Global COVID-19 vaccine hesitancy among elderly: A systematic review

Elderly infected with COVID-19 has high mortality risk, and the protection from COVID-19 vaccine is limited by vaccine hesitancy. The information of vaccine hesitancy in elderly is incomplete and fragmented. In this study, we attempt to examine the level of vaccine hesitancy in elderly and the related factors in global perspectives.

A systematic review was conducted to include observational studies of COVID-19 vaccine hesitancy in elderly from January 2020 to September 2021. Search strategies covering COVID-19 vaccine, vaccine hesitancy and elderly in four databases of PUBMED, MEDLINE, EMBASE and COCHRANE LIBRARY were adopted. Studies reporting COVID-19 vaccine hesitancy prevalence in elderly were included. A meta-analysis of the vaccine hesitancy prevalence was performed. The primary outcome is the vaccine hesitancy prevalence in elderly population globally. The secondary outcomes are the factors of COVID-19 vaccine hesitancy among elderly.

Initial 479 articles were included for screening, with 54 studies included for meta-analysis of COVID-19 vaccine hesitancy in elderly and 6 studies included for qualitative analysis of factors for vaccine hesitancy. The overall prevalence of vaccine hesitancy was 27.7 % (95 % C.I: 23.8-31.6 %). The prevalence was significantly higher in Asia than in Europe (35.3 % VS 17.9 %, p < 0.05). The vaccine hesitancy was significantly higher before the launch of the vaccine than after (30.3 % VS 18.7 %, p < 0.05). Important factors of vaccine hesitancy in elderly identified were low income, low education, perception of COVID-19 being more contagious, more vaccine side effects and lower vaccine efficacy.

COVID-19 vaccine hesitancy is an important problem in elderly, with geographical variation. Tailored policy and strategies targeting the hesitancy factors were required to promote COVID-19 vaccine to elderly.