The list of issues, or playbook, covered normal conditions as well as pandemic conditions. During normal conditions, there was no discussion of estimating and building up stockpiles for use in emergencies. In the United States; the Strategic National Stockpile's stock of masks used against the 2009 flu pandemic was not replenished by the Obama administration or by the Trump administration. The 2017 guidelines note that a vaccine for the 2009 "H1N1pdm09" swine flu virus took eight months before it was available for distribution at the end of 2009. A vaccine for the 2003 SARS virus took 13 years to develop, and was ready for human trials in 2016, which have not yet happened. A vaccine for the 2009 MERS virus took ten years to develop, and began human trials in 2019. Nevertheless, the guidelines said only six months would be needed to develop and distribute a vaccine for the next pandemic, telling schools and day cares they might need to close that long. However the guidelines told businesses to expect only up to two weeks of school closures, saying employees might need to stay home two weeks with their children. The guidelines did not expect any business closures, although studies had long predicted 80% drops in arts, entertainment, and recreation, and 5% to 10% drops in other economic activity over a year, with more severe drops in peak months. The pandemic preparation studies did not address government action to help business, nor the recovery path. The guidelines anticipated "during a pandemic, infection in a localized area can last about six to eight weeks." The 2017 guidelines listed steps which could take place, up to voluntary home isolation of sick people, and voluntary home quarantine of their contacts for up to three days. There was no discussion or planning for closing businesses or ordering people to stay home, which may explain officials' delays in deciding on stay-at-home orders in the 2020 COVID-19 pandemic and lack of preparation to distinguish non-essential from essential workers, and to protect essential workers. In the 1918 flu pandemic many cities closed at least bars, for up to six weeks, and most cities had mandatory isolation and quarantine of sick people and their contacts. Cities with the most severe closures had the best economic recovery. The guidelines told businesses to be ready to keep workers 3 feet apart, though the guidelines said coughs and sneezes can send viruses six feet. Research says sneezes can send droplets 27 feet, and they can lodge in ventilation systems. The guidelines did not consider distances between customers or between them and workers.