Vaccination required All participants must receive COVID-19 vaccines before the event. The Department of Public Health may limit the number of participants in large-scale events. Registrants will be notified of their decision as soon as the Littleton Rotary Club receives word, the press release said. The Appleman Triathlon is returning following last year's cancellation due to the pandemic. The event was among several athletic competitions and community events cancelled or postponed for COVID-related reasons. More details and a sign-up link are available on the Appleman Triathlon website. Changes in rules Gov. Charlie Baker announced on April 26 plans for easing masks restrictions and other measures.