Assessment of immune responses to a Comirnaty® booster following CoronaVac® vaccination in healthcare workers.

BACKGROUND: The immunological response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and immunisation is variable. OBJECTIVES: To describe the humoral immune response by correlating IgA and IgG antibodies with NAbs titration following CoronaVac® immunisation and an mRNA (Comirnaty®) booster among healthcare workers (HCWs) and to compare the cytokine and interleukin profiles between HCWs vaccinated with CoronaVac and coronavirus disease 2019 (COVID-19) infected patients. METHODS: Samples from 133 HCWs collected at 20 (T1) and 90 (T2) days after CoronaVac immunisation and 15 (T3) days after a booster dose with the Comirnaty vaccine were analysed for IgA and IgG EIA and neutralisation assay. Cytokine levels from vaccinated individuals at T1 day and COVID-19 patients were compared. FINDINGS: Neutralising antibodies (NAbs) were observed in 81.7% of participants at T1, but only 49.2% maintained detectable NAbs after 90 days. The booster dose increased NAbs response in all participants. The cytokines with the highest levels post-vaccination were IL-6 and MCP-1. The MCP-1, IL-18, and IFN- γ levels were higher in COVID-19 patients than in vaccinated HCWs, while IL-22 levels increased in the vaccinated HCWs group. MAIN CONCLUSIONS: The neutralisation titres in the T2 samples decreased, and antibody levels detected at T2 showed a more significant reduction than the neutralisation. The higher IL-22 expression in immunised individuals compared to those with COVID-19 suggests that IL-22 may be beneficial in protecting against severe disease.

IgA antibody dynamics in healthcare workers after CoronaVac® vaccination and heterologous Comirnaty® booster dose.

BACKGROUND: This study is aimed at calculating the IgA antibody dynamic range in healthcare workers (HCWs) after immunization with CoronaVac® and Comirnaty® booster dose. METHODS: A total of 118 HCW serum samples from Southern Brazil were collected the day before the first vaccine dose (day 0) and + 20, + 40, + 110, + 200 days following the vaccine's first dose, and + 15 days after a Comirnaty® booster dose. Immunoglobulin A (IgA) was quantified using immunoassays for anti-S1 (spike) protein antibodies (Euroimmun, Lübeck, Germany). RESULTS: Seroconversion for the S1 protein occurred in 75 (63.56%) and 115 (97.47%) HCWs by day + 40 and day + 15 after the booster dose, respectively. There was an absence of IgA antibodies after the booster dose in two (1.69%) HCWs undergoing biannual rituximab administration and one (0.85%) HCW for no apparent reason. CONCLUSION: Complete vaccination showed a significant IgA antibody production response, and the booster dose considerably increased this response.

HIV, syphilis, hepatitis B and C in key populations: results of a 10-year cross-sectional study, Southern Brazil.

OBJECTIVE: Although the development of prevention and treatment strategies for sexually transmitted infections in key groups has improved over the years, they still remain a challenge for health systems worldwide. In this context, the objective of this study is to assess the seroprevalence in the tested population, with an emphasis on key populations, aiming at identifying the participants' profile and consequently the development of testing strategies. METHODS: The present study analyzed the seroprevalence of HIV, syphilis, and hepatitis B and C, and the epidemiological profiles of key and general populations tested at a reference public health facility for sexually transmitted infections testing and counseling in the city of Curitiba, Southern Brazil. A cross-sectional study was conducted to report data from 2010 to 2019. RESULTS: A total of 67,448 samples were analyzed, 9,086 of these tested positive, 3,633 (56%) for HIV, 4,978 (77%) for syphilis, 340 (5%) for hepatitis C virus (HCV), and 135 (2%) for hepatitis B virus (HBV). Overall, most of the participants were men (79 to 87%), and predominantly white. For HIV and syphilis, the predominant age groups were 21-30 years old (48 and 50%), HBV 21-40 years old (31%), and HCV 41-60 years old (25%). A high seroprevalence of HIV and syphilis was observed in the investigated key populations with a higher frequency in sex workers, men who have sex with men, and transgender. CONCLUSION: The progressive increase in syphilis cases emphasizes the need for effective interventions to enhance adherence to the use of condoms, and to expand diagnosis and treatment for these key populations.

The association of breastfeeding and other factors on respiratory virus positivity and severity in hospitalized children.

Acute respiratory infections (ARIs) are the most prevalent diseases in children under 5 years old, and viruses are the leading cause. ARIs arise due to numerous factors, including age, contact with siblings or other children in daycare centers, and environmental pollution. Breastfeeding reportedly confers protection against ARIs through bioactive components related to mucous epithelial immunity. This study aimed to evaluate the frequency and severity of viral ARIs in hospitalized children, together with the status and duration of exclusive breastfeeding (EBF) and other associated factors. It comprised an epidemiological surveillance study to investigate respiratory viruses in hospitalized children, in which demographic and clinical data were collected. Overall, 279 patients were included, 190 (68%) had positive viral results, and 132 (47%) were exclusively breastfed. In an adjusted analysis, it was observed that older children, the parents' educational level, and the presence of chronic disease were significantly related to EBF for more than 6 months. No significant differences were observed in viral positivity and disease severity concerning EBF. Whereas the EBF status was associated with a positive rate of virus detection, the significance did not remain after adjustment, and it was not considered a protective factor against ARIs. On the other hand, young age and exposure to tobacco were confirmed as risk factors of frequency and severity, respectively. Such confounding factors can impact the analysis and should be considered in future studies.

HIV, syphilis, hepatitis B and C in key populations: results of a 10-year cross-sectional study, Southern Brazil

ABSTRACT Objective: Although the development of prevention and treatment strategies for sexually transmitted infections in key groups has improved over the years, they still remain a challenge for health systems worldwide. In this context, the objective of this study is to assess the seroprevalence in the tested population, with an emphasis on key populations, aiming at identifying the participants' profile and consequently the development of testing strategies. Methods: The present study analyzed the seroprevalence of HIV, syphilis, and hepatitis B and C, and the epidemiological profiles of key and general populations tested at a reference public health facility for sexually transmitted infections testing and counseling in the city of Curitiba, Southern Brazil. A cross-sectional study was conducted to report data from 2010 to 2019. Results: A total of 67,448 samples were analyzed, 9,086 of these tested positive, 3,633 (56%) for HIV, 4,978 (77%) for syphilis, 340 (5%) for hepatitis C virus (HCV), and 135 (2%) for hepatitis B virus (HBV). Overall, most of the participants were men (79 to 87%), and predominantly white. For HIV and syphilis, the predominant age groups were 21-30 years old (48 and 50%), HBV 21-40 years old (31%), and HCV 41-60 years old (25%). A high seroprevalence of HIV and syphilis was observed in the investigated key populations with a higher frequency in sex workers, men who have sex with men, and transgender. Conclusion: The progressive increase in syphilis cases emphasizes the need for effective interventions to enhance adherence to the use of condoms, and to expand diagnosis and treatment for these key populations.