Immunisation has saved at least 154 million lives over the past 50 years, since the ​​World Health Organization (WHO) launched its Expanded Programme on Immunization (EPI) in 1974.

Of the lives saved, 146 million were children under five, and 101 million were babies.  Global infant deaths have reduced by 40%  and more than halved in Africa.

“That’s an average of more than 1000 a day and six every minute of every year for the past 50 years,” said WHO Director-General, Dr Tedros Adhanom Ghebreyesus, at a WHO press conference Wednesday that celebrated the program’s successes while warning of the setbacks to vaccination programmes from regional conflicts, the legacy of COVID and other risks. 

The measles vaccine has had the biggest impact on reducing infant mortality, accounting for 60% of the lives saved – 94 million.

This is according to a landmark WHO-led study, whose key findings were published on Wednesday to coincide with the start of World Immunisation Week (24-30 April).

The study used mathematical and statistical models to estimate the impact of 50 years of vaccination against EPI’s 14 priority pathogens. 

The 14 pathogens are diphtheria, Haemophilus influenzae type B, hepatitis B, Japanese encephalitis, measles, meningitis A, pertussis, invasive pneumococcal disease, polio, rotavirus, rubella, tetanus, tuberculosis, and yellow fever.

More children live to celebrate their fifth birthday

 EPI –  now renamed the Essential Programme on Immunization – celebrates its 50th next month. When it was launched fewer than 5% of infants whereas today, 84% of infants are protected with three doses of the vaccine against diphtheria, tetanus and pertussis (DTP) – the global marker for immunization coverage.

“Today more children live to celebrate their fifth birthday than any moment in history,” said Dr Ephrem Lemango, UNICEF associate director and chief of immunization, at the press briefing.

“Vaccines are among the most powerful inventions in history, making once-feared diseases preventable,” said Dr Tedros. 

“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.”

As the result of the polio vaccination, 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.

More lives are expected to be saved in the next 50 years by additional vaccines, such as the new HPV vaccine that prevents most cases of cervical cancer, and vaccines against malaria, meningitis, dengue, COVID-19, respiratory syncytial virus (RSV).

Missing doses and rising vaccine hesitancy

Despite the successes, during the COVID-19 pandemic, 67 million children didn’t receive all the vaccinations they needed between 2020 and 2022, and nearly 49 million never received a single dose, according to the WHO.  

Coverage of at least 95% of children with two measles vaccines doses is needed to protect communities from outbreaks. 

Currently, the global coverage rate of the first dose of measles vaccine is only 83% and the second dose is just 74%. Reported measles cases increased by a staggering 84% in just one year between 2022-2023. 

A rise in anti-vaccine sentiment has also seen a decrease in immunisation against measles specifically, as well as vaccination more generally, in developed countries and particularly the US. For example, 28% of Americans  believe that parents should be able to decide not to vaccinate their children (up 12 points since 2019), according a 2023 survey by the Pew Research Center.

The decline in support for vaccine requirements for children has been driven by changing views among Republicans: 57% now support requiring children to be vaccinated to attend public schools, down from 79% in 2019, according to Pew.

UNICEF, Gavi and Gates Foundation as key drivers of the success

UNICEF is one of the largest buyers of vaccines in the world, procuring more than two billion doses every year on behalf of countries and partners for reaching almost half of the world’s children. 

“This massive human achievement has only been possible through collective determination and effort led by governments and partners, with the help of scientists, healthcare workers, civil society and volunteers. Sustained cooperation and investment are essential to carry the achievements of the past half-century into the future,” said Catherine Russell, executive director of UNICEF.

In 2000, the vaccine alliance, Gavi, was created to help the poorest countries in the world increase immunisation coverage and benefit from new vaccines. 

Today Gavi has helped protect a whole generation of children and now provides vaccines against 20 infectious diseases, including HPV vaccine that protects against cervical cancer, 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 Gavi CEO Dr Sania Nishtar. 

“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.”

