Longitudinal humoral and cell-mediated immune responses in a population-based cohort in Zurich, Switzerland between March and June 2022 - evidence for protection against Omicron SARS-CoV-2 infection by neutralizing antibodies and spike-specific T-cell responses.

OBJECTIVES: The correlate(s) of protection against SARS-CoV-2 remain incompletely defined. Additional information regarding the combinations of antibody and T cell-mediated immunity which can protect against (re)infection is needed. METHODS: We conducted a population-based, longitudinal cohort study including 1044 individuals of varying SARS-CoV-2 vaccination and infection statuses. We assessed spike (S)- and nucleocapsid (N)-immunoglobulin(Ig)G and wildtype, Delta, and Omicron-neutralizing antibody (N-Ab) activity. In a subset of 328 individuals, we evaluated S, membrane (M), and N-specific T cells. Three months later, we reassessed Ab (n = 964) and T cell (n = 141) responses and evaluated factors associated with protection from (re)infection. RESULTS: At the study start, >98% of participants were S-IgG seropositive. N-IgG and M/N-T-cell responses increased over time, indicating viral (re)exposure, despite existing S-IgG. Compared to N-IgG, M/N-T cells were a more sensitive measure of viral exposure. High N-IgG titers, Omicron-N-Ab activity, and S-specific-T-cell responses were all associated with a reduced likelihood of (re)infection over time. CONCLUSION: Population-level SARS-CoV-2 immunity is S-IgG-dominated, but heterogeneous. M/N-T-cell responses can distinguish previous infection from vaccination, and monitoring a combination of N-IgG, Omicron-N-Ab, and S-T-cell responses may help estimate protection against SARS-CoV-2 (re)infection.

Approach for tuberculosis-associated immune reconstitution inflammatory syndrome in an HIV-negative patient.

A male refugee from the Middle East was diagnosed with pulmonary tuberculosis and Pott's disease with paravertebral abscess. After starting the standard regimen, the sputum culture converted to negative and the patient's general condition improved. Six weeks later, the patient presented with clinical worsening of known symptoms, new appearance of focal neurological deficits and progress of radiological features showing progression of the paravertebral abscess. Immune reconstitution inflammatory syndrome with Mycobacterium tuberculosis (TB-IRIS) was presumed, and treatment with high-dose steroids was started. Due to recurrent relapses while tapering, corticosteroids had to be given over a prolonged period. After treatment completion, the patient was in a good general condition, abscesses had decreased and neurological deficits were in complete remission. This case presents the rare manifestation of TB-IRIS in HIV-negative patients and its management in a high-income country.

Prosthetic valve endocarditis caused by Propionibacterium species successfully treated with coadministered rifampin: report of two cases.

We describe two cases of prosthetic valve endocarditis caused by Propionibacterium spp. successfully treated with a combination of rifampin and intravenous penicillin. Rifampin was chosen due to its promising activity against planktonic and biofilm Propionibacterium, its favourable minimal inhibitory concentrations, its excellent oral bioavailability and tissue penetration.