There are a number of groups that are especially vulnerable in terms of susceptibility to influenza and barriers to accessing vaccinations. This may lead to larger problems in case of a pandemic; for example, in the H1N1 2009 outbreak in Australia, indigenous Australians, a hard to reach group, were overrepresented in rates of hospitalisation (Seale et al 2010). Hard to reach groups may have adverse health outcomes, and the complex interplay of gender and social and economic marginalisation makes this a particular issue for women (Davidson et al 2011).