Global report on COVID-19 vaccination and reasons not to vaccinate among adults with intellectual disabilities: Results from secondary analyses of Special Olympics’ program planning

The COVID-19 pandemic has disproportionately affected people with intellectual disabilities worldwide. The objective of this study was to identify global rates of COVID-19 vaccination and reasons not to vaccinate among adults with intellectual disabilities (ID) associated with country economic income levels. The Special Olympics COVID-19 online survey was administered in January-February 2022 to adults with ID from 138 countries. Descriptive analyses of survey responses include 95% margins of error. Logistic regression and Pearson Chi-squared tests were calculated to assess associations with predictive variables for vaccination using R 4.1.2 software. Participants (n = 3560) represented 18 low (n = 410), 35 lower-middle (n = 1182), 41 upper-middle (n = 837), and 44 high (n = 1131) income countries. Globally, 76% (74.8–77.6%) received a COVID-19 vaccination while 49.5% (47.9–51.2%) received a COVID-19 booster. Upper-middle (93% (91.2–94.7%)) and high-income country (94% (92.1–95.0%)) participants had the highest rates of vaccination while low-income countries had the lowest rates (38% (33.3–42.7%)). In multivariate regression models, country economic income level (OR = 3.12, 95% CI [2.81, 3.48]), age (OR = 1.04, 95% CI [1.03, 1.05]), and living with family (OR = 0.70, 95% CI [0.53, 0.92]) were associated with vaccination. Among LLMICs, the major reason for not vaccinating was lack of access (41.2% (29.5–52.9%)). Globally, concerns about side effects (42%, (36.5–48.1%)) and parent/guardian not wanting the adult with ID to vaccinate (32% (26.1–37.0%)) were the most common reasons for not vaccinating. Adults with ID from low and low-middle income countries reported fewer COVID-19 vaccinations, suggesting reduced access and availability of resources in these countries. Globally, COVID-19 vaccination levels among adults with ID were higher than the general population. Interventions should address the increased risk of infection for those in congregate living situations and family caregiver apprehension to vaccinate this high-risk population.


Abstract
The COVID-19 pandemic has disproportionately affected people with intellectual disabilities worldwide. The objective of this study was to identify global rates of COVID-19 vaccination and reasons not to vaccinate among adults with intellectual disabilities (ID) associated with country economic income levels. The Special Olympics COVID-19 online survey was administered in January-February 2022 to adults with ID from 138 countries. Descriptive analyses of survey responses include 95% margins of error. Logistic regression and Pearson Chi-squared tests were calculated to assess associations with predictive variables for vaccination using R 4.1.2 software. Participants (n = 3560) represented 18 low (n = 410), 35 lower-middle (n = 1182), 41 upper-middle (n = 837), and 44 high (n = 1131) income countries. Globally, 76% (74. .6%) received a COVID-19 vaccination while 49.5% (47.9-51.2%) received a COVID-19 booster. Upper-middle (93% (91.2-94.7%)) and high-income country (94% (92.1-95.0%)) participants had the highest rates of vaccination while low-income countries had the lowest rates (38% (33.3-42.7%)). In multivariate regression models, country economic income level (OR = 3.12, 95% CI [2.81, 3.48]), age (OR = 1.04, 95% CI [1.03, 1.05]), and living with family (OR = 0.70, 95% CI [0.53, 0.92]) were associated with vaccination. Among LLMICs, the major reason for not vaccinating was lack of access (41.2% (29.5-52.9%)). Globally, concerns about side effects (42%, (36.5-48.1%)) and parent/guardian not wanting the adult with ID to vaccinate (32% (26.1-37.0%)) were the most common reasons for not vaccinating. Adults with ID from low and low-middle income countries reported fewer COVID-19 vaccinations, suggesting reduced access and availability of resources in these countries. Globally, COVID-19 vaccination levels among adults with ID were higher than the general population. Interventions should address the increased risk of infection for those in congregate living situations and family caregiver apprehension to vaccinate this high-risk population.

