Limitations
inflammation, uveitis
INFLAMMATION, DISEASE, UVEITIS, SECONDARY
This study has some limitations. First, interpretation of the outcomes was limited by the open nature of the trial, especially when interpreting results for a subjective outcome in the context of COVID-19 vaccination. Moreover, all symptoms were based on self-report, and we lacked data regarding clinical evaluation to confirm disease worsening. The possibility that the greater reporting bias in patients receiving COVID-19 vaccines may lead to the slightly higher incidence rather than the vaccine increasing inflammation cannot be ruled out. Second, our sample size fell short of expectations due to the lack of eligible unvaccinated patients in China, although this sample size was powered to detect the difference in the primary outcome. Third, a number of patients were not included in the month 3 in-person evaluable population. Nevertheless, this population was only related to several secondary outcomes, in which data showed materially small between-group differences in the point estimate. Moreover, results were similar after accounting for data missing with inverse probability weighting. Fourth, we could not precisely define which uveitis worsening was caused by COVID-19 vaccination. Instead, we only examined the excess risk of symptomatic worsening in the early vaccination group compared with the deferred one, with randomization leading to the balanced background risk between the 2 groups. To mitigate the interference of other factors unrelated to vaccination, we chose a 3-month observation period for vaccine uptake and uveitis worsening because a later onset of uveitis flare was less likely to be related to COVID-19 vaccination.