Late-Season Influenza Vaccine Effectiveness Against Medically Attended Outpatient Illness, United States, December 2022-April 2023.

Background: The 2022-23 US influenza season peaked early in fall 2022.

Methods: Late-season influenza vaccine effectiveness (VE) against outpatient, laboratory-confirmed influenza was calculated among participants of the US Influenza VE Network using a test-negative design.

Results: Of 2561 participants enrolled from December 12, 2022 to April 30, 2023, 91 laboratory-confirmed influenza cases primarily had A(H1N1)pdm09 (6B.

Influenza Vaccine Effectiveness Against Influenza A(H3N2)-Related Illness in the United States During the 2021-2022 Influenza Season.

Background: In the United States, influenza activity during the 2021-2022 season was modest and sufficient enough to estimate influenza vaccine effectiveness (VE) for the first time since the beginning of the coronavirus disease 2019 pandemic. We estimated influenza VE against laboratory-confirmed outpatient acute illness caused by predominant A(H3N2) viruses.

Methods: Between October 2021 and April 2022, research staff across 7 sites enrolled patients aged ≥6 months seeking outpatient care for acute respiratory illness with cough.

25-hydroxyvitamin D is a predictor of COVID-19 severity of hospitalized patients.

Objectives: Studies investigating the association between vitamin D and severity of COVID-19 have mixed results perhaps due to immunoassay assessment of total 25-hydroxyvitamin D (tD) (the sum of 25-hydroxyvitamin-D2 [25-OH-D2] and 25-hydroxyvitamin-D3 [25-OH-D3]). Liquid chromatography tandem mass spectrometry (LC-MS/MS) has high analytical specificity and sensitivity for 25-OH-D2 and 25-OH-D3, and thus enables a more accurate assessment of impact on COVID-19 outcomes.

Methods: We established reference intervals for 25-OH-D3 and tD using LC-MS/MS.

Surveillance genome sequencing reveals multiple SARS-CoV-2 variants circulating in central Texas, USA, with a predominance of delta variant and review of vaccine breakthrough cases.

As surges in the COVID-19 pandemic have continued worldwide, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has mutated, spawning several new variants, and impacting, to various degrees, transmission, disease severity, diagnostics, therapeutics, and natural and vaccine-induced immunity. Baylor Scott & White Health has implemented, along with laboratory diagnosis, SARS-CoV-2 sequencing to identify variants in its geographical service area. We analyzed virus sequencing results of specimens collected across Central Texas and found dramatic changes in variant distribution in the first half of 2021.