Assessing Inequities in COVID-19 Vaccine Roll-Out Strategy Programs: A Cross-Country Study Using a Machine Learning Approach

Abstract

After the start of the COVID-19 pandemic and its spread across the world, countries have adopted containment measures to stop its transmission, limit fatalities, and relieve hospitals from straining and overwhelming conditions imposed by the virus. Many countries implemented social distancing and lockdown strategies that negatively impacted their economies and the psychological wellbeing of their citizens, even though they contributed to saving lives. Recently approved and available, COVID-19 vaccines can provide a really viable and sustainable option for controlling the pandemic. However, their uptake represents a global challenge due to vaccine hesitancy and logistic–organizational hurdles that have made its distribution stagnant in several developed countries despite several appeals by the media, policy- and decision-makers, and community leaders. Vaccine distribution is also a concern in developing countries, where there is a scarcity of doses. The objective of the present study was to set up a metric to assess vaccination uptake and identify national socio-economic factors influencing this indicator. We conducted a cross-country study. We first estimated the vaccination uptake rate across countries by fitting a logistic model to reported daily case numbers. Using the uptake rate, we estimated the vaccine roll-out index. Next, we used Random Forest, an “off-the-shelf” machine learning algorithm, to study the association between vaccination uptake rate and socio-economic factors. We found that the mean vaccine roll-out index is 0.016 (standard deviation 0.016), with a range between 0.0001 (Haiti) and 0.0829 (Mongolia). The top four factors associated with the vaccine roll-out index are the median per capita income, human development index, percentage of individuals who have used the internet in the last three months, and health expenditure per capita. The still-ongoing COVID-19 pandemic has shed light on the disparity in vaccine adoption across low- and high-income countries, which represents a global public health challenge. We must pave the way for universal access to vaccines and other approved treatments, regardless of demographic structures and underlying health conditions. Income disparity remains, instead, an important cause of vaccine inequity, which restricts the functioning of the global vaccine allocation framework and, thus, the ending of the pandemic. Stronger mechanisms are needed to foster countries’ political willingness to promote vaccine and drug access equity in a globalized society where future pandemics and other global health crises can be anticipated.

Explainable Machine Learning Approaches to Assess the COVID-19 Vaccination Uptake: Social, Political, and Economic Aspects

“…Another top feature that significantly predicts COVID-19 vaccination uptake is Gross Domestic Product (GDP). This finding is in line with [115][116][117]. The association between GDP and higher vaccination rate is, however, intuitive.…”

“…As Roghani and Panahi [116] have a notably higher GDP, this can contribute to the higher vaccination rate due to the fact that GDP, national strategy, and proper utilization of the resources of a country are likely to be highly associated. A study conducted by Kazemi et al [117] also found evidence of the association between median per capita income and overall vaccination adoption. The authors used the Random Forest algorithm for their analysis on a data set of 142 countries.…”

“…Countries with better public health infrastructures are resilient to tackle epidemic or pandemic. Few researchers [79][80][81][82][83]. included the HI variable to assess the vaccination coverage.…”

“…GDP, which is an indicative measure of the relative prosperity of a country, also explains why inequality in accessing the COVID-19 vaccine is an issue for developing and underdeveloped countries of the world. Kazemi et al [117] point out that the disparity in vaccine adoption is due to the fact that countries are different in terms of their income (low, medium, and high-income). Whereas developed countries succeeded in securing vaccines instantly when it was invented, many developing and underdeveloped countries had to deal with budget shortages in purchasing vaccines and providing required healthcare at the time of the pandemic.…”

COVID-19 vaccine adoption and hesitancy among older Veterans

“…their spouse. Accessing the internet has been well explored as a barrier to COVID-19 vaccination, [ 5 , 19 ] and future efforts will require healthcare systems to provide alternate access points for vaccine registration. While initially a limitation, the recent passage of the SAVE LIVES Act [ 20 ] now allows for vaccination of Veterans’ caregivers and family members and has tasked the VA with expanding eligibility from 9 million to more than 33 million individuals in the United States [ 21 ].…”