Institute. Published in the British Medical Journal (BMJ) Global Health, the study analyzed 210 outbreaks across 49 low-income countries over a 23-year period, revealing that rapid vaccine deployment during outbreaks of diseases such as cholera, Ebola, measles, meningitis, and yellow fever resulted in an average reduction of nearly 60% in illnesses and deaths.
For diseases like yellow fever and Ebola, the impact was even more dramatic. The study found that yellow fever deaths dropped by an astounding 99%, while Ebola fatalities fell by 76%. These findings underscore the critical role of emergency vaccination and the importance of preparedness and speed in response to emerging health threats.
“For the first time, we are able to comprehensively quantify the benefit, in human and economic terms, of deploying vaccines against outbreaks of some of the deadliest infectious diseases,” said Sania Nishtar, CEO of Gavi. “This study demonstrates clearly the power of vaccines as a cost-effective countermeasure to the increasing risk the world faces from outbreaks.”
Gavi: A Lifesaving Partnership
Gavi, the Vaccine Alliance, is a unique global partnership that plays a vital role in vaccinating nearly half of the world’s children against deadly and debilitating diseases. The alliance brings together developing country and donor governments, the World Health Organization (WHO), UN Children’s Fund (UNICEF), the World Bank, the Bill & Melinda Gates Foundation, and other key partners to expand access to immunization.
In addition to its vaccination efforts, Gavi maintains global vaccine stockpiles for major diseases, managed in coordination with WHO, UNICEF, Médecins Sans Frontières (MSF), and the International Federation of Red Cross and Red Crescent Societies (IFRC).
Quantifying Lives and Costs Saved
The study also highlighted the economic benefits of emergency vaccination during the 210 outbreaks studied, generating nearly $32 billion in economic benefits from averting premature deaths and years of life lost to disability. The authors of the study suggest that this figure is likely a conservative estimate, as it does not account for the broader social and macroeconomic impacts of major outbreaks.
“The 2014 Ebola outbreak in West Africa, which occurred before an approved vaccine was available, cost the region an estimated $53 billion. In contrast, later outbreaks responded to with emergency vaccines saw deaths reduced by three-quarters and the threat of regional spread dramatically lowered.”
Disease-by-Disease Gains
The study provides a detailed breakdown of vaccine effectiveness by disease. Measles, one of the most infectious viruses known, saw cases drop by 59% and deaths by 52% thanks to outbreak response campaigns. Yellow fever saw the biggest gains, with emergency vaccination nearly eliminating deaths—a 99% drop.
Cholera and meningitis, which often strike communities with limited healthcare access and infrastructure, experienced more modest but still meaningful reductions in cases and deaths. Vaccinations helped reduce cholera cases and deaths by 28% and 36%, respectively, across 40 cholera outbreaks between 2011 and 2023. For meningitis, cases and deaths fell by 27% and 28% respectively over 10 years.
Vaccines, COVID-19, and Future Threats
The COVID-19 pandemic served as a stark reminder of the value of vaccines, which saved an estimated 20 million lives globally in the first year of rollout alone, according to the Lancet medical journal. However, the pandemic also disrupted routine immunization, leading to dangerous backsliding in coverage rates for diseases like measles and polio.
The Gavi study emphasizes that emergency vaccination must be paired with strong routine immunization systems to prevent future outbreaks. Looking ahead, Gavi’s 2026-2030 strategy includes expanding stockpiles, accelerating vaccine access for diseases like mpox and hepatitis E, and supporting preventive campaigns in high-risk regions.
This development represents a significant step forward in global health security, highlighting the need for continued investment in vaccine research, production, and deployment to protect vulnerable populations worldwide.
