Willingness to obtain COVID-19 vaccination in general population: A systematic review and meta-analysis

Background The effectiveness of vaccination campaigns in the midst of a pandemic depends on both the vaccine's effectiveness and the general population's willingness to be vaccinated. To estimate the proportion of the general population willing to get COVID-19 vaccination and to identify factors, ie, the number of COVID-19 cases and deaths, and WHO Regions contributing to the willingness rate, we conducted a systematic review and meta-analysis compliant with PRISMA 2020 guidelines. Methods A search of the existing relevant literature was conducted by means of Cochrane Library, Medline, Embase, Registers, and other sources in order to identify studies published between November 2019 and April 2021. A total of 19 studies from 11 countries that satisfied the inclusion criteria (ie, studies exclusively on the general population, and participants aged 16 years and above) were retrieved. Data extraction and quality assessment were conducted. Heterogeneity was quantified using the I2 statistic, and publication bias was assessed using funnel plots and the Egger's test. A meta-analysis and a meta-regression analysis were conducted using STATA 16.1 software. Results The pooled rate of willingness to receive a COVID-19 vaccine among the general population was calculated to be 60.1% (95% confidence interval (CI) = 51.5, 68.4). Meta-analyses showed, on the one hand, that the highest pooled willingness to get vaccinated was 73% (95% CI = 62.3, 84.1) in the studies of countries with 1000-4000 COVID-19 cases per million population and, on the other, that the same measure was 71% (95% CI = 53.2, 89.1) in countries reporting >400 COVID-19 deaths per million population. The acceptance rates also varied in different WHO regions of the world. The meta-regression analysis showed that a COVID-19 death rate of >400 per million population or higher was significantly associated (P = 0.02) with the willingness rate. Conclusions The overall willingness among the general global population to get a COVID-19 vaccine is moderately high; however, the existence of hesitancy might be a major obstacle to the global efforts to control the current pandemic. Understanding the critical factors influencing the acceptance of pandemic vaccines may help health authorities to manage emerging public health threats better.