Effectiveness of COVID-19 mRNA Vaccines in Preventing COVID-19-Associated Outpatient Visits and Hospitalizations Among American Indian and Alaska Native Persons, January-November 2021: A Test-Negative Case-Control Analysis Using Surveillance Data.

Background: Despite the disproportionate morbidity and mortality experienced by American Indian and Alaska Native (AI/AN) persons during the coronavirus disease 2019 (COVID-19) pandemic, few studies have reported vaccine effectiveness (VE) estimates among these communities.

Methods: We conducted a test-negative case-control analysis among AI/AN persons aged ≥12 years presenting for care from January 1, 2021, through November 30, 2021, to evaluate the effectiveness of mRNA COVID-19 vaccines against COVID-19-associated outpatient visits and hospitalizations. Cases and controls were patients with ≥1 symptom consistent with COVID-19-like illness; cases were defined as those test-positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and controls were defined as those test-negative for SARS-CoV-2.

Mother-To-Child Transmission of HIV in Adolescents and Young Women: Findings From a National Prospective Cohort Survey, Zimbabwe, 2013-2014.

Purpose: We assessed 18-month cumulative mother-to-child HIV transmission (MTCT) risk and risk factors for no antiretroviral medication use during pregnancy among adolescent, young women, and adult mothers in Zimbabwe.

Methods: We analyzed data from a prospective survey of 1,171 mother-infant pairs with HIV-exposed infants aged 4-12 weeks who were recruited from 151 immunization clinics from February to August 2013. HIV-exposed infants were followed until diagnosed with HIV, death, or age 18 months.