Introduction
The COVID-19 pandemic has impacted people with intellectual disabilities (ID) across the world. Intellectual disability originates during early human development and is defined by significant limitations in intellectual functioning and adaptive functioning in conceptual, social, and practical domains [1]. People with ID have a higher risk of contracting COVID-19, have poorer health outcomes than the general public, and are on average six times more likely than the general population to die from COVID-19 following hospital admission [2][3][4][5]. In the United States, COVID-19 was the leading cause of death among those with intellectual and developmental disabilities in 2020 [6]. People with specific diagnoses associated with ID are particularly prone to increased risk of hospitalization and death, including those with Down syndrome, Autism, cerebral palsy, and fragile X syndrome [7][8][9][10][11]. There are numerous reasons why people with ID are particularly vulnerable to experiencing severe COVID-19 illness and death [12]. Specifically, people with ID may have difficulty accessing care as readily as the general population [13,14]. Some live in congregate settings in which COVID-19 has spread more easily [15,16]. People with ID are also much more likely to have preexisting conditions that raise the likelihood of experiencing severe outcomes following COVID-19 infection, such as hereditary and cardiac conditions, inborn errors of metabolism, respiratory conditions, and obesity [12]. Finally, people with ID may have more challenges with risk mitigation measures, such as masking and distancing [17].
The increased risk of COVID-19 and its consequences make people with ID a particularly important group for vaccination. However, global use of vaccines during the COVID-19 pandemic has differed based on regional public health efforts, allocation of vaccines, type of vaccine, and vaccine acceptance. Among the general population, COVID-19 infection, use of prevention strategies, and vaccination varied by country economic levels [18][19][20]. In lowincome nations, challenges in COVID-19 testing and vaccine availability, distribution, and administration are barriers to controlling the spread of the epidemic [21].
Based on a recent systematic review, the global acceptance and uptake rate of COVID-19 vaccination is 67.8% in the general population [22]. Global COVID-19 vaccine uptake rates are less known among those with ID, resulting in unknown levels of COVID-19 protection in this vulnerable population. Enhancing equity of persons with ID in the tracking of vaccine uptake and pandemic-related health outcomes is paramount [23]. This can be achieved through partnerships with the disability community and disability organizations.
Special Olympics is an international non-profit organization that provides sports competition and promotes health, education and leadership opportunities to over five million people with ID in 200 countries [24]. Early in the COVID-19 pandemic, Special Olympics recognized the potential increased risk for people with ID and created resources to help participants stay healthy and maintain connections among the Special Olympics community. Special Olympics compiled and disseminated accessible resources to program participants and the larger community on topics such as healthy behaviors during COVID-19 (e.g., handwashing, wearing a face mask), resources designed to help participants maintain fitness levels at home, and other virtual activities to maintain social connections with participants, coaches, and friends [25]. These prevention activities were largely carried out at the local level across the world and based on each country's COVID-19 protocols and vaccination roll out. COVID-19 vaccination recommendations were distributed to the heads of each region to distribute to their respective programs. This included a vaccination requirement communicated on January 26, 2022 for international Special Olympics competitions.
Special Olympics' presence across countries with varying economic levels drove the need to better understand global characteristics of the COVID-19 pandemic among adults with ID.
The objective of this study was to investigate global rates of COVID-19 vaccination and reasons not to vaccinate among adults with ID who participate in Special Olympics relative to World Bank country economic income levels.

