(HealthDay News) — Solid organ transplant recipients (SOTRs) who have received 2 doses of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine have lower COVID-19 mortality rates than those who remain unvaccinated, but their risk for breakthrough infections is higher compared with the general population, according to 2 research letters published online in Transplantation.
Rommel Ravanan, PhD, from NHS Blood and Transplant in Bristol, England, and colleagues followed 48,213 solid organ and islet transplant recipients for SARS-CoV-2 vaccine uptake, testing positive for SARS-CoV-2, and death within 28 days of testing positive. As of July 9, 2021, 82% had received both vaccine doses, while 4% had received 1 dose and 14% remained unvaccinated or had contracted infection prior to vaccination, respectively. The researchers found that the mortality rate was 7.7 and ~12% for recipients of 2 doses versus unvaccinated patients and recipients of only 1 dose, respectively.
Caroline X. Qin, from the Johns Hopkins University School of Medicine in Baltimore, and colleagues estimated the rates of breakthrough infection after SARS-CoV-2 mRNA vaccination in SOTRs versus the general population. The researchers identified 151 breakthrough infections (0.83%) among 18,215 fully vaccinated SOTRs: 87 and 14 (0.48 and 0.077%) had associated hospitalization and death, respectively. Among SOTRs with breakthrough infection, mortality was 9.3%. Of 101 million fully vaccinated adults in the United States, there were reports of 10,262 breakthrough infections through April 30, 2021 (0.0102%): 995 and 160 (0.00099 and 0.00016%) had associated hospitalization and death, respectively.
“This emphasizes the clinical relevance of a growing literature describing decreased immunogenicity in this population, and highlights the critical need to better understand and improve vaccine response,” Qin and colleagues write.
Several authors from the Qin study disclosed financial ties to the pharmaceutical industry.