World Immunization Week runs April 24–30, 2027, when the World Health Organization rallies countries to close the gaps in who gets vaccinated.
The Last Week of April
Every year, April 24 to 30.
The World Health Organization started and leads it. Its campaign archive lists editions going back to 2012, a year themed “Protect your world: Immunization saves lives.”
Because the dates are fixed, the week can start on any day of the week. In 2027, it runs Saturday to Friday.
A WHO Campaign
WHO works with national governments all year to build strong immunization programs. The week puts that work in public view.
Each year gets a fresh theme. For 2026, it was “For every generation, vaccines work.”
WHO’s aim stays the same: to “promote the use of vaccines to protect people of all ages against disease.”
Where Coverage Stands
Most children are reached. In 2025, 85% of infants, about 110 million, got all three doses of the diphtheria-tetanus-pertussis vaccine.
Millions still miss out. WHO counted 13.5 million “zero-dose” children in 2025, kids who got no routine vaccines at all.
Measles shows the gap. Coverage was 84% for the first dose and 77% for the second, below what’s needed to stop outbreaks.
Polio is nearly gone. Wild poliovirus remains endemic only in Afghanistan and Pakistan.
Protection against it is uneven, though. First-dose polio vaccine reached 86% of infants, but only 74% got two or more doses.
Yellow fever vaccine is now used in 38 of the 40 countries and territories at risk.
HPV vaccine use is climbing fast. First-dose coverage among girls rose from 17% in 2019 to 33% in 2025, against a 90% target for 2030.
New tools keep arriving. By 2025, 25 African countries had introduced malaria vaccines.
Other vaccines lag. Global coverage for hepatitis B reached 84%, but only 43% of newborns got the birth dose.
Regional gaps are wide. Hepatitis B birth-dose coverage was 77% in WHO’s Western Pacific region but just 11% in Africa.
Rotavirus vaccine, which prevents a common cause of severe diarrhea, reached 61% of children, and pneumococcal vaccine 71%.
Ways to Take Part
- Check your family’s vaccine records and book any missed doses.
- Ask your doctor if you’re due for any adult boosters.
- Post the year’s theme and ask friends to check their vaccine cards.
- Ask about HPV vaccine for preteens at their next checkup.
- Support groups that deliver vaccines to children in hard-to-reach places.
Frequently Asked Questions
Is World Immunization Week an official observance?
It’s a WHO campaign, so it’s official at the global level.
What is a zero-dose child?
A child who hasn’t received any routine vaccine, starting with the first DTP shot.
How many countries offer HPV vaccine?
162, by WHO’s latest count.