English 
Spanish 
The Effect of Pertussis Vaccination During Pregnancy on Pertussis and Diphtheria Immunity in Children at 3 and 4 Years of Age
Authors followed children born to tetanus-diphtheria-acellular pertussis-vaccinated (n = 47) and unvaccinated (n = 22) mothers to 4 years of age. At both 3 and 4 years, children born to Tdap-vaccinated mothers had lower anti-pertussis toxin and anti-diphtheria toxin IgG concentrations than control children, and pertussis toxin seropositivity and diphtheria seroprotection rates were low in both groups. After a preschool acellular pertussis booster at 4 years, antibody concentrations increased to comparable levels in both groups. Tdap vaccination during pregnancy induced high antibody levels in young infants against pertussis but was associated with lower IgG levels against all measured antigens at 3 years, and lower anti-PT and anti-DT IgG levels at 4 years. At 28 days after 4-year booster vaccination, no significant between-group differences were observed in IgG GMCs or PTNA titers. The low prediphtheria seroprotection at 3–4 years in both groups argues for reconsidering both the timing of preschool boosters and the use of a maternal pertussis-only vaccine in place of Tdap, particularly where the risk of diphtheria is rising.
Effectiveness of Diphtheria and Tetanus Toxoids and Acellular Pertussis Vaccine in Children Aged 6 Months–6 Years During a Statewide Pertussis Outbreak — Alaska, May–November 2024Â
After a period of low U.S. pertussis incidence during and shortly after the COVID-19 pandemic, incidence increased in 2024. Data on the real-world effectiveness of diphtheria and tetanus toxoids and acellular pertussis vaccine (DTaP) against pertussis during this disease resurgence are limited. In response to documentation of a record high pertussis incidence in Alaska during May–November 2024, DTaP vaccine effectiveness (VE) against pertussis in Alaska children aged 6 months–6 years was evaluated. Adjusted VE was 96.2% among children who had completed the three-dose primary DTaP series and 85.3% among those who were partially vaccinated. Compared with children who had received ≥3 DTaP doses, the odds of laboratory-confirmed pertussis were approximately 26 times as high in unvaccinated children (adjusted odds ratio [OR] = 26.1), and approximately four times as high in those who had received 1–2 DTaP doses (adjusted OR = 3.8). These findings reinforce the importance of following pertussis vaccination recommendations to protect for children from the disease and reduce the occurrence of pertussis outbreaks.
Subacute Sclerosing Panencephalitis after Measles Outbreaks, the Philippines, 2007–2022
Subacute sclerosing panencephalitis (SSPE) is a delayed, almost uniformly fatal complication of measles. The Philippines had measles outbreaks in 2010–2011, 2013, and 2018–2019; the last was the largest in the World Health Organization Western Pacific Region. Published SSPE data from the Philippines end in 2015. This group reviewed all 20 children admitted with SSPE to a tertiary pediatric hospital in Quezon City during 2007–2022 and estimated year of measles infection. Median patient age was 6.2 years at hospital admission and 0.7 years at reported measles illness. Five (25.0%) of 20 admissions occurred in 2022, and estimated infection dates placed four patients within the 2018–2019 outbreak; all were admitted during 2020–2022. Given the multiyear latency of SSPE, additional cases might emerge over coming years. Because SSPE is latent for years after initial infection, those cases “most likely represent the leading edge of a post outbreak wave,” notes the report, and “additional cases might emerge over the coming years.”
Effect of Fluvoxamine and Metformin for Fatigue in Patients With Long COVID: An Adaptive Randomized Trial
These are the results of a multicenter, randomized, placebo-controlled, adaptive trial (REVIVE-TOGETHER) to evaluate the efficacy of metformin and fluvoxamine for treatment of fatigue associated with Long COVID. The trial was conducted at 22 participating outpatient sites in Brazil between October 2023 and February 2025. A total of 399 participants were randomly assigned in a 1:1:1 ratio to fluvoxamine, metformin, or matching placebo using a centralized, web-based randomization system stratified by site with variable block sizes. The primary outcome was the change in Fatigue Severity Score from baseline to day 60. They found fluvoxamine for Long COVID–related fatigue reduced fatigue severity as measured by the FSS. These effects had a posterior probability of superiority of 99% compared with placebo. Improvements in health-related quality of life, assessed via the EQ-5D-5L, were also observed at days 60 and 90.
Situation Dashboards
World Health Organization (WHO)
Johns Hopkins University (JHU)
COVID-19 in US and Canada
