ABSTRACT
While mRNA vaccines are administrated worldwide in an effort to contain the COVID-19 pandemic, the heterogeneity of the humoral immune response they induce at the population scale remains unclear. Here, in a prospective, longitudinal, cohort-study, including 1245 hospital care workers and 146 nursing home residents scheduled for BNT162b2 vaccination, together covering adult ages from 19 to 99 years, we analyse seroconversion to SARS-CoV-2 spike protein and amount of spike-specific IgG, IgM and IgA before vaccination, and 3-5 weeks after each dose. We show that immunogenicity after a single vaccine dose is biased to IgG, heterogeneous and reduced with increasing age. The second vaccine dose normalizes IgG seroconversion in all age strata. These findings indicate two dose mRNA vaccines is required to reach population scale humoral immunity. The results advocate for the interval between the two doses not to be extended, and for serological monitoring of elderly and immunosuppressed vaccinees.
Subject(s)
Antibodies, Viral/immunology , BNT162 Vaccine/immunology , COVID-19/immunology , Immunization, Secondary , SARS-CoV-2/immunology , Adult , Age Factors , Aged , Aged, 80 and over , COVID-19/epidemiology , COVID-19/prevention & control , Female , Humans , Immunogenicity, Vaccine , Longitudinal Studies , Male , Middle Aged , Portugal/epidemiology , Prospective Studies , Seroconversion , Vaccination , Young AdultABSTRACT
Kidney transplant (KT) recipients are at an increased risk for severe COVID-19 because of their immunosuppressed state. A 42-year-old KT patient was diagnosed with COVID-19 three months after KT. Despite lymphopenia and several risk factors, he had a mild disease course. Nasopharyngeal real-time reverse transcriptase polymerase chain reaction for SARS-CoV-2 became negative 48 days after detection. SARS-CoV-2 IgG antibodies became negative after day 40. TTV DNA load increased with the onset COVID-19 and reduced after its resolution. This is the first report where TTV DNA load was measured during the course of COVID-19.
Subject(s)
Antibodies, Viral/immunology , COVID-19/immunology , DNA Virus Infections/immunology , DNA, Viral/metabolism , Immunocompromised Host , Immunoglobulin G/immunology , Kidney Transplantation , Torque teno virus/genetics , Adult , COVID-19/epidemiology , COVID-19 Nucleic Acid Testing , COVID-19 Serological Testing , Comorbidity , Diabetes Mellitus/epidemiology , Glucocorticoids/therapeutic use , Graft Rejection/prevention & control , Humans , Hypertension/epidemiology , Immunoglobulin M/immunology , Immunosuppressive Agents/adverse effects , Kinetics , Lymphopenia/immunology , Male , Mycophenolic Acid/adverse effects , Obesity/epidemiology , Prednisolone/therapeutic use , SARS-CoV-2/immunology , Severity of Illness Index , Tacrolimus/adverse effects , Viral LoadABSTRACT
Recent studies have shown that obesity is an independent predictor of lower N-terminal pro-BNP (NT-proBNP) levels and raised concerns about the validity of this biomarker in obese subjects. We evaluated the influence of obesity (body mass index>or=30 kg/m(2)) on the correlation between exercise capacity and serum NT-proBNP levels in 100 chronic heart failure (CHF) patients referred for cardiopulmonary exercise testing. Circulating NT-proBNP levels correlated well with lean body mass-adjusted peak oxygen consumption (VO(2)) in the entire cohort (R=-0.72, p<0.001) and in the obese (R=-0.71, p<0.001) and non-obese (R=-0.72, p<0.001) subgroups. There was no significant difference between the correlation coefficients of the two subgroups (p=0.934). In conclusion NT-proBNP levels predict exercise capacity in CHF patients irrespective of the presence of obesity.