Global diversity of policy, coverage, and demand of COVID-19 vaccines: a descriptive study

Abstract

Background: Hundreds of millions of doses of coronavirus disease 2019 (COVID-19) vaccines have been administered globally, but progress on vaccination varies considerably between countries. We aimed to provide an overall picture of COVID-19 vaccination campaigns, including policy, coverage, and demand of COVID-19 vaccines.

Methods: We conducted a descriptive study of vaccination policy and doses administered data obtained from multiple public sources as of 8 February 2022. We used these data to develop coverage indicators and explore associations of vaccine coverage with socioeconomic and healthcare-related factors. We estimated vaccine demand as numbers of doses required to complete vaccination of countries' target populations according to their national immunization program policies.

Results: Messenger RNA and adenovirus vectored vaccines were the most commonly used COVID-19 vaccines in high-income countries, while adenovirus vectored vaccines were the most widely used vaccines worldwide (180 countries). One hundred ninety-two countries have authorized vaccines for the general public, with 40.1% (77/192) targeting individuals over 12 years and 32.3% (62/192) targeting those ≥ 5 years. Forty-eight and 151 countries have started additional-dose and booster-dose vaccination programs, respectively. Globally, there have been 162.1 doses administered per 100 individuals in target populations, with marked inter-region and inter-country heterogeneity. Completed vaccination series coverage ranged from 0.1% to more than 95.0% of country target populations, and numbers of doses administered per 100 individuals in target populations ranged from 0.2 to 308.6. Doses administered per 100 individuals in whole populations correlated with healthcare access and quality index (R² = 0.59), socio-demographic index (R² = 0.52), and gross domestic product per capita (R² = 0.61). At least 6.4 billion doses will be required to complete interim vaccination programs-3.3 billion for primary immunization and 3.1 billion for additional/booster programs. Globally, 0.53 and 0.74 doses per individual in target populations are needed for primary immunization and additional/booster dose programs, respectively.

Conclusions: There is wide country-level disparity and inequity in COVID-19 vaccines rollout, suggesting large gaps in immunity, especially in low-income countries.

Keywords: COVID-19 vaccines; Global diversity; Vaccination policy; Vaccine coverage; Vaccine demand.

Fig. 1

Technical platforms for vaccines being administered across countries. Geographic distribution of adenovirus vectored vaccine (A), mRNA vaccine (B), inactivated vaccine (C), and protein subunit vaccine (D) administered across the globe. Since the conjugate vaccine was only used in three countries (Cuba, Iran and Nicaragua), it is not shown in the map

Fig. 2

Target populations for primary immunization, additional, and booster doses. Global distribution of target populations (regulator-approved age groups) for primary vaccination (A), an additional dose (B), and for a booster dose (C). Here, specific groups included people at risk of severe illness, occupationally at-risk populations, and international travelers. People at risk of severe illness included the elderly, residents in health centers, people with immunodeficiency disorders, people with autoimmune diseases receiving immunosuppressive therapy, people on dialysis or after organ transplantation, patients with onco-hematological diseases receiving treatment, and people with other comorbidities. Occupational-risk populations included workers at long-term care facilities, front-line health workers, and other front-line workers. People receiving other vaccines included people who receiving the one of the following vaccines: BBIBP-CorV and CoronaVac

Fig. 3

Vaccine coverage among total or target populations. Country-level full vaccine coverage among total populations (A) or target populations (B). Country-level proportion of people that received at least one dose among total populations (C) or target populations (D). Country-level cumulative doses per 100 people among total populations (E) or target populations (F). The white areas represent countries with no vaccination rollout or for which data are unavailable. The data shown here are as of 31 January 2022. Percentages of target populations that received full or at least one dose that exceed 100% may represent off-label use

Fig. 4

Vaccine coverage by age group. Proportion of age-specific populations that received full doses (A) and at least one dose (B) among total populations. The dividing line between age groups was not consistent across countries. Children refers to 0–11-year-olds; adolescent refers to 12–17-year-olds; adult refers to people aged 18–64 (Austria, Belgium, Chile, United States), 18–59 years old (Argentina, Canada, China, Czechia, Estonia, Finland, France, Georgia, Germany, Guatemala, Kenya, Malaysia, Iceland, Slovakia, Slovenia, South Africa, Sweden, Netherlands), 20–59 (Australia, Costa Rica, Israel, Italy, Singapore, Spain), or 20–64 (Denmark, New Zealand, Uruguay); and senior refers to people aged over 60 or 65 years old. Some countries only reported data for 0–19-year-olds (Israel), which we designated as an adolescent group

Fig. 5

Correlations with vaccine coverage. Correlation of cumulative doses administered per 100 people among total populations or target populations with healthcare access and quality (HAQ) index (A, B), socio-demographic index (SDI) (C, D), GDP per capita (units: dollars) after adjusting for purchasing power parity (E, F). Solid lines show linear or nonlinear fit

Fig. 6

Current demand of vaccine dose per individual in the target population. A Demand of vaccine doses for primary immunization per individual in the target population. B Demand of vaccine dose for additional/booster immunization per individual in the target population. Target population is defined as those eligible for primary or additional/booster vaccination recommended by each country’s immunization policy