USPSTF Recommendations on Vitamin and Mineral Supplements for Primary Prevention of Cardiovascular Disease and Cancer

Abstract

In Reply We appreciate the comments by Dr Jiang and colleagues regarding our recent Research Letter. 1 In our cohort, 5 of 79 patients (6.3%) during the Delta wave and 5 of 33 patients (15.1%) during the Omicron wave received a second dose of the SARS-CoV-2 vaccine at least 2 weeks prior to hospital admission; none of the vaccinated patients were admitted to intensive care units or required treatment with vasopressors. 1 The incidence rate of MIS-C during the Omicron wave was lower than during both the Delta and Alpha waves. 1 Jiang and colleagues state that receipt of 2 doses of SARS-CoV-2 vaccine "was associated with a lower incidence and more favorable outcomes of MIS-C." However, given that our study was retrospective and included a low number of vaccinated patients, causation cannot be inferred between vaccination status and a lower incidence or favorable outcomes of MIS-C. Other possible explanations for these findings include biological and epidemiological characteristics of the Omicron variant, previous infection with SARS-CoV-2, and improved treatment protocols over time. We cannot address any questions regarding vaccine-related MIS-C because patients in our study 1 did not undergo antinucleocapsid or antispike antibody testing.Several recent studies support vaccine effectiveness against MIS-C. Holm et al 2 and Nygaard et al 3 reported that the risk of MIS-C during the Omicron wave in Denmark was significantly lower in vaccinated compared with unvaccinated children and adolescents. A study from France by Levy et al 4 found that most adolescents who developed MIS-C were eligible for a SARS-CoV-2 vaccine but had not been vaccinated, suggesting that SARS-CoV-2 vaccination was associated with a lower incidence of MIS-C in adolescents. Zambrano et al 5 reported that during the Delta wave, the estimated effectiveness of the SARS-CoV-2 vaccine against MIS-C was 91% and all critically ill patients with MIS-C who required life support (ie, invasive mechanical ventilation, vasoactive infusions, or extracorporeal membrane oxygenation) were unvaccinated. In addition, a multicenter case-control study found that vaccination with 2 doses of SARS-CoV-2 vaccine was associated with reduced likelihood of MIS-C. 6 In light of the existing studies and a number of other published reports, we believe that there is enough evidence to conclude that SARS-CoV-2 vaccination can reduce the incidence and severity of MIS-C.