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.

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).

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.

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.