The COVID-19 pandemic has highlighted the importance of disease models for situational awareness, decision-making, and planning. From weather to infectious diseases, it has been shown that synthesizing results from multiple models gives more reliable projections than results from any one model alone. Single model projections are particularly problematic for emerging infections where there is considerable uncertainty about basic epidemiological parameters (such as the proportion of asymptomatic individuals, and the waning of immunity), the transmission process, future policies and their impact, and population behavior. Combining outputs from multiple models can be particularly crucial for scenario projections several months into the future; scenario projections address what could happen under a particular set of circumstances (including but not limited to interventions, changes in disease epidemiology, and/or population behavior). The COVID-19 Scenario Modeling Hub was created in December 2020 to provide multiple rounds of real-time, long-term scenario projections in the US for the federal and local health authorities, other decision makers and public health experts, and the general public. Notably, scenario hub projections were used to guide the expansion of the primary COVID-19 vaccine schedule to school-age children in 2021, and booster recommendations in fall 2022. In August 2022, we launched the companion Flu Scenario Modeling Hub.
The COVID-19 Scenario Modeling Hub built on prior pandemic efforts to look at short-term forecasting (as exemplified by the COVID-19 Forecast Hub, which combines the predictions of over 30 models), the Multiple Models for Outbreak Decision Support (MMODS) comparison of the impact of COVID-19 interventions in the early stages of the pandemic, as well as prior multi-model forecasting efforts for flu, dengue, and Ebola, (see also a comparison of multiple models for Ebola interventions). An overview of some key Hubs can be found here.
Round 4 results published in May 14, 2021; MMWR:
Borchering RK, Viboud C, Howerton E, et al. Modeling of Future COVID-19 Cases, Hospitalizations, and Deaths, by Vaccination Rates and Nonpharmaceutical Intervention Scenarios — United States, April–September 2021. MMWR Morb Mortal Wkly Rep 2021; 70:719–724. DOI: http://dx.doi.org/10.15585/mmwr.mm7019e3
MIDAS Webinar on COVID-19 Scenario Modeling Hub presented on April 30, 2021 (available here).
Round 6/7 results published in June 2022; eLife:
S. Truelove, et al., Projected resurgence of COVID-19 in the United States in July-December 2021 resulting from the increased transmissibility of the Delta variant and faltering vaccination. eLife 11, e73584 (2022). DOI: https://doi.org/10.7554/eLife.73584
Round 9 results published in January 2023; Lancet Regional Health -
R. K. Borchering, et al., Impact of SARS-CoV-2 vaccination of children ages 5–11 years on COVID-19 disease burden and resilience to new variants in the United States, November 2021–March 2022: A multi-model study. Lancet Reg Health Am 17, 100398 (2023). DOI: https://doi.org/10.1016/j.lana.2022.100398
Inputs on Advisory Committee on Immunization Practices and Vaccines
and Related Biological Products Advisory Committee meetings 2021-2022:
SMH Round 9 results were presented to ACIP on November 2, 2021, in final testimony prior to the decision being made to vaccinate 5-11 year-old children in the USA.
Preliminary Scenario Modeling Hub results on the reward side of a risk-reward analysis are on the 10th slide in: https://www.cdc.gov/vaccines/acip/meetings/downloads/slides-2021-11-2-3/08-COVID-Oliver-508.pdf
SMH Round 13 & 15 results were presented to VRBPAC on June 28, 2022
and ACIP on September 1, 2022, in the discussion about authorizing
bivalent vaccine boosters:
- Scenario modeling hub presentation of round 13 results at VRBPAC, June 28, 2022: https://www.fda.gov/media/159497/download
- See slides 49-52 in the “Evidence to recommendation Framework: Bivalent COVID-19 vaccine booster doses” presentation, ACIP, September 1, 2022, featuring round 14/15 projections https:/www.cdc.gov/vaccines/acip/meetings/slides-2022-09-01-02.html
Round 14/15 results used in the ACIP decision to authorize the bivalent
booster in fall 2022 in November,11 2022; MMWR:
Rosenblum HG, Wallace M, Godfrey M, et al. Interim Recommendations from the Advisory Committee on Immunization Practices for the Use of Bivalent Booster Doses of COVID-19 Vaccines — United States, October 2022. MMWR Morb Mortal Wkly Rep 2022;71:1436–1441. DOI: http://dx.doi.org/10.15585/mmwr.mm7145a2
Biggerstaff et al 2022 talks about how the CDC used the SMH during
the pandemic in March 2022; Clinical Infectious diseases:
M. Biggerstaff, R. B. Slayton, M. A. Johansson, J. C. Butler, Improving Pandemic Response: Employing Mathematical Modeling to Confront Coronavirus Disease 2019. Clin Infect Dis. 2022 Mar 9;74(5):913-917. DOI: http://dx.doi.org/10.1093/cid/ciab673