World Immunization Week 2026

The International Agency for Research on Cancer (IARC) is marking World Immunization Week 2026, an initiative of the World Health Organization (WHO), with a reminder that more than 1.1 million cases of cancer were caused by vaccine-preventable infections in 2020.

IARC estimates that in 2020 almost 750 000 new cases of cancer could be attributed to infection with human papillomavirus (HPV) and almost 400 000 new cases of cancer could be attributed to infection with hepatitis B virus. Together, these represent more than 6% of all new cancer cases diagnosed that year.

Effective vaccines exist to protect against infection with HPV and hepatitis B virus, and these are not the only two infections that can contribute to cancer risk. IARC is leading cutting-edge research aimed at targeting oncogenic infections to reduce cancer incidence.

During the upcoming IARC@60 conference, there will be a dedicated session on oncogenic infections as targets amenable to cancer prevention. This unique opportunity will enable attendees to delve into the specifics of how oncogenic infections can be tackled and prevented, leading to a substantial reduction in cancer cases.

More information about oncogenic infections is available on the Global Cancer Observatory’s Cancers Attributable to Infections subsite or on the IARC website.

Visit the Global Cancer Observatory website 

Explore the Cancers Attributable to Infections subsite 

Find out more about the upcoming session at the IARC@60 conference 

Visit the WHO World Immunization Week 2026 webpage