Efficacy and safety of mRNA COVID19 vaccines in high-risk veterans with cancer in rural Arkansas-Louisiana-Texas (ArkLATX): A patient-reported outcome study

ABSTRACT

Introduction: The COVID-19 pandemic continues to be a major socioeconomic disruptor worldwide. The intervention that has a far-reaching impact is a global vaccination campaign with the currently available and highly effective COVID-19 vaccines. Unfortunately, cancer patients are at a higher risk of contracting COVID-19 infection. Furthermore, they tend to experience a higher rate of morbidity and mortality than the general population. Therefore, we conducted this study to explore the efficacy of mRNA COVID-19 vaccines in a cohort of rural veterans with cancer in the ArkLATX. Methods: A cohort of 361 consecutive veterans across 5 Hematology-Oncology clinics were included in this study. An in-person survey was conducted asking the veterans whether they received the COVID-19 vaccine;if so, whether they had any reactions to it;whether they had any COVID-19 infections;and if they were vaccinated whether the infection was pre- or post-vaccination. They were also asked to determine the severity of their infection and their reactions to the vaccine when applicable. Age, sex, and race were captured for each participant. Descriptive statistics were calculated, and X2 and logistic regression were carried out to determine the impact of factors on the outcome and the significance of differences found between the studied subgroups. Results: The cohort consisted of 361 veterans, 303 vaccinated and 58 unvaccinated. The mean ages were 69 and 65 years, respectively. Among the vaccinated, 30% experienced vaccine adverse events, but only 2% reported it as severe. While there were more whites in the unvaccinated, there was no difference by sex. Only 2% of the vaccinated reported post-vaccine COVID19 infections versus 22% of the unvaccinated. One and 2 patients reported severe COVID19 infection in the vaccinated and unvaccinated subgroups, respectively. There was one patient who had a severe COVID19 infection before and after. The absolute and relative risk reduction for COVID19 vaccines were 20% and 91%, respectively. The number of patients needed to vaccinate to prevent one adverse outcome was 5. Conclusions: The current mRNA vaccines showed 91% efficacy at preventing COVID-19 infections in this high-risk rural veteran patient population with cancer. Aside from primarily mild transient local and systemic reactions, no safety concerns were identified by our patients. This real-life patient-reported outcome study confirms the efficacy and safety of COVID19 vaccines found in the general population.