SINGAPORE, Oct 8 (Reuters) - Singapore is working on allowing quarantine-free entry to travelers from the United States who are vaccinated against COVID-19 before the end of the year, its minister for trade and industry said on Thursday. Singapore, a travel and tourism hub, began a similar programme for travellers from Germany and Brunei last month as part of a gradual easing of its COVID-19 border controls. "We have had successful pilots of Vaccinated Travel Lanes (VTL) with Germany and Brunei to facilitate the entry of fully vaccinated individuals into Singapore for business and leisure," said Gan Kim Yong said in a speech during a visit to Washington DC. "We are now working on a VTL with the U.S. as soon as possible, and certainly before the end of the year."Vaccinated visitors in the VTL can bypass the isolation requirements if they test negative in polymerase chain reaction tests.