Since vaccine distribution began in the U.S. on Dec. 14, more than 55 million doses have been administered, reaching 11.9 percent of the total U.S. population, according to federal data collected by the Centers for Disease Control and Prevention (CDC). The U.S. is currently administering more than 1.8 million shots a day. States will receive 13.5 million doses this week, up from 11 million nationwide last week and a 57 percent increase since President Biden took office. With the recent purchase of 200 million additional doses by the administration, it is projected that the U.S. is on target to have enough supply for 300 million Americans by the end of July. In Pennsylvania, 10.7 percent of the population has received at least one dose and 3.6 percent, two doses. That is assuming that all vaccine administrators have inputted their data in PA-SIIS, which is not the case and is one of the reasons the state is reconfiguring its distribution and vaccination strategy. Over the course of the next few weeks, the state will narrow the number of organizations administering the vaccine, with hospitals, health systems, pharmacies and FQHCs prioritized. Distribution decisions will also be influenced by each provider’s effectiveness in getting vaccine in eligible 1A arms within seven days of receipt and analysis of COVID-19 impact in the region. Right now, however, the Pennsylvania Department of Health (DOH) is focusing on a course correction to address demand for second dose supply that exceeds total vaccine supply received by the state. Vaccine supply and distribution will be bumpy for a few weeks, but we all hope that predictability and stability of supply will improve thereafter. Sometimes, when the present is challenging and the future hard to envision, it is good to look back. Watch this 3-minute video on polio vaccine rollout.