Health and Safety Code section 1288.7(a) requires California acute care hospitals to offer influenza vaccine free of charge to all healthcare providers (HCP) or sign a declination form if a HCP chooses not to be vaccinated. Hospitals must report HCP influenza vaccination data to the California Department of Public Health (CDPH), including the percentage of HCP vaccinated. CDPH is required to make this information public on an annual basis [Health and Safety Code section 1288.8 (b)].

California acute care hospitals are required to offer free influenza vaccine to HCP. Hospital HCP must receive an annual vaccine or sign a declination form. Hospitals collect vaccination data for all HCP physically working in the hospital for at least one day during influenza season, regardless of clinical responsibility or patient contact. Hospitals report HCP vaccination rates to the California Department of Public Health (CDPH) and CDPH publishes the hospital results annually. CDPH reports data separately for hospital employees, licensed independent practitioners such as physicians, other contract staff, and trainees and volunteers (Health and Safety Code section 1288.7-1288.8).

Detailed information about the variables included in each dataset are described in the accompanying data dictionaries for the year of interest.

For general information about NHSN, surveillance definitions, and reporting requirements for HCP influenza vaccination, please visit: https://www.cdc.gov/nhsn/hps/vaccination/index.html

To link the CDPH facility IDs with those from other Departments, including OSHPD, please reference the "Licensed Facility Cross-Walk" Open Data table at: https://data.chhs.ca.gov/dataset/licensed-facility-crosswalk.

For information about healthcare personnel influenza vaccinations in California hospitals, please visit: https://www.cdph.ca.gov/Programs/CHCQ/HAI/Pages/HealthcarePersonnelInfluenzaVaccinationReportingInCA_Hospitals.aspx

Chicago residents who are up to date with influenza vaccines by ZIP Code, based on the reported home address and age group of the person vaccinated, as provided by the medical provider in the Illinois Comprehensive Automated Immunization Registry Exchange (I-CARE). “Up to date” refers to individuals aged 6 months and older who have received 1+ doses of influenza vaccine during the current season, defined as the beginning of July (MMWR week 27) through the end of the following June (MMWR week 26). Data Notes: Weekly cumulative totals of people up to date are shown for each combination ZIP Code and age group. Note there are rows where age group is "All ages" so care should be taken when summing rows. Weeks begin on a Sunday and end on a Saturday. Coverage percentages are calculated based on the cumulative number of people in each ZIP Code and age group who are considered up to date as of the week ending date divided by the estimated number of people in that subgroup. Population counts are obtained from the 2020 U.S. Decennial Census. For ZIP Codes mostly outside Chicago, coverage percentages are not calculated because reliable Chicago-only population counts are not available. Actual counts may exceed population estimates and lead to coverage estimates that are greater than 100%, especially in smaller ZIP Codes with smaller populations. Additionally, the medical provider may report a work address or incorrect home address for the person receiving the vaccination, which may lead to over- or underestimation of vaccination coverage by geography. All coverage percentages are capped at 99%. The Chicago Department of Public Health (CDPH) uses the most complete data available to estimate influenza vaccination coverage among Chicagoans, but there are several limitations that impact our estimates. Influenza vaccine administration is not required to be reported in Illinois, except for publicly funded vaccine (e.g., Vaccines for Children, Section 317). Individuals may receive vaccinations that are not recorded in I-CARE, such as those administered in another state, or those administered by a provider that does not submit data to I-CARE, causing underestimation of the number individuals who received an influenza vaccine for the current season. All data are provisional and subject to change. Information is updated as additional details are received and it is, in fact, very common for recent dates to be incomplete and to be updated as time goes on. At any given time, this dataset reflects data currently known to CDPH. Numbers in this dataset may differ from other public sources due to when data are reported and how City of Chicago boundaries are defined. For all datasets related to influenza, see https://data.cityofchicago.org/browse?limitTo=datasets&sortBy=alpha&tags=flu . Data Source: Illinois Comprehensive Automated Immunization Registry Exchange (I-CARE), U.S. Census Bureau 2020 Decennial Census

List of free flu clinics offered throughout Chicago, either by the Department of Public Health or in collaboration with it.

