154 million lives saved: Landmark study highlights power of vaccination

A major landmark study to be published by The Lancet reveals that global immunization efforts have saved an estimated 154 million lives – or the equivalent of 6 lives every minute of every year – over the past 50 years. The vast majority of lives saved – 101 million – were those of infants.

The study, led by the World Health Organization (WHO), shows that immunization is the single greatest contribution of any health intervention to ensuring babies not only see their first birthdays but continue leading healthy lives into adulthood.

Of the vaccines included in the study, the measles vaccination had the most significant impact on reducing infant mortality, accounting for 60% of the lives saved due to immunization. This vaccine will likely remain the top contributor to preventing deaths in the future.

Over the past 50 years, vaccination against 14 diseases (diphtheria, Haemophilus influenzae type B, hepatitis B, Japanese encephalitis, measles, meningitis A, pertussis, invasive pneumococcal disease, polio, rotavirus, rubella, tetanus, tuberculosis, and yellow fever) has directly contributed to reducing infant deaths by 40% globally, and by more than 50% in the African Region.

"Vaccines are among the most powerful inventions in history, making once-feared diseases preventable," said WHO Director-General, Dr Tedros Adhanom Ghebreyesus. "Thanks to vaccines, smallpox has been eradicated, polio is on the brink, and with the more recent development of vaccines against diseases like malaria and cervical cancer, we are pushing back the frontiers of disease. With continued research, investment and collaboration, we can save millions more lives today and in the next 50 years."

The study found that for each life saved through immunization, an average of 66 years of full health were gained – with a total of 10.2 billion full health years gained over the five decades. As the result of vaccination against polio more than 20 million people are able to walk today who would otherwise have been paralysed, and the world is on the verge of eradicating polio, once and for all.

These gains in childhood survival highlight the importance of protecting immunization progress in every country of the world and accelerating efforts to reach the 67 million children who missed out on one or more vaccines during the pandemic years.

Monumental efforts to increase access to vaccination over five decades

Released ahead of the 50^th anniversary of the Expanded Programme on Immunization (EPI) to take place in May 2024, the study is the most comprehensive analysis of the programme's global and regional health impact over the past five decades.

Founded in 1974 by the World Health Assembly, EPI's original goal was to vaccinate all children against diphtheria, measles, pertussis, polio, tetanus, tuberculosis, as well as smallpox, the only human disease ever eradicated. Today, the programme, now referred to as the Essential Programme on Immunization, includes universal recommendations to vaccinate against 13 diseases, and context-specific recommendations for another 17 diseases, extending the reach of immunization beyond children, to adolescent and adults.

The study highlights that fewer than 5% of infants globally had access to routine immunization when EPI was launched. Today, 84% of infants are protected with 3 doses of the vaccine against diphtheria, tetanus and pertussis (DTP) – the global marker for immunization coverage.

Nearly 94 million of the estimated 154 million lives saved since 1974, were a result of protection by measles vaccines. Yet, there were still 33 million children who missed a measles vaccine dose in 2022: nearly 22 million missed their first dose and an additional 11 million missed their second dose.

Coverage of 95% or greater with 2 doses of measles-containing vaccine is needed to protect communities from outbreaks. Currently, the global coverage rate of the first dose of measles vaccine is 83% and the second dose is 74%, contributing to a very high number of outbreaks across the world.

To increase immunization coverage, UNICEF, as one of the largest buyers of vaccines in the world, procures more than 2 billion doses every year on behalf of countries and partners for reaching almost half of the world's children. It also works to distribute vaccines to the last mile, ensuring that even remote and underserved communities have access to immunization services.

Thanks to vaccinations, more children now survive and thrive past their fifth birthday than at any other point in history. This massive achievement is a credit to the collective efforts of governments, partners, scientists, healthcare workers, civil society, volunteers and parents themselves, all pulling in the same direction of keeping children safe from deadly diseases. We must build on the momentum and ensure that every child, everywhere, has access to life-saving immunizations."

Catherine Russell, UNICEF Executive Director

In 2000, Gavi, the Vaccine Alliance, which includes WHO, UNICEF and the Bill & Melinda Gates Foundation (BMGF) as core founding members, was created to expand the impact of EPI and help the poorest countries in the world increase coverage, benefit from new, life-saving vaccines and expand the breadth of protection against an increasing number of vaccine-preventable diseases. This intensified effort in the most vulnerable parts of the world has helped to save more lives and further promote vaccine equity. Today, Gavi has helped protect a whole generation of children and now provides vaccines against 20 infectious diseases, including the HPV vaccine and vaccines for outbreaks of measles, cholera, yellow fever, Ebola and meningitis.

"Gavi was established to build on the partnership and progress made possible by EPI, intensifying focus on protecting the most vulnerable around the world," said Dr Sania Nishtar, CEO of Gavi, the Vaccine Alliance. "In a little over two decades we have seen incredible progress – protecting more than a billion children, helping halve childhood mortality in these countries, and providing billions in economic benefits. Vaccines are truly the best investment we can make in ensuring everyone, no matter where they are born, has an equal right to a healthy future: we must ensure these efforts are fully funded to protect the progress made and help countries address current challenges of their immunization programmes."

Immunization programmes have become the bedrock of primary health services in communities and countries due to their far reach and wide coverage. They provide not only an opportunity for vaccination but also enable other life-saving care to be provided, including nutritional support, maternal tetanus prevention, illness screenings and bed net distribution to protect families from diseases like malaria.

Since the study only covers the health impact of vaccination against 14 diseases, the number of lives saved due to vaccination is a conservative estimate and not a full account of the life-saving impact of vaccines. Societal, economic or educational impacts to health and well-being over the 50 years have also contributed to further reductions in mortality. Today, there are vaccines to protect against more than 30 life-threatening diseases.

While the HPV vaccine, which protects against cervical cancer in adults, was not included in the study, it is expected to prevent a high number of future deaths as countries work towards increasing immunization targets aimed at eliminating cervical cancer by 2030. New vaccine introductions, such as those for malaria, COVID-19, respiratory syncytial virus (RSV) and meningitis, as well as cholera and Ebola vaccines used during outbreaks, will further save lives in the next 50 years.

Saving millions more is "Humanly Possible"

Global immunization programmes have shown what is humanly possible when many stakeholders, including heads of state, regional and global health agencies, scientists, charities, aid agencies, businesses, and communities work together.

Today, WHO, UNICEF, Gavi, and BMGF are unveiling "Humanly Possible", a joint campaign, marking the annual World Immunization Week, 24-30 April 2024. The worldwide communication campaign calls on world leaders to advocate, support and fund vaccines and the immunization programmes that deliver these lifesaving products – reaffirming their commitment to public health, while celebrating one of humanity's greatest achievements. The next 50 years of EPI will require not only reaching the children missing out on vaccines, but protecting grandparents from influenza, mothers from tetanus, adolescents from HPV and everyone from TB, and many other infectious diseases.

"It's inspiring to see what vaccines have made possible over the last fifty years, thanks to the tireless efforts of governments, global partners and health workers to make them more accessible to more people," said Dr Chris Elias, president of Global Development at the Bill & Melinda Gates Foundation. "We cannot let this incredible progress falter. By continuing to invest in immunization, we can ensure that every child – and every person – has the chance to live a healthy and productive life."