Humoral and cellular immune response after severe acute respiratory syndrome coronavirus 2 messenger ribonucleic acid vaccination in heart transplant recipients: An observational study in France

Abstract

IntroductionHeart transplant (HT) recipients have a high risk of developing severe COVID-19. Immunoglobulin G antibodies are considered to provide protective immunity and T-cell activity is thought to confer protection from severe disease. However, data on T-cell response to mRNA vaccination in a context of HT remains limited.MethodsIn 96 HT patients, a IFN-γ release assay and an anti-Spike antibody test were used to evaluate the ability of SARS-CoV-2 mRNA vaccines to generate cellular and humoral immune response. Blood samples were collected few weeks to 7 months after vaccination. Multiple fractional polynomial and LASSO regression models were used to define predictors of T-cell response.ResultsThree to five months after vaccination, three doses of vaccine induced a positive SARS-CoV-2 T-cell response in 47% of recipients and a positive humoral response in 83% of recipients, 11.1% of patients remained negative for both T and B cell responses. Three doses were necessary to reach high IgG response levels (>590 BAU/mL), which were obtained in a third of patients. Immunity was greatly amplified in the group who had three vaccine doses plus COVID-19 infection.ConclusionOur study revealed that T and B immunity decreases over time, leading us to suggest the interest of a booster vaccination at 5 months after the third dose. Moreover, a close follow-up of immune response following vaccination is needed to ensure ongoing immune protection. We also found that significant predictors of higher cellular response were infection and active smoking, regardless of immunosuppressive treatment with mycophenolate mofetil (MMF).

Understanding Concerns about COVID-19 and Vaccination: Perspectives from Kidney Transplant Recipients

“…This status has led to questions about transplant patients’ abilities to fight COVID-19 infection, as well as about their abilities to mount immune responses from vaccination [ 24 ]. While growing research is increasing our knowledge about COVID-19 infection and the COVID-19 vaccine responses in immunocompromised individuals [ 25 , 26 ], less attention has been paid to the experiences of transplant patients during the pandemic as they navigate the risks of this public health crisis [ 16 ]. Our study served to fill this knowledge gap by exploring the perspectives of KTRs, particularly related to KTRs’ perspectives about COVID-19 vaccination and the differences in pandemic experiences between those who were vaccinated or unvaccinated.…”

The safety and immunogenicity of a two-dose schedule of CoronaVac, and the immune persistence of vaccination for six months, in people living with HIV: A multicenter prospective cohort study

“…Besides, this study also measured humoral responses to wild-type SARS-CoV-2 and evaluated the immune durability during the six months postvaccination. Considering that S-antigen specific gamma-interferon (IFN-γ) was induced by T-cell immunity, which was deemed to be associated with protection against SARS-CoV-2 and severe disease according to WHO guidelines and existing studies ( 27 ), S-antigen specific IFN-γ was also assessed in this study. The factors correlated with nAbs and S-IgG were further investigated.…”