Safety and Tolerability of mRNA COVID-19 Vaccines in Kidney Transplant Recipients

BACKGROUND: COVID-19 mRNA vaccines have demonstrated excellent short-term safety in phase 3 trials. However, no kidney transplant recipients (KTR) were included. The aim of the study was to assess the safety and tolerability of COVID-19 mRNA vaccines in KTR. MATERIALS AND METHODS: A longitudinal controlled study was conducted in 300 KTR and 143 control patients (CRL) without chronic kidney disease who had received 2-dose vaccinations with the mRNA vaccine. Solicited local and systemic reactogenicity and unsolicited adverse events were assessed with a standardized questionnaire. The toxicity grading scales were derived from the FDA guidelines. RESULTS: KTR (62.7% men) with a median (interquartile range) age of 53 (41-63) and transplant vintage of 7.25 (3-13) years did not differ with respect to age and sex distribution from CRL. One hundred percent CRL and 83.3% KTR were vaccinated with BNT162b2 (BionTech/Pfizer); 16.7% KTR received mRNA-1273 (Moderna) vaccine. Any local reactions were present in 84.7% (first dose) and 65.3% (second dose) KTR vs 67.1% and 60.1% CRL within 7 days after the vaccination. Any systemic reactions were reported by 26.7% (first dose) and 20.9% (second dose) KTR vs 24.7 and 35.7% CRL. The most common systemic reactions in KTR were fatigue, headache and myalgia. No serious adverse events were observed. Many systemic reactions were observed less frequently in KTR than CRL. Younger KTR (<54 years) reported any local and any systemic reactions significantly more frequently than older patients. CONCLUSION: mRNA COVID-19 vaccines are safe and well-tolerated by KTR. The results may resolve patients' doubts and reduce their vaccine hesitancy.