Vaccination Alters the Immune System

Feinberg School of Medicine, Northwestern University

Sunday May 31, 2009

A new study published online on Nov 15, 2008 and scheduled to appear in the July 2009 issue of Cancer Causes Control suggests that some vaccines may increase risk of cancers such as non-Hodgkin lymphoma, while others may reduce the risk.

The study led by H. A. Lankes and colleagues at Feinberg School of Medicine of Northwestern University showed influenza vaccination was linked to a 53 percent increase in the risk of NHL.

Factors that alter the immune system have been known to affect the risk of non-Hodgkin lymphoma. But previous studies are inconsistent.

Lankes and colleagues analyzed data on 387 patients with NHL and 535 controls who were enrolled in a study conducted in Nebraska between 1999 and 2002. Considered information included vaccination for tetanus, polio, influenza, smallpox, and tuberculosis, as well as important environmental factors – data collected by telephone interview.

They found that study participants who had an influenza vaccine at any time were at a 98 percent increased risk of follicular lymphoma and at an 88 percent increased risk of diffuse large B cell lymphoma.

Those who received a polio or smallpox vaccination were at a 41 reduced risk of NHL or at a 29 percent reduced risk.

An analysis by histogic subtypes showed that the polio vaccine was associated with a 45 percent lowered risk of follicular lymphoma, and a 71 percent lower risk of chronic lymphocytic leukemia/small lymphocytic lymphomas. And the smallpox vaccination was linked to a 59 percent lowered risk of marginal zone lymphoma.

The tetanus and tuberculosis vaccinations were not associated with risk of the cancers of concern.

(By David Liu and edited by Rachel Stockton)