Sara L Loo Emily Howerton Lucie Contamin Claire P. Smith Erica Carcelén Katie Yan Samantha J Bents John Levander Jessi Espino Joseph C Lemaitre Koji Sato Clif D McKee Alison L Hill Matteo Chinazzi Jessica T Davis Kunpeng Mu Alessandro Vespignani Erik T Rosenstrom Sebastian A Rodriguez-Cartes Julie S Ivy Maria E Mayorga Julie L Swann Guido Espana Sean Cavany Sean M Moore Alex Perkins Shi Chen Rajib Paul Daniel Janies Jean-Claude Thill Ajitesh Srivastava Majd Al Aawar Kaiming Bi Shraddha R Bandekar Anass Bouchnita Spencer J Fox Lauren A. Meyers Przemyslaw Porebski Srinivasan Venkatramanan Aniruddha Adiga Benjamin Hurt Brian Klahn Joseph Outten Jiangzhuo Chen Henning Mortveit Amanda Wilson Stefan Hoops Parantapa Bhattacharya Dustin Machi Anil Vullikanti Bryan Lewis Madhav Marathe Harry Hochheiser Michael C. Runge Katriona Shea Shaun Truelove Cécile Viboud Justin Lessler Sung-mok Jung 2024 <div id="section1" class="section toc-section"><h3>Background</h3><p>Coronavirus Disease 2019 (COVID-19) continues to cause significant hospitalizations and deaths in the United States. Its continued burden and the impact of annually reformulated vaccines remain unclear. Here, we present projections of COVID-19 hospitalizations and deaths in the United States for the next 2 years under 2 plausible assumptions about immune escape (20% per year and 50% per year) and 3 possible CDC recommendations for the use of annually reformulated vaccines (no recommendation, vaccination for those aged 65 years and over, vaccination for all eligible age groups based on FDA approval).</p></div><div id="section2" class="section toc-section"><h3>Methods and findings</h3><p>The COVID-19 Scenario Modeling Hub solicited projections of COVID-19 hospitalization and deaths between April 15, 2023 and April 15, 2025 under 6 scenarios representing the intersection of considered levels of immune escape and vaccination. Annually reformulated vaccines are assumed to be 65% effective against symptomatic infection with strains circulating on June 15 of each year and to become available on September 1. Age- and state-specific coverage in recommended groups was assumed to match that seen for the first (fall 2021) COVID-19 booster. State and national projections from 8 modeling teams were ensembled to produce projections for each scenario and expected reductions in disease outcomes due to vaccination over the projection period.</p><p>From April 15, 2023 to April 15, 2025, COVID-19 is projected to cause annual epidemics peaking November to January. In the most pessimistic scenario (high immune escape, no vaccination recommendation), we project 2.1 million (90% projection interval (PI) [1,438,000, 4,270,000]) hospitalizations and 209,000 (90% PI [139,000, 461,000]) deaths, exceeding pre-pandemic mortality of influenza and pneumonia. In high immune escape scenarios, vaccination of those aged 65+ results in 230,000 (95% confidence interval (CI) [104,000, 355,000]) fewer hospitalizations and 33,000 (95% CI [12,000, 54,000]) fewer deaths, while vaccination of all eligible individuals results in 431,000 (95% CI: 264,000–598,000) fewer hospitalizations and 49,000 (95% CI [29,000, 69,000]) fewer deaths.</p></div><div id="section3" class="section toc-section"><h3>Conclusions</h3><p>COVID-19 is projected to be a significant public health threat over the coming 2 years. Broad vaccination has the potential to substantially reduce the burden of this disease, saving tens of thousands of lives each year.</p></div> application/pdf 10.1371/journal.pmed.1004387 en PLoS Potential impact of annual vaccination with reformulated COVID-19 vaccines: Lessons from the US COVID-19 scenario modeling hub article