Specific recommendation for flu vaccination for people with Down syndrome and their carers, issued by the Australian Department of Health in April 2016:
4.7 Influenza (page last updated: 08 April 2016)
Persons at increased risk of complications from influenza infection
Persons aged ≥6 months with conditions predisposing to severe influenza, such as:
... Down syndrome – Persons with Down syndrome should receive annual seasonal influenza vaccine whether or not they have congenital heart disease. This is due to the presence of anatomical abnormalities, which put them at increased risk of upper respiratory tract infections, as well as a high prevalence of other medical conditions that put them at increased risk of severe influenza.Persons who may transmit influenza to persons at increased risk of complications from influenza infection
The following groups of people can potentially transmit influenza to persons at increased risk of complications from influenza infection; vaccination of these groups is therefore recommended to protect those at risk:
... household contacts (including children ≥6 months of age) of those in high-risk groups, including providers of home care to persons at risk of high influenza morbidity
In addition, vaccination is recommended for 'residents ... of long-term residential facilities, ... due to high rates of influenza transmission and complications during outbreaks in such facilities.