RESUMO
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19) and an ongoing global pandemic. Despite the development of vaccines, which protect healthy people from severe and life-threatening COVID-19, the immunological responses of people with secondary immunodeficiencies to SARS-CoV-2 mRNA vaccines are currently not well understood. Human Immunodeficiency Virus (HIV), causing acquired immunodeficiency syndrome (AIDS), targets CD4+ T helper (Th) cells that orchestrate the immune response. Anti-retroviral therapy suppresses HIV burden and restores Th cell numbers. Here, we investigated the humoral and cellular immune responses elicited by the BTN162b2 vaccine in a cohort of people living with HIV (PLWH), who receive anti-retroviral therapy. While antibody responses in PLWH increased progressively after the first and second vaccination compared to baseline, they were reduced compared to HIV negative study participants (controls). CD8+ T cells exhibited a general activated phenotype and increased effector and effector memory compartments. In contrast, CD4+ Th cell responses exhibited a vaccination-dependent increase and were comparable between PLWH and controls. In line with their reduced humoral response, the correlation between neutralizing antibodies and the CD4+ T cell response was decreased in PLWH compared to healthy controls. Interestingly, CD4+ T cell activation negatively correlated with the CD4 to CD8 ratio, indicating that low CD4 T cell numbers do not necessarily interfere with cellular immune responses. Taken together, our data demonstrate that COVID-19 mRNA vaccination in PLWH results in potent cellular immune responses, but the reduced antibody responses suggest that booster vaccination might be required for preventing disease.
RESUMO
BackgroundThe contribution of droplet-contaminated surfaces for virus transmission has been discussed controversially in the context of the current Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) pandemic. Importantly, the risk of fomite-based transmission has not been systematically addressed. MethodsWe initiated this single-center observational study to evaluate whether hospitalized COVID-19 patients can contaminate stainless steel carriers by coughing or intensive moistening with saliva and to assess the risk of SARS-CoV-2 transmission upon detection of viral loads and infectious virus in cell culture. Fifteen hospitalized patients with a high baseline viral load (CT value [≤] 25) shortly after admission were included. We documented clinical and laboratory parameters and used patient samples to perform virus culture, quantitative PCR and virus sequencing. ResultsNasopharyngeal and oropharyngeal swabs of all patients were positive for viral RNA on the day of the study. Infectious SARS-CoV-2 could be isolated from 6 patient swabs (46.2 %). While after coughing, no infectious virus could be recovered, intensive moistening with saliva resulted in successful viral recovery from steel carriers of 5 patients (38.5 %). ConclusionsTransmission of infectious SARS-CoV-2 via fomites is possible upon extensive moistening, but unlikely to occur in real-life scenarios and from droplet-contaminated fomites.
