JMIR Form Res. 2022 Oct 29. doi: 10.2196/41914. Online ahead of print.
ABSTRACT
BACKGROUND: Despite continuing efforts to improve inclusion of underserved groups in clinical research, gaps in diversity remain. Participation of special populations is especially important when facing problems of unprecedented complexity such as COVID-19. A better understanding of factors associated with immune response in diverse populations would advance future preventive and curative approaches.
OBJECTIVE: The objective of this study was to investigate the factors potentially responsible for adverse events following the COVID-19 immunization. The population of the study included adults from rural areas, developing countries, and those with medically understudied conditions, across a broad age range.
METHODS: The study evolved from peer-support networks developed during the COVID-19 pandemic. Participants were recruited digitally through online neighborhood and health communities. Some of the participants volunteered as study investigators assisting with off-line recruitment and safety monitoring. Individuals who consented to participate were asked to share their vaccination experiences either using constantly-evolving online surveys or via one-to-one communication. Inferential statistics to estimate differences between study groups was performed using parametric and non-parametric tests.
RESULTS: Of 1430 participants who shared their vaccination experiences, 648 had outcome measures at their 1.5-year follow-up. Statistically significant differences were found between age groups, types of vaccine adverse events (VAEs), incidences of breakthrough infections and health conditions linked to the microbiome. Pairwise comparisons showed that VAEs interfering with daily activities were significantly higher in both younger (18-59) and older groups (80-100, P < .001) when compared to the 60-79 age bracket. Short term VAEs were associated with lower incidence of breakthrough COVID-19 relative to those who reported either minimal or long-term adverse events (P < .001). A genetic origin was suggested for some adverse reactions.
CONCLUSIONS: The findings of this study demonstrate that vaccine adverse reactions in the elderly are being overlooked and the incidence of VAEs impairing immunity may be higher than previously thought. Better preventive measures are needed for all those at risk for life-threatening and long-term adverse events of vaccination. Supportive community-based studies focusing on these populations could add important data to the body of knowledge. Further and more comprehensive studies should follow.
CLINICALTRIAL: ClinicalTrials.gov NCT04832932; https://clinicaltrials.gov/ct2/show/NCT04832932.
INTERNATIONAL REGISTERED REPORT: RR2-10.1101/2021.06.28.21256779.
PMID:36309347 | DOI:10.2196/41914