Unlike older versions of the flu shot datasets, this one combines multiple years and will grow over the years. Seasons are now identified by the years they span (e.g., 2018-2019) instead of the year in which they begin (e.g., 2018).

Each season has a filtered view showing only records from that season. These filtered views can be used for almost all purposes as if they were datasets.

This dataset approximately follows https://github.com/codeforamerica/flu-shot-spec/blob/master/data-format.csv and is designed for use by https://github.com/tkompare/chicagoflushots.

For more information about the flu, go to https://www.cityofchicago.org/city/en/depts/cdph/provdrs/flu.html.

Weekly Cumulative Estimated Number of Influenza Vaccinations Administered in Pharmacies and Physical Medical Offices, Adults 18 Years and Older, United States

Archived data are here: https://data.cdc.gov/resource/uxgd-cqqc

• Estimated number of influenza vaccinations among adults 18 years and older is assessed through IQVIA (https://www.iqvia.com/) as a source of information on vaccinations administered in retail pharmacies (include chain, mass merchandise, stores, and independent pharmacies) and physician medical offices.

While vaccine hesitancy has become a salient issue, few studies have examined the influence of international collaboration and vaccine developments on people’s attitudes toward vaccines. The international collaboration especially with China has been an integral part of the field of influenza. In recent years, attitudes toward vaccines and China are both heavily politicized in the U.S. with a deepening partisan divide. Republicans are more likely than Democrats to be vaccine hesitant, and they are also more likely to view China negatively. At the same time, the U.S. has economic, security and medical collaboration with Japan and most Americans display a very positive view of the country. Thus, does a more international collaboration or more country specific vaccine development have an influence on U.S. vaccine hesitancy? This study conducts a survey-embedded question-wording experiment to assess the roles of US-China and US-Japan collaboration and partisanship in people’s willingness to get the flu vaccine. Despite the previously successful and effective US-China collaboration, this study finds that respondents especially Republicans are much less likely to receive a US-China flu vaccine than a US-Japan or US alone. Interestingly, both Democrats and Republicans are as willing to receive a US-Japan vaccine as US alone. These results point to critical roles of partisanship and international relations.

• Weekly Influenza Vaccination Coverage and intent among adults 18 Years and Older by Demographic Characteristics and Jurisdiction

• Weekly estimates of influenza vaccination coverage and intent for vaccination among adults 18 years and older are calculated using data from the National Immunization Survey–Adult COVID Module (NIS–ACM) (https://www.cdc.gov/nis/about/index.html).

Analysis of ‘Chicago Flu Shot Clinic Locations - 2012’ provided by Analyst-2 (analyst-2.ai), based on source dataset retrieved from https://www.kaggle.com/chicago/chicago-flu-shot-clinic-locations-2012 on 12 November 2021.

--- Dataset description provided by original source is as follows ---

Content

List of Chicago Department of Public Health free flu clinics offered throughout the city. For more information about the flu, go to http://bit.ly/9uNhqG.

Context

This is a dataset hosted by the City of Chicago. The city has an open data platform found here and they update their information according the amount of data that is brought in. Explore the City of Chicago using Kaggle and all of the data sources available through the City of Chicago organization page!

• Update Frequency: This dataset is updated annually.

Acknowledgements

This dataset is maintained using Socrata's API and Kaggle's API. Socrata has assisted countless organizations with hosting their open data and has been an integral part of the process of bringing more data to the public.

Cover photo by Hush Naidoo on Unsplash
Unsplash Images are distributed under a unique Unsplash License.

