Vaccination History and Risk of Lymphoma and Its Major Subtypes.

ABSTRACT Background: Vaccinations have been hypothesized to play a role in lymphoma etiology, but there are few studies, mixed results and limited data on lymphoma subtypes. Herein, we investigate the association of vaccinations with risk of major lymphoma subtypes. Methods: We studied 2461 lymphoma cases and 2253 controls enrolled from 2002-2014. Participants self-reported history of vaccinations against hepatitis A, hepatitis B, yellow fever and influenza. Polytomous logistic regression was used to estimate odds ratio (OR) and 95% confidence intervals(CI), adjusting for potential confounders. Results: After multivariable adjustment, vaccination against influenza was inversely associated with lymphoma (OR=0.82,95%CI:0.66-1.02), which was stronger for last vaccination 1+ years before enrollment (OR=0.71,95%CI:0.56-0.91) and for >5 influenza vaccinations (OR=0.56,95%CI:0.46-0.68). Ever vaccination against hepatitis A (OR=0.81,95%CI:0.66-1.00) but not hepatitis B (OR=0.97,CI:0.81-1.18) was associated with lymphoma risk, although more recent vaccinations were inversely associated with lymphoma risk for both hepatitis A (<6 years before enrollment, OR=0.56,95%CI:0.40-0.77) and hepatitis B (<9 years before enrollment, OR=0.72,95%CI:0.55-0.93). Ever vaccination against yellow fever was inversely associated with risk (OR=0.73,95%CI:0.55-0.96) and this did not vary by time since last vaccination. While there was no overall statistical evidence for heterogeneity of vaccination history by lymphoma subtype, the only statistically significant inverse associations were observed for influenza and yellow fever vaccinations with diffuse large B-cell and follicular lymphoma. Conclusions: Selected vaccinations were inversely associated with lymphoma risk, with time since last vaccination relevant for some of these vaccines. Impact: Vaccinations against hepatitis A, hepatitis B, yellow fever and influenza are unlikely to increase lymphoma risk.