Changes in Availability of ENDS: 2019–2020, U.S

Introduction: Events during 2019 and 2020, such as the outbreak of e-cigarette, or vaping, product use‒associated lung injury; manufacturer product withdrawals; federal regulations; and coronavirus disease 2019, potentially affected the retail availability of ENDS in the U.S. Measuring changes in ENDS availability informs the understanding of the ENDS marketplace and contextualizes sales trends. Methods: Joinpoint regression was used to estimate slope changes in the number of available ENDS in 2019 and 2020 and considered correspondence with tobacco marketplace events. Availability, the weekly number of unique universal product codes with nonzero sales, was derived from NielsenIQ scanner data. U.S. ENDS availability was modeled overall and by subproduct and flavor category within subproduct: mint, menthol, tobacco flavored, and undetermined. Results: ENDS availability increased by 66% from January 2019 to December 2020. Availability decreased by 43% among prefilled cartridges and increased by 511% among disposables, both led by flavored varieties. During January 2020–February 2020, prefilled cartridge availability decreased by 23.71 universal product codes per week. During July 2020–August 2020, disposable availability increased by 27.90 universal product codes per week, led by flavored products. Conclusions: ENDS availability increased during 2019 through 2020, led by a rise in flavored disposables. Multiple slope changes in ENDS availability occurred, many coinciding with tobacco marketplace events. The slope of ENDS explicitly prioritized for federal enforcement (i.e., flavored prefilled cartridges) notably decreased in early 2020 and, soon thereafter, the slope of ENDS not explicitly prioritized for enforcement (e.g., flavored disposables) notably increased, suggesting an association with U.S. Food and Drug Administration's prioritized enforcement guidance.