COVID-19-Associated Hospitalizations Among Vaccinated and Unvaccinated Adults 18 Years or Older in 13 US States, January 2021 to April 2022

Importance

Understanding risk factors for hospitalization in vaccinated persons and the association of COVID-19 vaccines with hospitalization rates is critical for public health efforts to control COVID-19.

Objective

To determine characteristics of COVID-19-associated hospitalizations among vaccinated persons and comparative hospitalization rates in unvaccinated and vaccinated persons.

Design, Setting, and Participants

From January 1, 2021, to April 30, 2022, patients 18 years or older with laboratory-confirmed SARS-CoV-2 infection were identified from more than 250 hospitals in the population-based COVID-19-Associated Hospitalization Surveillance Network. State immunization information system data were linked to cases, and the vaccination coverage data of the defined catchment population were used to compare hospitalization rates in unvaccinated and vaccinated individuals. Vaccinated and unvaccinated patient characteristics were compared in a representative sample with detailed medical record review; unweighted case counts and weighted percentages were calculated.

Exposures

Laboratory-confirmed COVID-19-associated hospitalization, defined as a positive SARS-CoV-2 test result within 14 days before or during hospitalization.

Main Outcomes and Measures

COVID-19-associated hospitalization rates among vaccinated vs unvaccinated persons and factors associated with COVID-19-associated hospitalization in vaccinated persons were assessed.

Results

Using representative data from 192 509 hospitalizations (see Table 1 for demographic information), monthly COVID-19-associated hospitalization rates ranged from 3.5 times to 17.7 times higher in unvaccinated persons than vaccinated persons regardless of booster dose status. From January to April 2022, when the Omicron variant was predominant, hospitalization rates were 10.5 times higher in unvaccinated persons and 2.5 times higher in vaccinated persons with no booster dose, respectively, compared with those who had received a booster dose. Among sampled cases, vaccinated hospitalized patients with COVID-19 were older than those who were unvaccinated (median [IQR] age, 70 [58-80] years vs 58 [46-70] years, respectively; P < .001) and more likely to have 3 or more underlying medical conditions (1926 [77.8%] vs 4124 [51.6%], respectively; P < .001).

Conclusions and Relevance

In this cross-sectional study of US adults hospitalized with COVID-19, unvaccinated adults were more likely to be hospitalized compared with vaccinated adults; hospitalization rates were lowest in those who had received a booster dose. Hospitalized vaccinated persons were older and more likely to have 3 or more underlying medical conditions and be long-term care facility residents compared with hospitalized unvaccinated persons. The study results suggest that clinicians and public health practitioners should continue to promote vaccination with all recommended doses for eligible persons.

The 6 E Framework of Public Health Preparedness for Mass Gatherings-Lessons Learned From Super Bowl LIII, Fulton County, Georgia, 2019

CONTEXT

On February 3, 2019, Atlanta, Georgia, hosted Super Bowl LIII, which is classified as a National Special Security Event. The festivities comprising this major sporting event brought approximately half a million people to Atlanta, which posed significant challenges to the local public health community. As the lead local agency for public health planning, preparedness, and response efforts, Fulton County Board of Health (FCBOH) needed to address multiple specific tasks based on core functional areas outlined in the Emergency Support Function (ESF) 8 (eg, bioterrorism preparedness and epidemiological surveillance).

PROGRAM

To prepare for the Super Bowl, FCBOH developed a systematic approach to ensure community-wide public health preparedness for mass gatherings. This approach came to be known as the 6 E framework, which consists of (1) engaging stakeholders, (2) examining current capabilities and identifying gaps, (3) establishing roles and responsibilities, (4) executing plans to fill gaps, (5) exercising plans, and (6) evaluating impact.

IMPLEMENTATION

We define each step of the 6 E framework and present practical examples of how FCBOH implemented each step when preparing for the Super Bowl. Challenges that FCBOH faced and the lessons learned in the process are illustrated. The 6 E framework provides a systematic approach to community preparedness and allows local health departments to tailor the approach to serve local public health needs.

EVALUATION

The successful implementation of the 6 E framework allowed for stakeholders at the federal, state, and local levels (including law enforcement) to effectively coordinate an epidemiological investigation and response when 4 staff members reported gastrointestinal symptoms after eating at a feeding station.

DISCUSSION

Preparation for the Super Bowl required months of diligent cross-sectoral and cross-jurisdictional partnership building, and the 6 E framework can help other local public health jurisdictions prepare to host major mass gatherings.