Coronavirus Disease 2019 Messenger RNA Vaccine and Liver Transplant Recipients

TO THE EDITOR:

We would like to share ideas on the article “Antibody Response to Severe Acute Respiratory Disease Coronavirus 2 Messenger RNA Vaccines in Liver Transplant Recipients” by Strauss et al.^{( 1 )} In this article, the authors include this statement: “Because LT recipients often receive milder induction and maintenance immunosuppression, they may have a more robust humoral response.”^{( 1 )} At present, there are many reports on vaccination for transplant recipients and some reports on extraordinary vaccination regimens, such as multiple dose regimens.^{( 2 )} A consideration of the ethical issues regarding vaccination is very important.^{( 3 )} The present report is a good example of an ethical observational study on vaccination in transplant recipients. However, the method for measurement of antibody response should be discussed. Severe acute respiratory disease coronavirus 2 spike protein immunoassays might not reflect prevention. Hence, any conclusions regarding low immune response should be cautious. Also, the sensitivity of diagnostic tests should be discussed. Whether there is any interference effect from abnormal liver function (such as low protein and high bilirubin) is an interesting question that needs study.