Response of Older Adults to Influenza Vaccination With Regard to Cytomegalovirus (CMV) Status

The study is being undertaken to evaluate responses to seasonal influenza vaccine in older adults with respect to their CMV status. CMV is cytomegalovirus and is an organism that infects many people, but does not usually cause disease in the individual unless they are immunocompromised i.e. their immune system is not working well such as in the case of HIV infection. CMV is believed to have infected up to 80% of individuals in the age group we will be looking at in our study and we are interested in whether this infection affects their responses to vaccination.