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World Immunization Week 2024

From April 24-30, public health officials raise awareness about the protection vaccines provide and their potential to improve global health. This year, the World Health Organization (WHO) celebrates 50 years of its Expanded Programme on Immunization.

Girl receives a vaccination in her upper arm.

Each year at the end of April, the World Health Organization (WHO) celebrates World Immunization Week. This week serves as a reminder of the role that vaccines play in public health in protecting people against diseases.

Established in 2012, World Immunization Week was created to raise awareness about the importance of immunizationand to encourage people to work in their communities to protect people’s health through vaccination.

Immunization is one of the most cost-effective public health interventions; the U.S. Centers for Disease Control (CDC) estimates that each dollar spent on immunization programs in low- and middle-income countries brings a $52 USD return on investment. Still, vaccines remain out of reach for millions worldwide due to their location or socioeconomic standing, according to the WHO. This lack of access not only puts the health of individuals at riskit also poses a threat to public health on a global level.

This year’s theme for World Immunization Week is “Humanly Possible: Saving lives through immunization.” This theme celebrates the 50-year anniversary of the Expanded Programme on Immunization (EPI), a program established by the WHO to provide all children—regardless of their socioeconomic status or where they live—access to vaccines.

"In just five decades we went from a world where the death of a child was something many parents feared, to a world where every child – if vaccinated – has a chance to survive and thrive,” the WHO says on its website.

At the time of its founding, EPI aimed its efforts on protecting children against six illnesses associated with childhood: diphtheria, measles, pertussis, polio, tetanus and tuberculosis. Today, operating as the Essential Program on Immunization, the EPI has broadened its original goal to immunizing all people, regardless of age, against a wide range of diseases.

In recent years, vaccines have played a critical role in controlling and even eradicating infectious diseases. The eradication of smallpox through a global vaccination campaign stands as an important achievement in public health. Vaccines have also helped substantially reduce the rates of several other diseases, including diphtheria, measles, mumps, polio, rubella and tetanus.

Nevertheless, much work remains to increase immunization against vaccine-preventable diseases—and to maintain the progress that has been made. The spread of COVID-19 negatively impacted global childhood vaccination rates; since then, rates have risen, but have yet to reach vaccine coverage levels recorded in 2019. The theme of World Immunization Week last year—“the Big Catch-Up”—highlighted a campaign by the WHO and its partners to encourage immunizations for children who missed out on their routine vaccinations in the early period of the COVID-19 pandemic.

Aside from COVID-19, conflicts around the world, economic declines and vaccine hesitancy—the reluctance or refusal of vaccines—are other reasons why vaccination rates are falling short of public health immunization goals. The WHO in 2019 identified vaccine hesitancy as one of 10 threats to global health. Outbreaks of diphtheria and measles have arisen recently, causing ongoing concern.

Learn more about the EPI initiative on the WHO website.