Vaccines have proven to be one of the most effective public health interventions , saving millions of lives worldwide. Over the past 50 years, vaccines have prevented an astounding 154 million childhood deaths , a significant achievement made possible by steadily increasing vaccination coverage against deadly pathogens such as polio , diphtheria , tetanus , measles , tuberculosis , and whooping cough .
Since 1980 , vaccination rates against these microorganisms have doubled , and the number of babies without any vaccination has been reduced by three-quarters . However, this progress also masks a concerning trend that threatens its sustainability. Since 2010 , vaccination rates have stagnated or even declined in many countries , as reported in a new study analyzing data from 204 nations published in the scientific journal The Lancet.
If this trend continues, warn the authors of the study, the set vaccination targets for 2030 will not be met. “Despite monumental efforts over the last 50 years, progress is far from universal. A significant number of children remain unvaccinated,” said Jonathan Mosser , from the University of Washington, highlighting that global inequalities , challenges from the COVID-19 pandemic , and rising levels of misinformation and vaccine hesitancy have all contributed to a drop in immunization momentum.
The study reveals alarming examples of this worrying trend. Between 2010 and 2019 , vaccination against measles decreased in 100 of the 204 countries studied. Additionally, in 21 out of 36 high-resource countries , there were decreases in vaccination rates for at least one dose against diphtheria, tetanus, whooping cough, measles, polio, or tuberculosis.
Situation in Spain
In Spain , the study indicates a decline in vaccination coverage from 2019 to 2023 . The vaccination rates recorded in 2019 were 98% , which dropped to 96.7% five years later. The number of children without any basic vaccine doses, such as the combined immunization against diphtheria, tetanus, and whooping cough (also known as DTaP ), rose from 7,390 to 10,734 , as reported.
Jaime Pérez , president of the Spanish Association of Vaccinology, emphasizes that “we have high vaccination coverage among the pediatric population in Spain, which is maintained. It’s true that we have coverage that does not meet vaccination goals (like measles), but this is often due to registration issues rather than actual vaccination deficits.” However, he points out that in recent years, there has been a noticeable increase in the population rejecting vaccines, an issue that was not prevalent before COVID-19. “Thus, it is crucial to improve communication on results and continue emphasizing the importance of vaccination,” he stresses.
The COVID-19 pandemic has impacted the challenges vaccinations were already facing since the beginning of the century. In fact, the study estimates that 15.6 million children missed the three doses of the combined vaccine against diphtheria, tetanus, and whooping cough or failed to receive vaccines against measles between 2020 and 2023 ; 15.9 million missed polio immunization, while 9.18 million were left without tuberculosis vaccination.
As of 2023 , half of the 15.7 million children without even basic vaccines were concentrated in just eight countries , mostly situated in sub-Saharan Africa . These nations include Nigeria , India , Democratic Republic of Congo , Ethiopia , Somalia , Sudan , Indonesia , and Brazil .
The study indicates that to achieve the 2030 goal of halving the number of children without basic vaccines compared to 2019 , efforts must be doubled . Current estimates suggest that only the vaccination against diphtheria, tetanus, and whooping cough has any possibility of reaching a 90% global coverage, and only if the most optimistic scenarios are realized.
The analysis highlights the persistence of outbreaks of vaccine-preventable diseases, citing polio cases recorded in Pakistan , Afghanistan , and Papua New Guinea , and showing disturbing data regarding the state of measles in Europe and other regions of the world.
The Measles Case
In 2024 , these infections increased tenfold in the European Union and the European Economic Area . Furthermore, the United States has seen over 1,000 confirmed measles cases across 30 states , surpassing the totals for all of 2023 .
Spain has also registered outbreaks and sporadic infections in recent months. Specifically, 217 cases were confirmed in 2024 , according to the Advisory Committee on Vaccines of the Spanish Pediatric Association, which notes that these numbers are “significantly higher than during the 2021 to 2023 period.” In the first quarter of 2025 , 179 additional cases were detected (57 imported, 69 linked, and 53 of unknown or investigatory origin), with the greatest incidence in Andalusia , Basque Country , Catalonia , and Melilla .
Despite the rise in cases, Pérez reassures that, in our country, “it is not expected that measles will return to significant levels.” However, he clarifies that achieving high vaccination coverage against the disease is essential for its elimination. He warns that if these numbers are not reached, “we could face challenges in our elimination objectives, leading to an increase in outbreaks and the risks they pose to affected individuals. On average, 20% of measles cases present complications , especially pneumonia, and sadly, the disease can be fatal in 1-3 out of every 1,000 cases ,” he reminds us.
The report’s authors call for measures to address the inequalities and challenges posed by vaccination at a global scale, a sentiment echoed by Pérez. “As the report indicates, we have taken steps backward in certain vaccines, compounded by the lack of cooperation from the USA in international public health, which could make the future scenario even more concerning,” he laments.
Among the most pressing challenges , the expert cites the necessity to “maintain childhood vaccination coverage, improve adult vaccination rates, successfully integrate new vaccines in a timely manner, and engage the population through showing the health results that vaccines ensure.” Regarding the latter, Pérez recalls that immunization with the monoclonal antibody against RSV (respiratory syncytial virus) helped prevent 10,000 hospitalizations in Spain. “This is the kind of message we need to convey to our population,” he concludes. “Vaccines are safe and effective.”
The Spanish Association of Vaccinology, Opposing the Dismissal of 17 Experts in the USA
The Spanish Association of Vaccinology expressed on Tuesday its opposition to the dismissal of 17 members of the Advisory Committee on Immunization Practices in the United States (ACIP) carried out by Health Secretary Robert F. Kennedy Jr.
This rapid and irregular replacement of committee members, who have proven expertise, has been denounced by vaccinologists, who also remark that the new appointments are predominantly filled by individuals with little experience in vaccinations or those who maintain a negative view of them. “This makes it quite difficult to expect an objective and expert perspective on immunizations,” they stress.
The Spanish organization has joined the protest of more than 20 American scientific societies , including the American Academy of Pediatrics and the American Academy of Family Physicians , emphasizing that “vaccines are for everyone—regardless of political affiliation. Politics should never interfere with science, neither against it nor appropriating it.”