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1.
J Heart Lung Transplant ; 41(6): 765-772, 2022 06.
Article in English | MEDLINE | ID: covidwho-1739750

ABSTRACT

BACKGROUND: Serological responses to COVID-19 vaccination are diminished in recipients of solid organ transplants, especially in lung transplant recipients (LTR), probably as result of immunosuppressive treatment. There is currently no marker of immunosuppression that can be used to predict the COVID-19 vaccination response. Here, we study whether torque tenovirus (TTV), a highly prevalent virus can be used as an indicator of immunosuppression. METHODS: The humoral response to the mRNA 1273 vaccine was assessed in 103 LTR, who received a transplant between 4 and 237 months prior to vaccination, by measuring Spike (S)-specific IgG levels at baseline, 28 days after first, and 28 days after the second vaccination. TTV loads were determined by RT-PCR and Pearson's correlation coefficient was calculated to correlate serological responses to TTV load. RESULTS: Humoral responses to COVID-19 vaccination were observed in 41 of 103 (40%) LTR at 28 days after the second vaccination. Sixty-two of 103 (60%) were non-responders. Lower TTV loads at baseline (significantly) correlated with higher S-specific antibodies and a higher percentage of responders. Lower TTV loads also strongly correlated with longer time since transplantation, indicating that participants with lower TTV loads were longer after transplantation. CONCLUSIONS: This study shows a better humoral response to the SARS-CoV-2 vaccine in subjects with a lower TTV load pre-vaccination. In addition, TTV load correlates with the time after transplantation. Further studies on the use of TTV load in vaccination efficacy studies in immunocompromised cohorts should provide leads for the potential use of this marker for optimizing vaccination response.


Subject(s)
COVID-19 , Torque teno virus , 2019-nCoV Vaccine mRNA-1273 , COVID-19/prevention & control , COVID-19 Vaccines , Humans , Lung , SARS-CoV-2 , Torque , Torque teno virus/genetics , Transplant Recipients , Vaccination
2.
Sci Immunol ; 7(69): eabo2202, 2022 03 25.
Article in English | MEDLINE | ID: covidwho-1673343

ABSTRACT

The severe acute respiratory distress syndrome coronavirus 2 (SARS-CoV-2) Omicron variant is spreading rapidly, even in vaccinated individuals, raising concerns about immune escape. Here, we studied neutralizing antibodies and T cell responses targeting SARS-CoV-2 D614G [wild type (WT)] and the Beta, Delta, and Omicron variants of concern in a cohort of 60 health care workers after immunization with ChAdOx-1 S, Ad26.COV2.S, mRNA-1273, or BNT162b2. High binding antibody levels against WT SARS-CoV-2 spike (S) were detected 28 days after vaccination with both mRNA vaccines (mRNA-1273 or BNT162b2), which substantially decreased after 6 months. In contrast, antibody levels were lower after Ad26.COV2.S vaccination but did not wane. Neutralization assays showed consistent cross-neutralization of the Beta and Delta variants, but neutralization of Omicron was significantly lower or absent. BNT162b2 booster vaccination after either two mRNA-1273 immunizations or Ad26.COV2 priming partially restored neutralization of the Omicron variant, but responses were still up to 17-fold decreased compared with WT. SARS-CoV-2-specific T cells were detected up to 6 months after all vaccination regimens, with more consistent detection of specific CD4+ than CD8+ T cells. No significant differences were detected between WT- and variant-specific CD4+ or CD8+ T cell responses, including Omicron, indicating minimal escape at the T cell level. This study shows that vaccinated individuals retain T cell immunity to the SARS-CoV-2 Omicron variant, potentially balancing the lack of neutralizing antibodies in preventing or limiting severe COVID-19. Booster vaccinations are needed to further restore Omicron cross-neutralization by antibodies.


Subject(s)
COVID-19 , SARS-CoV-2 , CD8-Positive T-Lymphocytes , COVID-19/prevention & control , COVID-19 Vaccines , Humans
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