Risk Factors Associated with Mortality in Hospitalized Patients with COVID-19 during the Omicron Wave in Brazil.

Considering the imminence of new SARS-CoV-2 variants and COVID-19 vaccine availability, it is essential to understand the impact of the disease on the most vulnerable groups and those at risk of death from the disease. To this end, the odds ratio (OR) for mortality and hospitalization was calculated for different groups of patients by applying an adjusted logistic regression model based on the following variables of interest: gender, booster vaccination, age group, and comorbidity occurrence. A massive number of data were extracted and compiled from official Brazilian government resources, which include all reported cases of hospitalizations and deaths associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Brazil during the "wave" of the Omicron variant (BA.1 substrain). Males (1.242; 95% CI 1.196-1.290) aged 60-79 (3.348; 95% CI 3.050-3.674) and 80 years or older (5.453; 95% CI 4.966-5.989), and hospitalized patients with comorbidities (1.418; 95% CI 1.355-1.483), were more likely to die. There was a reduction in the risk of death (0.907; 95% CI 0.866-0.951) among patients who had received the third dose of the anti-SARS-CoV-2 vaccine (booster). Additionally, this big data investigation has found statistical evidence that vaccination can support mitigation plans concerning the current scenario of COVID-19 in Brazil since the Omicron variant and its substrains are now prevalent across the entire country.

Effect of maternal Tdap on infant antibody response to a primary vaccination series with whole cell pertussis vaccine in São Paulo, Brazil.

BACKGROUND: Maternal Tetanus, diphtheria, and acellular pertussis (Tdap) vaccination provides antibody transfer to newborn infants and may affect their antibody response to the primary vaccination series. This study aimed to assess the effect of Tdap vaccination during pregnancy on infant antibody response to the whole cell pertussis (DTwP) primary series. METHODS: Plasma from 318 pregnant women (243 Tdap-vaccinated and 75 unvaccinated) and their infants (cord blood) was collected at delivery; infant blood was again collected at 2 and 7 months, before and after their primary DTwP series. Anti-pertussis toxin (PT), pertactin (PRN), filamentous hemagglutinin (FHA), fimbriae 2/3 (FIM) and adenylate cyclase toxin (ACT) IgG antibodies were quantified by a microsphere-based multiplex antibody capture assay and anti-PT neutralizing antibodies by the Real Time Cell analysis system. RESULTS: Infant geometric mean concentrations (GMCs) of IgG anti-Tdap antigens were significantly higher (p < 0.001) among the Tdap-vaccinated (PT: 57.22 IU/mL; PRN: 464.86 IU/mL; FHA: 424.0 IU/mL), versus the unvaccinated group (4 IU/mL, 15.43 IU/mL, 31.99 IU/mL, respectively) at delivery. Anti-FIM and ACT GMCs were similar between the two groups. At 2 months of age, anti-PT, PRN, and FHA GMCs remained higher (p < 0.001) in the Tdap-vaccinated group (12.64 IU/mL; 108.76 IU/mL; 87.41 IU/mL, respectively) than the unvaccinated group (1.02 IU/mL; 4.46 IU/mL; 6.89 IU/mL). However, at 7 months, after receiving the third DTwP dose, the anti-PT GMC was higher (p = 0.016) in the unvaccinated group (7.91 IU/mL) compared to the vaccinated group (2.27 IU/mL), but without differences for anti-PRN, FHA, FIM and ACT GMCs. CONCLUSION: Elevated antibody levels suggest that maternal Tdap vaccination might protect infants until 2 months of age. Reduced anti-PT levels at 7 months indicate potential blunting of immune response in infants. Surveillance would help determine if blunting alters vaccine immunity and impacts pertussis prevention in infants.

Influenza B outbreak on a cruise ship off the São Paulo Coast, Brazil.

BACKGROUND: In February 2012, crew and passengers of a cruise ship sailing off the coast of São Paulo, Brazil, were hospitalized for acute respiratory illness (ARI). A field investigation was performed to identify the disease involved and factors associated. METHODS: Information on passengers and crew with ARI was obtained from the medical records of hospitalized individuals. Active case finding was performed onboard the ship. ARI was defined as the presence of one nonspecific symptom (fever, chills, myalgia, arthralgia, headache, or malaise) and one respiratory symptom (cough, nasal congestion, sore throat, or dyspnea). A case-control study was conducted among the crew. The cases were crew members with symptoms of influenza-like illness (ILI) (fever and one of the following symptoms: cough, sore throat, and dyspnea) in February 2012. The controls were asymptomatic crew members. RESULTS: The study identified 104 ARI cases: 54 (51.9%) crew members and 50 (49.1%) passengers. Among 11 ARI hospitalized cases, 6 had influenza B virus isolated in nasopharyngeal swab. One mortality among these patients was caused by postinfluenza Staphylococcus aureus pneumonia. The crew members housed in the two lower decks and those belonging to the 18- to 32-year-old age group were more likely to develop ILI [odds ratio (OR) = 2.39, 95% confidence interval (CI) 1.09-5.25 and OR = 3.72, CI 1.25-11.16, respectively]. CONCLUSIONS: In February 2012, an influenza B outbreak occurred onboard a cruise ship. Among crew members, ILI was associated with lower cabin location and younger age group. This was the first influenza outbreak detected by Brazilian public health authorities in a vessel cruising in South American waters.