The Lancet Infectious Disease
May 2010  Volume 10  Number 5  Pages 289 – 366
http://www.thelancet.com/journals/laninf/issue/current

The Xs and Y of immune responses to viral vaccines
Sabra L Klein, Anne Jedlicka, Andrew Pekosz

Preview
The biological differences associated with the sex of an individual are a major source of variation, affecting immune responses to vaccination. Compelling clinical data illustrate that men and women differ in their innate, humoral, and cell-mediated responses to viral vaccines. Sex affects the frequency and severity of adverse effects of vaccination, including fever, pain, and inflammation. Pregnancy can also substantially alter immune responses to vaccines. Data from clinical trials and animal models of vaccine efficacy lay the groundwork for future studies aimed at identifying the biological mechanisms that underlie sex-specific responses to vaccines, including genetic and hormonal factors.