--- Original source retains full ownership of the source dataset ---

IntroductionGuidelines for the management of rheumatoid arthritis (RA) recommend using influenza and pneumococcal vaccinations to mitigate infection risk. The level of adherence to these guidelines is not well known in the UK. The aims of this study were to describe the uptake of influenza and pneumococcal vaccinations in patients with RA in the UK, to compare the characteristics of those vaccinated to those not vaccinated and to compare vaccination rates across regions of the UK.MethodsA retrospective cohort study of adults diagnosed with incident RA and treated with non-biologic immunosuppressive therapy, using data from a large primary care database. For the influenza vaccination, patients were considered unvaccinated on 1st September each year and upon vaccination their status changed to vaccinated. For pneumococcal vaccination, patients were considered vaccinated after their first vaccination until the end of follow-up. Patients were stratified by age 65 at the start of follow-up, given differences in vaccination guidelines for the general population.ResultsOverall (N = 15,724), 80% patients received at least one influenza vaccination, and 50% patients received a pneumococcal vaccination, during follow-up (mean 5.3 years). Of those aged below 65 years (N = 9,969), 73% patients had received at least one influenza vaccination, and 43% patients received at least one pneumococcal vaccination. Of those aged over 65 years (N = 5,755), 91% patients received at least one influenza vaccination, and 61% patients had received at least one pneumococcal vaccination. Those vaccinated were older, had more comorbidity and visited the GP more often. Regional differences in vaccination rates were seen with the highest rates in Northern Ireland, and the lowest rates in London.ConclusionsOne in five patients received no influenza vaccinations and one in two patients received no pneumonia vaccine over five years of follow-up. There remains significant scope to improve uptake of vaccinations in patients with RA.

• Weekly Cumulative Percentage of Children 6 Months–17 Years Who Are Up to Date with COVID-19 Vaccines and Comparison Between 2023–24 and 2024–25 by Jurisdiction.

• Weekly estimates of COVID-19 vaccination coverage and parental intent for vaccination among children through December 31, 2023, were calculated using data from the National Immunization Survey–Child COVID Module (NIS–CCM). The NIS–CCM was discontinued at the end of 2023 and questions regarding COVID-19 vaccination status and intent were added to the National Immunization Survey–Flu (NIS–Flu) (https://www.cdc.gov/nis/about/index.html).

This guidance document applies to sponsors seeking authorization for annual updates to influenza vaccines. The document covers the process, data requirements, and associated timelines for the submission, review, and lot release of seasonal influenza vaccines in Canada.

BackgroundTo identify determinants influencing Canadian parents’ decision not to vaccinate their children aged 6 months to 17 years against seasonal influenza.MethodsData from the 2022 Childhood COVID-19 Immunization Coverage Survey, a national survey of approximately 10,500 Canadian parents/guardians and their children, was analyzed. The survey examined influenza vaccine coverage, parental perspectives on vaccines, reasons for hesitancy, and factors influencing immunization. Socio-demographic characteristics, including ethnicity, household income, working sector, educational attainment, and prevalence of chronic medical conditions among children were considered. Historical vaccine uptake and the impact of the COVID-19 pandemic on immunization decisions were also reviewed. Key determinants of non-vaccination in the 2021–2022 influenza season were analyzed using multivariable logistic regression, with a statistical significance level set at p-value

This dataset represents preliminary weekly estimates of cumulative U.S. RSV-associated hospitalizations for the 2024-2025 season. Estimates are preliminary, and use reported weekly hospitalizations among laboratory-confirmed respiratory syncytial virus (RSV) infections. The data are updated week-by-week as new RSV-associated hospitalizations are reported to CDC from the RSV-NET surveillance system and include both new admissions that occurred during the reporting week, as well as those admitted in previous weeks that may not have been included in earlier reporting. Each week CDC estimates a range (i.e., lower estimate and an upper estimate) of RSV-associated hospitalizations that have occurred since October 1, 2024. For details, please refer to the publication [7].

