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The purpose of this study is to assess the vaccine response to the COVID-19 outbreak installed at the institution. To conduct this case report, 36 individuals were evaluated, among residents and employees of this institution. Blood samples were collected by venipuncture and the presence of antibodies to SARS-CoV-2 (total antibodies, IgG and IgM) were analysed in these samples; 25% of patients/staff (n = 9) seroconverted with only the first dose of CoronaVac® in just 14 days after the first dose of the vaccine. These individuals did not developed symptoms of COVID-19 during the outbreak that occurred at the institution. Vaccine response to CoronaVac®, after an outbreak of COVID-19 at the studied institution, was higher than the response postulated in other previously published studies with detection of SARS-CoV-2 antibodies before the second dose of the vaccine. [ABSTRACT FROM AUTHOR]

Universal immunization against hepatitis B has contributed to reducing incidence of the disease, but older individuals remain susceptible to acquiring the hepatitis B virus worldwide. Thus, this study aimed to investigate the epidemiology of HBV infection in individuals aged 50 years and over in central Brazil and to evaluate the immunogenicity of the monovalent vaccine against hepatitis B in this age group using two vaccine regimens. Method: Initially, a cross-sectional and analytical study was carried out to investigate the epidemiology of hepatitis B. Then, individuals without proof of vaccination for hepatitis B were recruited for a phase IV randomized and controlled clinical trial using two vaccine regimens: Intervention Regimen (IR) (three doses of 40 μg at months 0, 1 and 6) vs. Comparison Regimen (CR) (three doses of 20 μg at months 0, 1 and 6). Results: The overall prevalence of exposure to HBV was 16.6% (95% CI: 14.0%–9.5%). In the clinical trial, statistical differences in protective titers were observed (p = 0.007; IR 96% vs. CR 86%) and the geometric mean of anti-HBs titers was higher in individuals who received the IR (518.2 mIU/mL vs. 260.2 mIU/mL). In addition, the proportion of high responders was higher among those who received the IR (65.3%). Conclusion: reinforced doses should be used in individuals aged 50 years or older to overcome the lower efficacy of the vaccine against hepatitis B. [ABSTRACT FROM AUTHOR]

Objective: To present an updated review of recommendations for the vaccination of children with immune-mediated diseases, with an emphasis on rheumatic and inflammatory diseases. Source of data: Studies published in the PubMed and Scielo databases between 2002 and 2022, Guidelines of Brazilian Scientific Societies, Manuals and Technical Notes of the Ministry of Health of Brazil, on current immunization schedules for special populations. Data synthesis: Immunosuppressive drugs and biological agents reduce the immunogenicity of vaccines and favor susceptibility to infections. The safety and efficacy of immunogens are important points for vaccination in children with immune-mediated diseases. The safety threshold of a vaccine applied to immunocompromised individuals can be reduced when compared to healthy individuals. Very often, the recommendations for the immunization of children with immunemediated diseases follow the recommendations for immunocompromised patients. Vaccination against COVID-19, on the other hand, should ideally occur when the disease is stabilized and in the absence of a low degree of immunosuppression. The patients should be informed about the possibility that the immunization may fail during treatment with immunosuppressants. Specific vaccination schedules should be considered to ensure better protection. Conclusions: Recent studies have allowed updating the recommendations on the safety and immunogenicity of vaccination in children with immune-mediated diseases, especially for live attenuated vaccines. There is a scarcity of data on the safety and efficacy of COVID-19 vaccines in patients, particularly pediatric patients, with rheumatic diseases. The completion of ongoing studies is expected to help guide recommendations on COVID-19 vaccines in this group of patients. [ABSTRACT FROM AUTHOR]

This analysis compares and systematizes some of the milestones (between December 2020 and October 2021) in the approval by Brazil and Chile of the CoronaVac vaccine made by the Chinese laboratory Sinovac, with regard to how the efficacy and immunogenicity of the vaccine was determined. To this end, a comprehensive analysis was conducted of official public documentation of the vaccine's approval in both countries; likewise, relevant technical articles on the subject, as well as dissemination and discussion in the media were considered. In both cases, a wide range of private and public actors expressed clearly competing interests in the measurement and dissemination of figures on the vaccine's efficacy. This reveals the challenges that middle-income countries face--and will continue to face--when certifying the quality of products in a pandemic period, and the need to institutionally strengthen regulatory authorities to ensure a sound and accurate evaluation of vaccine quality, in terms of safety and efficiency. [ABSTRACT FROM AUTHOR]