- What is the clinical effectiveness of high dose influenza vaccine in older adults or adults who are immunocompromised?
- What is the cost-effectiveness of high dose influenza vaccine in older adults or adults who are immunocompromised?
- What are the evidence-based guidelines associated with the use of high dose influenza vaccine in older adults or adults who are immunocompromised?
Three systematic reviews, four randomized controlled trials (RCTs), four economic evaluations, and one guideline were identified regarding high-dose influenza vaccination. For immunocompromised individuals, high-dose trivalent inactivated influenza vaccine (HD-IIV3) appeared to have no statistically significant difference in safety when compared to standard dose trivalent inactivated influenza vaccine (SD-IIV3). This evidence was very limited, with methodological concerns and different and heterogeneous populations for each study.For elderly adults 65 years of age or older, HD-IIV3 appeared to have similar or higher effectiveness at reducing influenza illnesses, hospitalization, and mortality, when compared to SD-IIV3, with no statistical differences in adverse events. HD-IIV3 also appeared to be cost effective from both a Canadian and US perspective, when compared to SD-IIV3, no vaccination, and standard dose quadrivalent IIV. One high-quality evidence based guideline was identified in the literature, recommending HD-IIV3 for elderly adults 65 or older over standard dose vaccines on an individual level. On a programmatic level, all vaccine strategies, including high dose, were recommended. There were no evidence based guidelines or cost-effectiveness studies focusing on immunocompromised populations.