--- title: Leukemia: Here's How A Childhood Vaccine Helps Ward Off Cancer description: Scientists now understand why a common childhood vaccine against HiB reduces the risk of leukemia. canonical: https://time.com/3892229/childhood-vaccine-cancer-leukemia/ author: Tessa Berenson article:opinion: false article:content_tier: free article:published_time: 2015-05-21T14:22:07.000Z article:modified_time: 2026-02-22T07:31:43.690Z article:section: Health og:title: How A Common Childhood Vaccine Helps Ward Off Cancer og:description: It reduces the risk of childhood leukemia by 20% og:url: https://time.com/3892229/childhood-vaccine-cancer-leukemia/ og:site_name: TIME og:image: https://static.time.com/v3/assets/bltea6093859af6183b/bltde093bcdab65f2d0/6988d9b9bc6cfc69913e2a3c/time-logo.jpg?branch=production og:image:width: 1200 og:image:height: 675 og:image:alt: TIME og:type: article twitter:card: summary_large_image twitter:title: How A Common Childhood Vaccine Helps Ward Off Cancer twitter:description: It reduces the risk of childhood leukemia by 20% twitter:image: https://static.time.com/v3/assets/bltea6093859af6183b/bltde093bcdab65f2d0/6988d9b9bc6cfc69913e2a3c/time-logo.jpg?branch=production --- # How a Common Childhood Vaccine Helps Ward Off Cancer ## Video: Science Cop: How Anti-Vaxxers Put Everyone at Risk [Watch (HLS stream): Science Cop: How Anti-Vaxxers Put Everyone at Risk](https://cdn.jwplayer.com/manifests/ai82XWJ8.m3u8) (2:06)  _Published 2014-09-24. TIME's Science Cop Jeffrey Kulger takes on the misinformation coming from opponents of childhood vaccinations_  by [Tessa Berenson](https://time.com/author/tessa-berenson/)  ## Tessa Berenson May 21, 2015 2:22 PM UTC  by [Tessa Berenson](https://time.com/author/tessa-berenson/)  ## Tessa Berenson May 21, 2015 2:22 PM UTC Scientists now understand why a common childhood vaccine reduces the risk of leukemia. Researchers previously knew that the vaccine against Haemophilus influenza type B, or HiB, reduces the risk of acute lymphoblastic leukemia, the most common form of childhood cancer. But now a [new study](http://www.nature.com/articles/ni.3160.epdf?referrer%5Faccess%5Ftoken=jsRxwEN-Xu2i86KYo0tPZ9RgN0jAjWel9jnR3ZoTv0OyBm0FcNmP%5FL7ZuOeo-akuhGkVWSG10z2esM5MPwtrNbBNEQ306%5FrjH2Z%5F2Il6KvMds72Mz93jL3WKW3YljIgm3V-3NL4v%5F-8rkRgletK%5FFyK11zD2TklVRl%5FTi7D1Y3aUGT90M6NE4thCoab3PxZbMKQrv9mGvUd-3FQe8iQKnIc8jFcFJl19YhOOFc3MlcKOBsZwJ84BG89J8uV8gCj5&tracking%5Freferrer=well.blogs.nytimes.com) published in _Nature Immunology_ explains why this is the case. Dr. Markus Müschen and his team on the study used a mouse model and found that recurring HiB infections, which can happen easily in children who have not been vaccinated, can cause certain enzymes to activate and push common precancerous blood cells into cancer. So, vaccines against HiB infections also protect children from this path to leukemia. Müschen [told the New York ](http://well.blogs.nytimes.com/2015/05/20/scientists-unravel-how-a-vaccine-reduces-risk-of-a-cancer/?%5Fr=0)[_Times_](http://well.blogs.nytimes.com/2015/05/20/scientists-unravel-how-a-vaccine-reduces-risk-of-a-cancer/?%5Fr=0) that the HiB vaccine, which is routinely given to children, has led to a 20% reduction in the risk for leukemia. ```json [{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://time.com/3892229/childhood-vaccine-cancer-leukemia/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/3892229/childhood-vaccine-cancer-leukemia/"},"headline":"How a Common Childhood Vaccine Helps Ward Off Cancer","datePublished":"2015-05-21T14:22:07.000Z","dateModified":"2026-02-22T07:31:43.690Z","description":"It reduces the risk of childhood leukemia by 20%","url":"https://time.com/3892229/childhood-vaccine-cancer-leukemia/","keywords":["Cancer","medicine","Vaccines"],"thumbnailUrl":"","author":[{"@type":"Person","name":"Tessa Berenson","jobTitle":null,"url":"https://time.com/author/tessa-berenson/"}],"articleSection":"Health","image":[],"publisher":{"@type":"Organization","name":"Time","url":"https://time.com/","logo":{"@type":"ImageObject","url":"https://time.com/images/logo.png","width":528,"height":156},"foundingDate":"March 3, 1923","sameAs":["https://www.facebook.com/time","https://www.instagram.com/time/?hl=en","https://twitter.com/time","https://www.pinterest.com/timemagazine"]}},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/section/health/","name":"Health"}},{"@type":"ListItem","position":2,"item":{"@id":"/tag/cancer/","name":"Cancer"}},{"@type":"ListItem","position":3,"item":{"@id":"https://time.com/3892229/childhood-vaccine-cancer-leukemia/","name":"How a Common Childhood Vaccine Helps Ward Off Cancer"}}]},{"@context":"https://schema.org","@type":"VideoObject","name":"Science Cop: How Anti-Vaxxers Put Everyone at Risk","description":"TIME's Science Cop Jeffrey Kulger takes on the misinformation coming from opponents of childhood vaccinations","thumbnailUrl":"https://cdn.jwplayer.com/v2/media/ai82XWJ8/poster.jpg?width=720","uploadDate":"2014-09-24T20:18:23.000Z","contentUrl":"https://cdn.jwplayer.com/manifests/ai82XWJ8.m3u8","embedUrl":"https://time.com/3892229/childhood-vaccine-cancer-leukemia/","duration":"PT2M6S","potentialAction":{"@type":"SeekToAction","target":"https://time.com/3892229/childhood-vaccine-cancer-leukemia/?jw_start={seek_to_second_number}","startOffset-input":"required name=seek_to_second_number"}}] ```