COVID-19 Vaccine Hesitancy: Umbrella Review of Systematic Reviews and Meta-Analysis

"The unprecedented emergence of the COVID-19 pandemic necessitated the development and global distribution of vaccines, making the understanding of global vaccine acceptance and hesitancy crucial to overcoming barriers to vaccination and achieving widespread immunization."



Rooted in a complex interplay of factors, including safety apprehensions, distrust toward health advisories, cultural nuances, and the deluge of misinformation, COVID-19 vaccine hesitancy has been observed across diverse geographies. These disparities in vaccine acceptance, if unchecked, have the potential to impede global strides toward achieving herd immunity, a critical milestone in the fight against the pandemic. This umbrella review synthesises findings from systematic reviews and meta-analyses to provide insights into global perceptions on COVID-19 vaccine acceptance and hesitancy across diverse populations and regions.



The researchers conducted a literature search across major databases to identify systematic reviews and meta-analysis that reported COVID-19 vaccine acceptance and hesitancy. Inclusion criteria were met by 78 meta-analyses published between 2021 and 2023. The AMSTAR-2 (A Measurement Tool to Assess Systematic Reviews) criteria were used to assess the methodological quality of included systematic reviews. The quality assessment revealed 19 high-quality, 38 moderate-quality, 15 low-quality, and 6 critically low-quality meta-analyses. Meta-analysis was performed using STATA 17 with a random effect model. The data synthesis is presented in the paper in a table format and via a narrative.



The analysis revealed a moderate vaccine acceptance rate of 63% (95% confidence interval (CI) 0.60%-0.67%) in the general population, with significant heterogeneity (I2 = 97.59%). Higher acceptance rates were observed among healthcare workers and individuals with chronic diseases, at 64% (95% CI 0.57%-0.71%) and 69% (95% CI 0.61%-0.76%), respectively. However, lower acceptance was noted among pregnant women, at 48% (95% CI 0.42%-0.53%), and parents consenting for their children, at 61.29% (95% CI 0.56%-0.67%). The pooled vaccine hesitancy rate was 32% (95% CI 0.25%-0.39%) in the general population.



Per the researchers, the "high heterogeneity observed across studies denotes the existence of multiple influencing factors, including cultural, socioeconomic, educational, and individual beliefs, which vary extensively within and across populations...The variations may also reflect the differences in study designs, populations, and time frames, emphasizing the need for standardization in future research to facilitate comparability and generalizability..."



Furthermore: "The disparities in vaccine acceptance and hesitancy across populations are emblematic of the intricate tapestry of perceptions, beliefs, and information access that characterize the global populace." These disparities "accentuate the need for continuous research to understand evolving vaccine perceptions and to address the unique concerns and needs of diverse populations, thereby aiding in the formulation of effective and inclusive vaccination strategies."



For instance, the acceptance and hesitancy rates in specific communities, such as Black or African American and Chinese communities, underscore the impact of cultural and community nuances on vaccine perceptions. According to the researchers, culturally sensitive approaches, community engagement, and efforts to address systemic barriers are essential to enhancing vaccine acceptance in such communities. The 80% acceptance rate in Chinese communities may be indicative of the influence of community norms, government policies, and public health campaigns in shaping vaccine perceptions. "Understanding the sociocultural dynamics and leveraging community influences can be instrumental in developing effective strategies to enhance vaccine acceptance in different cultural contexts."



Thus, this review emphasises the necessity for population-specific, culturally sensitive interventions and clear, credible information dissemination to foster vaccine acceptance. A one-size-fits-all communication approach may not address the unique concerns, misconceptions, and information needs of different demographic groups. For example, the lower acceptance rates in parents consenting for their children necessitate interventions addressing parental concerns about vaccine safety and efficacy in children. Engaging paediatricians and child healthcare providers in vaccine advocacy can potentially alleviate parental apprehensions and foster trust.



On that note, healthcare workers, with an acceptance rate of 64%, play a crucial role in shaping public perceptions and behaviours regarding vaccination. As trusted sources of health information, they can address concerns, clarify misconceptions, and advocate for the benefits of vaccination. Their interactions with patients and communities can significantly influence vaccine acceptance, especially in populations with high hesitancy levels, such as pregnant women and parents. However, the hesitancy rate of 29% among healthcare workers is concerning, as it can potentially impact their vaccine advocacy efforts. "Addressing the concerns and information needs of health care workers is imperative to fostering confidence in vaccines and enhancing their role as vaccine advocates."



The researchers conclude by suggesting that future research should focus on exploring the underlying factors influencing vaccine acceptance and hesitancy in diverse populations and contexts. Qualitative studies can provide in-depth insights into individual beliefs, perceptions, and information needs, enabling the development of targeted interventions. Longitudinal studies can assess the temporal variations in vaccine perceptions and the impact of evolving information landscapes on vaccine-related behaviours.



Full list of authors, with institutional affiliations: Tahani Al Rahbeni, PhD, Riyadh Elm University; Prakasini Satapathy, PhD, Saveetha University; Ramaiah Itumalla, PhD, The Apollo University; Roy Rillera Marzo, MD, Curtin University; Khalid A L Mugheed, PhD, Riyadh Elm University; Mahalaqua Nazli Khatib, MD, Datta Meghe Institute of Higher Education; Shilpa Gaidhane, MD, Datta Meghe Institute of Higher Education; Quazi Syed Zahiruddin, MD, Datta Meghe Institute of Higher Education and Research; Ali A Rabaan, PhD, Johns Hopkins Aramco Healthcare,  Alfaisal University, and The University of Haripur; Hayam A Alrasheed, PhD, Princess Nourah bint Abdulrahman University; Maha F Al-Subaie, PhD, Johns Hopkins Aramco Healthcare and Dr Sulaiman Alhabib Medical Group; Nawal A Al Kaabil, PhD, Khalifa University and Abu Dhabi Health Services Company; Mohammed Alissa, PhD, Prince Sattam bin Abdulaziz University; Amani Ahmed A L Ibrahim, PhD, Jubail General Hospital; Hussain Abdulkhaliq Alsaif, PhD, Batterjee Medical College; Israa Habeeb Naser, PhD, AL-Mustaqbal University; Sarvesh Rustagi, PhD, Uttaranchal University; Neelima Kukreti, PhD, Graphic Era Hill University; Arkadiusz Dziedzic, PhD, Medical University of Silesia