COVID-19 Vaccine Acceptance among Low- and Lower-Middle-Income Countries: A Rapid Systematic Review and Meta-Analysis

"As global vaccination efforts continue, this study could provide initial steps to facilitate the planning of ongoing vaccination programs and enhance vaccine uptake in developing countries."

Vaccination hesitancy and acceptance have emerged as prominent issues in the global fight against COVID-19. Low- and lower-middle-income countries (LMICs) generally show higher willingness to accept vaccinations than higher-income countries. However, as COVID-19 mortality rates in LMICs have been consistently lower than those in higher-income countries, LMIC residents might not acknowledge the risks of the disease and, thus, may be less willing to receive the COVID-19 vaccine, even when available. This paper describes a rapid systematic review and meta-analysis aiming to estimate COVID-19 vaccine acceptance and hesitance rates among the people of LMICs.

Conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement (PRISMA) recommendations, this review involved a systematic search of Medline (via PubMed), Web of Science, and Scopus on August 22 2021. A total of 452 articles were identified in preliminary searches; 36 studies met the inclusion criteria and were included in the review. The researchers undertook quality assessments of the included studies using the Joanna Briggs Institute critical appraisal tool: Each of the 36 studies was categorised into the high-quality category for observational studies. They then performed a meta-analysis to estimate pooled acceptance rates with 95% confidence intervals (CI).

A total of 83,867 respondents from 33 countries were studied. Most of the studies were conducted in India (n=9), Egypt (n=6), Bangladesh (n=4), or Nigeria (n=4). The pooled-effect size of the COVID-19 vaccine acceptance rate was 58.5% (95% CI: 46.9, 69.7, I2 = 100%, 33 studies), and the pooled vaccine hesitancy rate was 38.2% (95% CI: 27.2-49.7, I2 = 100%, 32 studies). In country-specific sub-group analyses, India showed the highest rates of vaccine acceptancr (76.7%, 95% CI: 65.8-84.9%, I2= 98%), while Egypt showed the lowest rates of vaccine acceptance (42.6%, 95% CI: 16.6-73.5%, I2= 98%).

Meta-estimates of COVID-19 vaccination acceptance rates and their factors are presented in Figure 6 in the paper. Sex, residence, marital status, education, occupation, presence of chronic disease(s), healthcare worker status, previous vaccine history, and perceived risk of COVID-19 were checked as deterministic variables. Only being male (n = 17 studies, odds ratio (OR) = 1.2, 95% CI: 1.0-1.6, I2 = 91.6%) and perceived risk of COVID-19 infection (n = 3 studies, OR = 2.4, 95% CI = 1.1-5.5, I2 = 93.1%) had high pooled odds ratios that were significantly associated with vaccination acceptance.

Reflecting on the findings, the researchers note that the observed vaccine acceptance rate of 59% is much lower than global estimates in earlier reviews that included studies only through April 2021. Other reviews have shown vaccine acceptance rates have varied over the course of the pandemic. For example, a global review found acceptance rates increased from 57% in April 2020 to 75% in June 2020 in the United States.

The researchers suggest that the moderate levels of vaccine hesitancy in the current study might be explained by the low severity of COVID-19 cases in LMICs, negative perceptions of healthcare quality, exposure to widespread misinformation in social media, and low trust in governmental agencies. The study's finding of low acceptance and high hesitancy in African countries (e.g., Egypt, Uganda) could be due to the fact that people in Africa have historically had higher vaccine hesitancy rates. For example, the Nigerian boycott of the polio vaccine during the early 2000s resulted when religious and political leaders feared that the vaccine could be deliberately contaminated with anti-fertility agents and HIV virus. Also, misconceptions and misinformation about COVID-19 have been widespread across the continent, and many African communities have poor health-seeking behaviours due to spiritual considerations.

The finding that male gender was a significant predictor of vaccine acceptance in LMICs may be explained by factors such as lower COVID-19-related risk perceptions among women. Regarding the risk perception findings, the researchers point to the Health Belief Model (HBM), which suggests that individuals who fear COVID-19 are more willing to get vaccinated due to the perceived benefits.

Based on the findings, the researchers suggest developing-country-specific interventions to increase the acceptance rates in LMICs. "[T]he government of each country should establish public faith in vaccines at the national level. At the same time, governments should be aware of anti-vaccination movements among people in LMICs resulting from misconception and misinformation in social media or other factors (i.e., spiritual ones) since these could limit vaccine acceptance....Understanding the factors that may influence vaccination intentions (i.e., being male, perceived risk of COVID-19) may also allow greater effectiveness of vaccination programs."

Future research directions include focusing on longitudinal changes in COVID-19 vaccine hesitancy in LMICs. The present study "provides initial guidance to understanding patterns in vaccination acceptance over time." In addition, "[m]ost of the studied populations in the included studies were from the general population. Future studies should also focus on estimating vaccine acceptance rates and determining underlying hesitancy factors among other groups, such as healthcare workers, pregnant women, children, and patients with chronic disease."

In conclusion: "Vaccine hesitancy could be addressed by community leaders, community mobilization efforts, health care professional training, non-monetary incentives, and mass media campaigns to enhance knowledge and awareness about vaccinations and immunization. Prioritizing vaccine distribution in LMICs could yield significant gains in global vaccination coverage."