- Global vaccine stockpiles helped prevent over 5.8 million cases and 327,000 deaths since 2000
- Gavi funds vaccine roll-outs and outbreak response immunisation in low- and middle-income countries
- Study analysed 210 outbreaks of five diseases across 49 countries from 2000 to 2023
Global stockpiles of vaccines under programmes supported by 'Gavi, the Vaccine Alliance,' helped prevent more than 5.8 million cases and 327,000 deaths from outbreaks in low- and middle-income countries since 2000, according to a new study.
The alliance, established in 2000, funds the roll-out and scale-up of new vaccines through routine healthcare systems and preventive campaigns.
The findings, published in the British Medical Journal (BMJ) Global Health, highlight life-saving impacts and economic benefits of nearly USD 32 billion due to outbreak response immunisation programmes aimed at containing vaccine-preventable disease outbreaks.
"For diseases with routine vaccination programs, maintaining high levels of population immunity is vital for preventing large outbreaks," lead author Dominic Delport, a PhD candidate at Burnet Institute, an Australian-based medical research institute and NGO said.
"But when outbreaks do occur, a rapid vaccine response typically provides the greatest protective impact for the population at risk -- and the faster the response, the greater the impact," Delport said.
The researchers added that with routine vaccination declining and also impacted by cuts to the US' foreign aid, the study highlights the ongoing need for an insurance policy against major outbreaks of diseases like cholera, Ebola and measles.
The study analysed 210 outbreaks across 49 low- and middle-income countries that occurred between 2000-2023 for five diseases -- cholera, Ebola, measles, meningitis and yellow fever.
Globally, routine vaccine coverage has been shown to falter, with a recent study published in The Lancet journal attributing this to persistent inequalities, challenges due to the COVID-19 pandemic, and a growth of vaccine misinformation and hesitancy -- factors which increase the risk of vaccine-preventable outbreaks, it said.
Low- and middle-income countries have been studied to bear the major brunt of these outbreaks.
Senior author Nick Scott, associate professor and head of modelling and biostatistics, Burnet Institute, said the global decline in routine vaccine coverage highlights the value of vaccine stockpiles as insurance against major outbreaks.
"Routine vaccine coverage is declining due to many factors including vaccine hesitancy and funding cuts for organisations like USAID and Gavi, and in many places gaps in coverage due to COVID-19 disruptions haven't been filled yet," Scott said.
"And as routine coverage declines, the prospect of more major outbreaks means there's a growing need for global vaccine stockpiles," the senior author said.
The authors wrote, "Across 210 outbreaks, ORI (outbreak response immunisation) programmes are estimated to have averted 5.81 million cases 327,000 deaths." The team also looked at the impact of outbreak response immunisation programmes in helping control large outbreaks in low- and middle before they became overly disruptive.
Larger outbreaks are linked with worse health and economic outcomes, often requiring more disruptive public health measures that involve travel interruptions and school and business closures.
"We found here that the presence of the (outbreak response immunisation) consistently resulted in smaller outbreaks (eg, reducing the percentage of measles outbreaks with more than 100,000 cases from 41 per cent to eight per cent)," the authors wrote.
"(Outbreak response immunisation) programmes are critical for reducing the health and economic impacts of outbreaks of vaccine-preventable diseases," they wrote.
