Derivation of study population from online cohort of MSM, United States, October–December 2010.

<p>Derivation of study population from online cohort of MSM, United States, October–December 2010.</p

Reasons for lack of hepatitis B vaccination among 323 unvaccinated, HIV- and hepatitis B-negative men who have sex with men, United States, October–December 2010.

a<p>Percents may sum to more than 100 because respondents could specify more than 1 reason why they were not vaccinated against hepatitis B.</p>b<p>Percents sum to more than 100 due to rounding.</p>c<p>103 respondents not vaccinated against hepatitis B either did not specify a reason for not being vaccinated, did not know why they were not vaccinated or, if they specified more than 1 reason for not being vaccinated, did not specify a main reason.</p