Schrezenmeier and colleagues report a poor effect of a third dose of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination in kidney transplant recipients (KTR) who had no response to the two previous doses (December 2021 issue).1 At 27 days after the third dose, seroconversion was observed in only nine of the 25 (36%) KTR without a previous seroconversion. This low efficacy of booster doses in KTR emphasizes the need for alternative multidose vaccination strategies for transplant recipients and, more broadly, patients who are immunocompromised. Moreover, coronavirus disease 2019 vaccines are still scarce worldwide and a vast majority of the world’s population is still awaiting their first jab. The World Health Organization advises prioritizing global vaccination coverage, and preserving booster doses for the populations in greatest need.2 To address these two issues, we feel that intradermal administration should be considered in patients who are immunocompromised.3(preprint) Indeed, a recent report on 38 healthy adults provides preliminary evidence that intradermal injection of SARS-CoV-2 mRNA vaccines is as effective as intramuscular injection.3(preprint) Intradermal SARS-CoV-2 mRNA vaccination (n=24) resulted in equal antibody responses compared with intramuscular vaccination (n=14), using only one fifth to one tenth of the intramuscular dose. The efficacy of the intradermal dose is in line with previous studies on influenza vaccine responses in patients who are nonresponding after kidney transplant, showing significantly greater seroconversion rates and significantly higher peak antibody titers after intradermal booster vaccination compared with intramuscular administration.4 Therefore, intradermal SARS-CoV-2 vaccination has the potential to solve both the scarcity of vaccines at a global level, and to improve efficacy. Studies investigating the clinical efficacy of dose-sparing intradermal SARS-CoV-2 booster vaccines are urgently needed.
K. Wissing reports having an advisory or leadership role with Astellas and AstraZeneca. All remaining authors have nothing to disclose.
1. Schrezenmeier E, Rincon-Arevalo H, Stefanski AL, Potekhin A, Straub-Hohenbleicher H, Choi M, et al.: B and T cell responses after a third dose of SARS-CoV-2 Vaccine in kidney transplant recipients. J Am Soc Nephrol 32: 3027–3033, 2021
2. World Health Organization: Interim statement on COVID-19
vaccine booster doses. 2021. Available at: https://www.who.int/news/item/10-08-2021-interim-statement-on-covid-19-vaccine-booster-doses
. Accessed December 6, 2021
3. Roozen GVT, Prins MLM, van Binnendijk R, Hartog GD, Kuiper VP, Prins C, et al.: Tolerability, safety and immunogenicity of intradermal delivery of a fractional dose mRNA-1273 SARS-CoV-2 vaccine in healthy adults as a dose sparing strategy. medRxiv. 10.1101/2021.07.27.21261116 (Preprint posted July 27, 2021)
4. Morelon E, Pouteil Noble C, Daoud S, Cahen R, Goujon-Henry C, Weber F, et al.: Immunogenicity and safety of intradermal influenza vaccination in renal transplant patients who were non-responders to conventional influenza vaccination. Vaccine 28: 6885–6890, 2010