New vaccine opportunities for meningitis, malaria and dengue

The rollout of a new vaccine for meningitis, which immunises against five bacterial strains at once, offers the first “real hope of being able to eliminate meningitis as a public health problem,” said Tedros. The vaccine was launched just last month by Nigeria in its northern states where officials aim to vaccinate 1 million people hit hard by meningitis recently.  He noted that he would be joining global health leaders in Paris Friday for a first-ever high level meeting on defeating meningitis.

“The defeating meningitis by 2030 roadmap requires an initial investment of 130 million US dollars,” said Tedros. “Which is frankly loose change compared to the return that investment will deliver as well as preventing over $900,000 and nearly 3 million cases of meningitis by 2030. He added that “defeating meningitis would save billions of dollars in health costs and lost productivity – and as part of an integrated primary health care program can also help to combat antimicrobial resistance (AMR).”

Two new malaria vaccines are also being rolled out in half a dozen African countries, with many more states planning to join the campaign, said Tedros.  Malaria vaccines, he said, could “save tens of thousands of young lives every year” in the case of a disease that now kills some 608,000 people annually.

Finally, vaccines are playing a novel role in the response to a widening dengue outbreak, including more than 5.2 million cases reported in the Americas over just the first quarter of 2024 – more than all of 2023 combined.

“Last year, WHO recommended use of a new dengue vaccine for children aged six to 16 in areas where Dengue is present,” said Tedros.  “Countries including Brazil are now using the vaccine are now using the vaccine – although the supplies constraints and costs are still releatiely high.”

DRC declares mpox a health emergency – finally setting stage for vaccine rollout

Meanwhile, the Democratic Republic of Congo (DRC) two weeks ago declared its swelling mpox outbreak as a national health emergency – finally setting the stage for introduction of two novel mpox vaccines against a worrisome rise in deadly Clade 1 cases of the disease, particularly among children.

So far no vaccines have been used at all in the DRC outbreak – due to multiple hurdles ranging from global supply lines to bureaucratic barriers in a country wracked by armed conflicts, poverty and multiple disease challenges.

“Now that the government two weeks ago determined that the mpox outbreak in the country constitutes a health emergency, the Ministry of Health has a direction.  And they have issued their statement that they intend to introduce vaccines in the country,” said WHO’s Dr Rosamund Lewis. “So the next step is the vaccine assessment by the national regulatory authority of the two vaccines that the National Immunization Technical Advisory Group has recommended, and open immunization strategies.”

Those vaccines include a Japanese-made mpox vaccine,  LC16 KMB, which is approved for use in children, and the Bavarian Nordic’s MVA-BN vaccine, which has not yet been approved for child use and requires two jabs to be effective.

“I think it’s important to note that the MVA-BN vaccine is very similar to the vaccine for Ebola and that does have authorization for children. So we know a lot about the safety of these vaccines in children,” said Dr Kate O’Brien, director of WHO’s Immunization Programme. Even so, it will be important to conduct more studies simultaneously with rollout to determine how the vaccines can best be deployed among at-risk groups.

“It’s really important as the rollout of vaccine happens, that it’s done in such a way that the information is collected in a scientific way, so that we really strengthen the evidence that will lead to a better understanding of exactly how the vaccines can best be used,” O’Brien said.

‘Humanly possible’ campaign

Also on Wednesday, WHO, UNICEF, Gavi, and the Bill and Melinda Gates Foundation (BMGF) launched a worldwide communication campaign on Wednesday, Humanly Possible, which calls on world leaders to advocate, support and fund vaccines and the immunization programmes that deliver these lifesaving products.  The campaign follows on WHO’s announcement last year of The Big Catchup – a strategy that aims to recoup ground lost during the COVID pandemic, in terms of immunization coverage. 

“It’s inspiring to see what vaccines have made possible over the last 50 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, BMGF president of Global Development 

“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.”

• with reporting by Elaine Ruth Fletcher 

Image Credits: UNICEF, Gavi.