Tracking Emerging Public Health Challenges – February 16,, 2026 – COVID
Their results show how quickly respiratory pandemics can expand and why stopping them early is so challenging. Published in the journal Proceedings of the National Academy of Sciences, the research is the first to directly compare how these two pandemics moved through U.S. metropolitan areas.
Both outbreaks had major consequences in the United States. The 2009 H1N1 flu pandemic led to 274,304 hospitalizations and 12,469 deaths. The COVID-19 pandemic has been even more devastating, with 1.2 million confirmed deaths reported so far.
The researchers aimed to understand how these pandemics traveled geographically in order to improve planning for future outbreaks. To do this, they combined detailed information about how each virus spreads with computer models that accounted for air travel, everyday commuting, and the possibility of superspreading events. Their analysis focused on more than three hundred metropolitan areas across the U.S.
The simulations revealed that both pandemics were already circulating widely in most metro areas within just a few weeks. This widespread transmission often occurred before early case detection or government response measures were in place. Although H1N1 and COVID-19 followed different routes between locations, both relied on shared transmission hubs, including major metro areas such as New York and Atlanta. Air travel played a much larger role than commuting in driving this rapid spread. At the same time, unpredictable transmission patterns added significant uncertainty, making it difficult to anticipate where outbreaks would emerge in real time.” (1)
1.How COVID and H1N1 swept through U.S. cities in just weeks, https://www.sciencedaily.com/releases/2026/02/260207092906.htm
Scientists Figured Out the Problem With Johnson & Johnson’s COVID Vaccine, By Roxanne Khamsi, https://www.theatlantic.com/science/2026/02/covid-vaccines-blood-clotting-answer/685966/
curated by Jonathan M. Metsch, Dr.P.H.
Clinical Professor of Environmental Medicine, Icahn School of Medicine at Mount Sinai