Abstract
The availability of an effective vaccine does not equate to its use; its effectiveness primarily depends on vaccine acceptance by the targeted population. Despite the rapid development and widespread access to the COVID-19 vaccine, herd immunity is yet to be achieved, with vaccine hesitancy as a major barrier. This study sought to systematically assess the beliefs, attitudes, and acceptance towards COVID-19 vaccines, including factors contributing to vaccination hesitancy in the Eastern and Western Hemispheres. A comprehensive search of articles was conducted through Scopus, PubMed, Embase, CINAHL, Cochrane CENTRAL, and Web of Science databases for studies published from inception to May 2023 using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Our search yielded 1154, of which 21 were eligible for inclusion. The rate of willingness or intention to vaccinate varied with the geographic region, from 12% in the United States to 93.9% in China. Four studies from the Western region and two from the Eastern region reported a low acceptance rate (defined as <50%): United States (12%), Spain (48.3%), Switzerland (38.6%), Europe (multi-national, 31%), Nepal (38.3%), and Oman (43%). Overall, vaccine acceptance was low to moderate in the general population and healthcare workers (HCWs) in both Eastern and Western Hemispheres except for China which reported high acceptance (defined as >75%) among the general population and HCWs. Demographic characteristics (female, younger age, and higher education) and non-demographic factors (knowledge about the COVID-19 vaccine and its development, history of influenza vaccination, perceived susceptibility or severity of infection, and the belief that vaccines are effective in controlling the pandemic) were associated with high acceptance rates or intentions to take the COVID-19 vaccine. On the other hand, mistrust of the vaccine, its safety and effectiveness, disinformation or poor awareness of the vaccine, side effect concerns, belief in natural immunity, previous adverse experience with the vaccines, and distrust in the information sources about the COVID-19 pandemic were associated with vaccination hesitancy. For better acceptance, COVID-19 vaccination campaign strategies should be modeled based on regional political, economic, and social contexts.