Ethics statement
This investigation was reviewed by the Oregon State University Institutional Review Board application HE-2022-59 on November 10, 2022. The IRB determined that it does not meet the definition of human subjects research under the regulations set forth by the Department of Health and Human Services 45 CFR 46. Formal consent was not obtained as the survey was part of internal program planning. This information was critical to guide Special Olympics in policy decisions regarding return to in-person competitions during the pandemic. Secondary analyses on anonymous program planning data were conducted to describe the global distribution of COVID-19 vaccination and reasons not to vaccinate among adults with intellectual disabilities.
The Special Olympics COVID-19 survey was conducted with an online sample of adults with intellectual disabilities 18 years or older who participated in Special Olympics sport, health, schools/education, or leadership programming in 138 countries. Special Olympics Programs distributed the survey through their networks of athletes, families, and coaches. Programs used athlete and family registration listservs from sport and health programming to disseminate the survey. After survey dissemination, there was no connection to personally identifiable information as responses were anonymous. The survey was developed via the Qualtrics platform (Qualtrics, Provo, UT) and remained open for responses from January through February 2022. The survey was originally created in English and translated by Special Olympics regional staff for the following languages: Arabic, Chinese (simplified), French, German, Portuguese, Russian, and Spanish. Questions were self-reported by adults with ID, though proxy responses from family members/caregivers or staff/volunteers were also accepted. The voluntary survey included questions regarding demographics (i.e., sex, age, country, living situation, and who completed the survey), disability characteristics (i.e., Autism, Down syndrome, cerebral palsy and fragile x), COVID-19 vaccination, and a multiselect question of reasons for non-vaccination. COVID-19 vaccination was measured by asking participants if they received a COVID-19 vaccine. Those who had not received a COVID-19 vaccination and did not plan to receive one were asked what the reasons were for their decision. Since the survey was intended for administrative use, data were collected without personally identifiable information (e.g., name, date of birth).
Data across 138 countries were categorized by the World Bank economic income levels of low-income country (LIC), lower-middle income country (LMIC), upper-middle income country (UMIC), and high-income country (HIC) for primary analyses [26]. Analyses were conducted to examine COVID-19 vaccination by diagnosis. Descriptive statistics were calculated as count and proportion of responses. For all proportions, 95% margins of error were calculated [27]. Logistic regression was performed to highlight the associations between demographic variables and country economic income level with COVID-19 vaccination rates. We chose a priori to include potentially confounding demographic variables in the regression model while adjusting for other interpersonal (e.g., living situation) and macro (e.g., country economic level) variables. Pearson Chi-squared tests estimated differences in vaccine acceptance across low and lower-middle income countries (LLMIC) compared to upper-middle and high-income countries (UMHIC). Analyses were performed using R version 4.1.2 (R Foundation for Statistical Computing; Vienna, Austria). Data used in this analysis can be found in S1 Table.

Discussion
This study identified an association between country economic level and COVID-19 vaccination and reasons for not accepting vaccine among adults with ID. Participants from LLMICs reported fewer COVID-19 vaccinations than those from UMHICs and a higher willingness to vaccinate among those who are not yet vaccinated. Apart from the lack of vaccine access in LICs, the most common reasons for not vaccinating, across country income level were concerns regarding vaccine side effects and parent/guardians' apprehension to vaccinate this high-risk population (Table 4).
Over 75% of adults with ID in the current study were vaccinated against COVID-19 compared to 60% of the global population during the same time period [28]. The relatively higher rates of COVID-19 vaccination among adults with ID in UMHICs suggest evidence of effective public health polices, favorable vaccine acceptance, and public health messaging from Special Olympics. At the time of this study, governments across the world implemented universal policies for vaccine delivery for vulnerable populations [29]. The high rates of vaccination found in our study are compatible with favorable vaccine uptake among those with ID reported by  Despite overall high rates of vaccination among adults with ID, there were dramatic differences in vaccination across country economic levels. Lower overall vaccination in LICs compared to HICs is consistent with global COVID-19 vaccine dosages administered. As of January 2, 2022, Our World in Data reported higher levels of COVID-19 vaccine doses administered among UMICs (169.73 per 100 people) and HICs (166.18) compared to LMICs (84.12) and LICs (10.67) [32]. Such findings suggest a lack of resources and infrastructure to vaccinate large populations among many LLMICs [33]. This is supported by the plurality of LIC respondents stating a lack of access to COVID-19 vaccines as a reason for not vaccinating (Table 4). Also, as shown by the rates of under-vaccinated children in LLMICs, vaccine infrastructure may be inadequate for large scale pandemic response [33]. Vaccine access may be further exacerbated by a lack of transportation. Transportation may be a barrier for those who depend on others or need accessible transportation to a vaccination site [34]. Despite LICs having vaccines at the time of study, those in remote or rural communities may lack access to vaccinations sites. This would be consistent with our current findings where LICs reported higher proportion of transportation barriers potentially linking their access to lack of vaccine availability in their geographical area. Policies in LICs should consider accessible transit options to vaccination sites or mobile vaccination clinics in remote or rural areas. Among those not vaccinated, more adults with ID from LLMICs planned to receive the COVID-19 vaccine compared to UMHICs. Among the unvaccinated population overall, LLMICs generally show higher willingness to accept vaccines than higher income countries [35][36][37]. However, a recent study indicates growing pockets of vaccine hesitancy [38]. As vaccines become more accessible to LLMIC, providers should focus communication on building trust, working with trusted stakeholders (e.g., community health workers), and engaging in broad community outreach to reduce vaccine hesitancy and rebuild confidence in vaccination programs for vulnerable and underserved communities [37].

