Authors' response.

We understand the concerns expressed by Drs Mungmunpuntipantip and Wiwanitkit regarding the efficacy and safety of messenger (m)RNA vaccines in patients with common variable immunodeficiency (CVID); however, we still strongly stick to the conclusions expressed in our report. With regard to efficacy, the aim of our study was to evaluate whether patients with CVID could generate neutralizing antibodies against severe acute respiratory syndrome coronavirus 2, and all but 1 actually did. Clearly, as already mentioned in the article, evaluation of the clinical significance of these antibodies (ie, protection against severe manifestations of coronavirus disease 2019 [COVID-19] and death) requires further studies. Nevertheless, it should not be overlooked that vaccine-induced cell-mediated immunity may as well contribute to vaccination efficacy. Therefore, prediction of vaccination efficacy should not be solely anticipated on the basis of antispike antibody titers. Long-term adverse effects of COVID-19 vaccination are unknown across all categories of subjects being immunized; conversely, short-term adverse effects are generally mild and easily managed. , Our patients with CVID have been followed up for more than 6 months since having completed the 2-dosage mRNA vaccine schedule, and none of them have developed or had flare-ups of autoimmune or other long-term inflammatory conditions; other studies have reported reassuring safety data as well. , , Furthermore, patients with rheumatologic diseases who have a myriad of autoimmune conditions have been thus far safely vaccinated with mRNA vaccines, with no apparent impact on disease activity and no further safety concerns in the short term. , Severe adverse events, albeit rare, may nonetheless occur after vaccination, regardless of preexisting medical conditions. In any case, caution should be exercised in interpreting flare-ups of autoimmune diseases in patients with rheumatologic diseases and, likewise, development of denovo autoimmune conditions in patients with CVID several months after vaccination, as they may be because of the natural history of the specific disease rather than to delayed, unwanted adverse effects of mRNA vaccination.

Patients with primary immunodeficiency, including CVID, are at increased risk from acute and long-term sequelae of COVID-19. At the moment, accumulating evidence points to a favorable benefit to risk ratio for COVID-19 vaccination even in such frail subjects as patients with CVID, who must thus be given the opportunity to be protected against the most dreaded manifestations of severe acute respiratory syndrome coronavirus 2 infection.