Interim Influenza Vaccine Effectiveness Against Laboratory-Confirmed Influenza - California, October 2023-January 2024.

Surveillance data can provide rapid, within-season influenza vaccine effectiveness (VE) estimates to guide public health recommendations. Mandatory reporting of influenza vaccine administration to California's immunization information registry began January 1, 2023, and mandatory reporting of all influenza laboratory test results, including negative results, was instituted in California on June 15, 2023. These data, collected by the California Department of Public Health during October 1, 2023-January 31, 2024, were used to calculate interim influenza VE against laboratory-confirmed influenza by comparing the odds of vaccination among case-patients (persons who received a positive influenza laboratory test result) and control patients (those who received a negative influenza laboratory test result). VE was calculated as 1 - adjusted odds ratio using mixed-effects logistic regression, with age, race, and ethnicity as fixed effects and specimen collection week and county as random effects. Overall, during October 1, 2023-January 31, 2024, estimated VE was 45% among persons aged ≥6 months, 56% among children and adolescents aged 6 months-17 years, 48% among adults aged 18-49 years, 36% among those aged 50-64 years, and 30% among those aged ≥65 years. Consistent with some previous influenza seasons, influenza vaccination provided moderate protection against laboratory-confirmed influenza among infants, children, adolescents, and adults. All persons aged ≥6 months without a contraindication to vaccination should receive annual influenza vaccination to reduce influenza illness, severe influenza, and strain on health care resources. Influenza vaccination remains the best way to prevent influenza.

Evaluation of FluSight influenza forecasting in the 2021-22 and 2022-23 seasons with a new target laboratory-confirmed influenza hospitalizations.

Accurate forecasts can enable more effective public health responses during seasonal influenza epidemics. Forecasting teams were asked to provide national and jurisdiction-specific probabilistic predictions of weekly confirmed influenza hospital admissions for one through four weeks ahead for the 2021-22 and 2022-23 influenza seasons. Across both seasons, 26 teams submitted forecasts, with the submitting teams varying between seasons. Forecast skill was evaluated using the Weighted Interval Score (WIS), relative WIS, and coverage. Six out of 23 models outperformed the baseline model across forecast weeks and locations in 2021-22 and 12 out of 18 models in 2022-23. Averaging across all forecast targets, the FluSight ensemble was the 2nd most accurate model measured by WIS in 2021-22 and the 5th most accurate in the 2022-23 season. Forecast skill and 95% coverage for the FluSight ensemble and most component models degraded over longer forecast horizons and during periods of rapid change. Current influenza forecasting efforts help inform situational awareness, but research is needed to address limitations, including decreased performance during periods of changing epidemic dynamics.

Influenza and SARS-CoV-2 Co-infections in California, USA, September 2020-April 2021.

During September 1, 2020-April 30, 2021, the California Department of Public Health, Richmond, California, USA, received 255 positive influenza molecular test results that matched with severe acute respiratory syndrome coronavirus 2 molecular test results; 58 (23%) persons were co-infected. Influenza activity was minimal in California, and co-infections were sporadic.

Adherence to buprenorphine: An analysis of prescription drug monitoring program data.

BACKGROUND: Although buprenorphine is an evidence-based treatment for opioid use disorder (OUD), many individuals discontinue treatment soon after starting. This study assesses predictors of buprenorphine adherence using Prescription Drug Monitoring Program (PDMP) data. METHODS: PDMP data for Philadelphia, Pennsylvania were used to measure 180-day adherence to buprenorphine among new initiates. Adherence was classified using percent days covered (PDC), and new initiates with PDC ≥ 0.80 were classified as adherent. Multivariable logistic regression was conducted to determine factors associated with buprenorphine adherence. RESULTS: Between January 2017 and December 2018, 10,669 Philadelphia residents initiated buprenorphine and 26.6 % remained adherent after 180 days. Demographic factors associated with greater odds of adherence included age category and female sex (aOR: 1.37; 95 % CI: 1.25-1.50). Those filling an opioid prescription, other than buprenorphine, during the follow-up period had lower odds of adherence than those who did not fill an opioid prescription (aOR: 0.62; 95 % CI: 0.50-0.77). Odds of adherence was greater for those on the film formulation (aOR: 1.37; 95 % CI: 1.25-1.50) than the tablet formulation. Those filling medium (aOR: 1.76; 95 % CI: 1.55-2.00) and high dose (aOR: 5.11; 95 % CI: 4.30-6.17) buprenorphine prescriptions had higher odds of adherence than those filling low dose prescriptions. CONCLUSIONS: Individual demographics, receipt of an opioid prescription, buprenorphine formulation, and buprenorphine dose were all associated with adherence to buprenorphine. Ongoing strategies to address OUD need to prioritize increasing retention in long-term evidence-based buprenorphine treatment while also encouraging providers to regularly consult the PDMP to ensure patient compliance.