Diagnosis
Our findings document the most common reasons that adults with ID did not vaccinate across multiple levels of the socioecological framework [38]. Vaccination campaigns that target multiple levels of the socioecological model, focus on dialogue-based communication, and include community stakeholders yield better outcomes [39]. At the individual level, concerns about vaccine side-effects and safety were top reasons for not receiving a COVID-19 vaccine across country economic levels. However, higher rates of respondents in UMHICs expressed concerns about side effects and safety than LLMICs. Those in UMHICs also expressed skepticism that the vaccine would work, which is consistent with prior research [40]. At the interpersonal level of influence, the decision to vaccinate was significantly influenced by caregivers. Globally, parent/guardian restriction for vaccination was a primary reason those with ID were not vaccinating for COVID-19. These results complement Iadorola et al.'s (2022) study where those making decisions on behalf of a person with ID had more vaccine hesitancy than those with ID themselves [31]. These collective findings highlight the need to provide vaccine outreach and education tailored to caregivers' apprehension towards COVID-19 vaccination. Providing clear information about vaccine risks and incorporating trusted sources of information, including health care providers, may improve vaccine uptake worldwide for those with ID. We identified variations in diagnoses of ID across economic country levels. LICs and LMICs had higher proportions of respondents with cerebral palsy. Preventable risk factors (e.g., infections during infancy and early childhood) may be the cause for increased cerebral palsy diagnosis in these countries [41,42]. Variations in conditions across economic country level could interact with caregiver apprehension and access, though these were beyond the scope of this study. This study has several limitations. Findings are from a sample of adults with ID who participate in Special Olympics programming and may not be generalizable to the broader population of persons with ID. Special Olympics recommendations and policy on vaccination may have influenced vaccine uptake. The study population includes 181 countries and states with Special Olympics affiliates but is not representative of all countries within economic levels. Each of the 181 countries and states relied on their networks of coaches, volunteers, and staff to distribute the survey, resulting in a convenience sampling approach. Because the survey was web-based, participants without internet access could not be included and likely contributed to overestimates of vaccination. All data was self-reported, and the vaccination type and dosage were not available for analysis. Nonetheless, this is the largest study of COVID-19 vaccination among people with ID to date that included representation from three-fourths of the world's countries.
Future work will be dedicated to more trans-national studies regarding the health and wellbeing of the Special Olympics community. As part of this endeavor, Special Olympics aims to improve data collection methods by building a global network of excellence with academic partners to collect more variables that are not limited to self-or proxy-report. In addition, Special Olympics will perform prospective longitudinal studies to better assess the impact of health interventions on the ID community. Special Olympics mission is to contribute to the scientific literature and provide health care providers and governments with actionable insights to better protect and promote the health of individuals with ID.

Conclusion
This global study identified a significant association of country economic level on rates of COVID-19 vaccination and reasons for not accepting vaccine among adults with ID. Adults with ID from low and low-middle income countries reported fewer COVID-19 vaccinations and indicated reduced access as a primary reason for non-vaccination. Globally, COVID-19 vaccination levels among adults with ID were higher than the general population. Consistent with the general population, concerns about side effects play an important role in non-vaccination. Findings support the need to implement public health interventions that address family caregivers' apprehension to vaccinate this high-risk population, a unique reason for vaccination refusal among those with ID globally.
Supporting information S1