Note: Data are preliminary and subject to change as more data become available. Rates for recent RSV-associated hospital admissions are subject to reporting delays; as new data are received each week, previous rates are updated accordingly.

Note: Preliminary burden estimates are not inclusive of data from all RSV-NET sites. Due to model limitations, sites with small sample sizes can impact estimates in unpredictable ways and are excluded for the benefit of model stability. CDC is working to address model limitations and include data from all sites in final burden estimates.

References

1. Reed C, Chaves SS, Daily Kirley P, et al. Estimating influenza disease burden from population-based surveillance data in the United States. PLoS One. 2015;10(3):e0118369. https://doi.org/10.1371/journal.pone.0118369 
2. Rolfes, MA, Foppa, IM, Garg, S, et al. Annual estimates of the burden of seasonal influenza in the United States: A tool for strengthening influenza surveillance and preparedness. Influenza Other Respi Viruses. 2018; 12: 132– 137. https://doi.org/10.1111/irv.12486
3. Tokars JI, Rolfes MA, Foppa IM, Reed C. An evaluation and update of methods for estimating the number of influenza cases averted by vaccination in the United States. Vaccine. 2018;36(48):7331-7337. doi:10.1016/j.vaccine.2018.10.026 
4. Collier SA, Deng L, Adam EA, Benedict KM, Beshearse EM, Blackstock AJ, Bruce BB, Derado G, Edens C, Fullerton KE, Gargano JW, Geissler AL, Hall AJ, Havelaar AH, Hill VR, Hoekstra RM, Reddy SC, Scallan E, Stokes EK, Yoder JS, Beach MJ. Estimate of Burden and Direct Healthcare Cost of Infectious Waterborne Disease in the United States. Emerg Infect Dis. 2021 Jan;27(1):140-149. doi: 10.3201/eid2701.190676. PMID: 33350905; PMCID: PMC7774540.
5. Reed C, Kim IK, Singleton JA,  et al. Estimated influenza illnesses and hospitalizations averted by vaccination–United States, 2013-14 influenza season. MMWR Morb Mortal Wkly Rep. 2014 Dec 12;63(49):1151-4. https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6349a2.htm 
6. Reed C, Angulo FJ, Swerdlow DL, et al. Estimates of the Prevalence of Pandemic (H1N1) 2009, United States, April–July 2009. Emerg Infect Dis. 2009;15(12):2004-2007. https://dx.doi.org/10.3201/eid1512.091413  
7. Devine O, Pham H, Gunnels B, et al. Extrapolating Sentinel Surveillance Information to Estimate National COVID-19 Hospital Admission Rates: A Bayesian Modeling Approach. Influenza and Other Respiratory Viruses. https://onlinelibrary.wiley.com/doi/10.1111/irv.70026. Volume18, Issue10. October 2024.
8. https://www.cdc.gov/covid/php/covid-net/index.html">COVID-NET | COVID-19 | CDC 
9. https://www.cdc.gov/covid/hcp/clinical-care/systematic-review-process.html 
10. https://academic.oup.com/pnasnexus/article/1/3/pgac079/6604394?login=false">Excess natural-cause deaths in California by cause and setting: March 2020 through February 2021 | PNAS Nexus | Oxford Academic (oup.com)
11. Kruschke, J. K. 2011. Doing Bayesian data analysis: a tutorial with R and BUGS. Elsevier, Amsterdam, Section 3.3.5.

Vaccination Coverage among Pregnant Women

• Data on influenza and tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccination coverage at the state level from the Pregnancy Risk Assessment Monitoring System (PRAMS) for women who had a recent live birth by age and race/ethnicity.

• Additional information available at https://www.cdc.gov/vaccines/imz-managers/coverage/adultvaxview/index.html and https://www.cdc.gov/flu/fluvaxview/index.htm

a Among the 4 hospitals which used IRDTs that can detect A(H1N1)pdm09.Effectiveness of Influenza Vaccine for Preventing Influenza Hospitalization.