Vaccine programmes in low- and middle-income countries have prevented 37 million deaths in the last 20 years alone – 36 million in children under 5.
These are the findings of the most comprehensive study of the impact of vaccination programmes yet undertaken, published today in The Lancet.
The research, led by an international consortium including researchers at Imperial College London, shows the success is predicted to continue, with a further 32 million deaths predicted to be prevented by vaccination programmes by 2030 (28 million deaths prevented in under-5s), if progress is sustained.
Professor Neil Ferguson said: “These findings show that since 2000, 36 million children under 5 have been saved by vaccines and another 28 million will be saved by 2030.
"The magnitude of this cannot be underestimated. As a result of a simple vaccination, 36 million families were not left grieving for their child or baby – and these children were given the chance to grow up.”
Infectious diseases are still a major cause of disease and deaths, especially in low- and middle-income countries. Vaccination is one of the most cost-effective health interventions available.
Childhood vaccination programmes have increased over the last two decades globally, substantially reducing disease and deaths from diseases such as measles, meningitis and hepatitis. This study offers the most reliable estimates of the impact of childhood vaccinations on mortality yet undertaken.
"As a result of a simple vaccination, 36 million families were not left grieving for their child or baby – and these children were given the chance to grow up." Professor Neil Ferguson Imperial College London
The Vaccine Impact Modelling Consortium – a multinational collaboration of 16 research groups – generated estimates from at least two independent models, for each of ten diseases.
These estimates focused on deaths averted by vaccination against 10 diseases in 98 low-and middle-income countries, in the period 2000-2030.
These countries include over two-thirds of the world’s population.
The 10 diseases in question were hepatitis B, Haemophilus influenzae type b (Hib), human papillomavirus (HPV), Japanese encephalitis, measles, meningitis A (Neisseria meningitidis serogroup A), pneumococcal disease (Streptococcus pneumoniae), rotavirus, rubella, and yellow fever.
The Consortium estimates that vaccinations against the 10 diseases considered have prevented 37 million deaths between 2000 and 2019, of which 36 million were deaths averted in children under the age of 5 years.
The study estimated a further 32 million deaths will be prevented by 2030 due to vaccine programmes, of which 28 million are deaths averted in under-5s.
During the lifetime of those born in 2019, we estimate vaccination will prevent 72% of the mortality from these 10 diseases. This proportion rises to 76% when we consider only under-5 mortality from these diseases.
Measles vaccination has had the largest estimated overall impact, with 33 million estimated deaths prevented in the period 2000-2019, equating to over 1.6 million deaths averted per year. Researchers anticipate this will increase to over 2.1 million deaths averted per year in future years (2020-2030).
The largest potential additional gains (above those already achieved) will be seen by increasing HPV vaccination coverage in girls.
This is predicted to avert more deaths per person vaccinated than any other immunisation activity. Increasing pneumococcal conjugate vaccine coverage will give the largest reductions in under-5 mortality.
These huge impacts are a testament to both the public health benefit of vaccines overall, and the sustained investment in increasing global vaccination coverage in the last two decades.
The study highlights what could be achieved by further investment in vaccination programmes by countries and donors.
Priorities for future investments include increasing coverage of vaccines against HPV and pneumococcal disease. Sustaining these health gains requires continued funding, investment, political commitment, and strengthened health systems.
Dr. Katy Gaythorpe said: “A child born in 2019 will experience a massive reduction in their risk of dying from these 10 pathogens over their lifetime, with their mortality falling by 72% due to vaccination alone.”
Dr. Xiang Li said: “In a time when the world desperately awaits a COVID-19 vaccine to help return our lives to normal, this study demonstrates how vaccines have transformed the health of the world, and given 36 million children another chance at life.”
Dr Seth Berkley, CEO of Gavi, the Vaccine Alliance, said: “This impressive study provides yet more evidence that vaccines work, and is testament to the hard work of Gavi and our Alliance partners in improving vaccine coverage across the world over the past two decades.
“As COVID-19 continues to overwhelm health systems worldwide, it is also a timely reminder that we cannot allow the pandemic to disrupt routine vaccinations. That’s why the Alliance is working day and night to help the world’s poorest countries maintain and restore their immunisation programmes, to ensure millions more children can be protected against some of the world’s deadliest diseases.”
Dr Robin Nandy, UNICEF’s Chief of Immunizations, said:
“These new data, showing that vaccinations have helped save approximately 36 million children over two decades, illustrates the remarkable impact vaccines have made in saving children’s lives across the world, especially in the poorest communities where children are particularly vulnerable.
“We can save an estimated 28 million more children in the coming years, which is why we must invest in vaccination programmes to reach those that need them most, despite recent disruptions to immunization delivery due to the COVID-19 pandemic.”
Accompanying the Lancet publication, the team developed a data visualisation tool. This tool shows the Vaccine Impact Modelling Consortium's estimates of health impact from vaccination against 10 pathogens in 98 low and middle income countries from 2000 to 2019.
This Lancet publication has also been re-written in age-appropriate language and transformed into a Science Journal for Teens paper. The package includes educator resources, assessment questions, a teachers key, opening video and key words.
'Estimating the health impact of vaccination against 10 pathogens in 98 low and middle income countries from 2000 to 2030' by Xiang Li et al. is published in The Lancet.
Article text (excluding photos or graphics) © Imperial College London.
Photos and graphics subject to third party copyright used with permission or © Imperial College London.
Dr Sabine L. van Elsland
School of Public Health
Communications and Public Affairs