Mortality resulting from influenza (flu) virus infections occurs primarily in the elderly through declining immunity.
It is easy to understand that progressive age and contracting numbers of naïve T cells go hand in hand with declining immunity.
A prohibitive roadblock using mouse infection models stems from long‐time intervals required for declining immunity to take hold (≥15 20 months) (Lages et al., 2008; Decman et al., 2012).
Reported HFRS patients in 60 70 age group, of which people with declined immunity, accounted for 9.8% of the total cases in 2006, and had risen to 13.0% in 2012.
To relate sarcopenia, obesity, and declining immunity in aging, we speculated that these conditions are linked processes, which are controlled by adipose tissue-derived and skeletal muscle-derived cytokines, known as adipokines and myokines, respectively.
Declining immunity level over years could result in an increasing proportion of susceptibles in those adults who were vaccinated in childhood and thus being at risk of clinical hepatitis A when infected.
Reactivation of TB is typically associated with an age-related decline in immunity, immunosuppression or immune-compromising diseases such as HIV.
In addition, the decline in immunity in elderly persons particularly affects cell-mediated immunity, which is vital for protection against coccidioidomycosis (33, 35 ).
The main contributing factor to this is the age-related decline in immunity which interferes with the ability of older adults to generate sufficient antibody responses to vaccination, which ultimately weakens their resistance against the flu.
Decline in immunity associated with aging {Arlt, 2004 #292 Kurz, 2004 #291} increases chronic reactivation of herpesvirus [86].
