* Dollar falls to new 2-1/2-year low * Euro, Swiss franc headed for best week in a month * U.S. November jobs data disappoints * Graphic: World FX rates in 2020 tmsnrt.rs/2RBWI5E (Recasts, adds new comment, U.S. data, FX table, updates prices, changes byline, dateline; previous LONDON) By Gertrude Chavez-Dreyfuss NEW YORK, Dec 4 (Reuters) - The dollar fell to a fresh 2-1/2-year low on Friday, on track for its worst week in a month, as investors shrugged off a U.S. non-farm payrolls report that badly missed expectations in November and focused on a flurry of positive vaccine news. Upbeat announcements on vaccinations have helped drive a rally in riskier currencies, while actions taken by the Federal Reserve have weakened the greenback. The euro and Swiss franc, in contrast, were headed for their best week against the dollar in a month. The single currency touched a new 2-1/2-year high, while the Swiss franc rose to its highest in nearly six years. Data showed that U.S. non-farm payrolls increased by 245,000 jobs last month after rising by 610,000 in October. That was the smallest gain since the jobs recovery started in May. But "the vaccines, the restart of talks about stimulus and the new administration, and a less confrontational international background, are still going to be the themes that drive the market," said Marvin Loh, senior global macro strategist, at State Street Global Markets in Boston. In mid-morning trading, the dollar index fell 0.2% to 90.513 , after earlier falling to 90.471, the lowest in more than 2-1/2 years. On the week, the index was down 1.4%, its largest week loss since early November. "It has been another bad week for the US dollar," analysts at MUFG said in a note. "It will encourage speculators to rebuild short U.S. dollar positions which have been pared in recent months." The euro has been one of the biggest winners from recent dollar weakness, breaking decisively above $1.20 this week The single currency hit a two-and-a-half-year high of $1.2177, just above the previous day"s benchmark and was last up 0.1% at $1.2161. Against the Swiss franc, the dollar continued its descent, dropping to a nearly six-year low of 0.8886 franc. The greenback was last down 0.2% at 0.8897. The dollar though gained 0.2% against the yen at 104.02 yen. Ulas Akincilar, head of trading at the online trading platform, INFINOX, said that despite the weaker-than-expected U.S. employment data, it was a "finely balanced jobs report." "The calculation is that the slowing jobs market will spur U.S. lawmakers into agreeing a fiscal stimulus to match the Fed"s monetary support. And yet the slowdown is not so bad as to send investors running for the hills," he added. Sterling, meanwhile, rose 0.5% against the dollar to $1.3514 , helped by the greenback"s broad weakness. It hit a 2-1/2-year peak versus the greenback on expectations that Britain will be able to clinch a post-Brexit trade deal with the European Union. ======================================================== Currency bid prices at 10:20AM (1520 GMT) Description RIC Last U.S. Close Pct Change YTD Pct High Bid Low Bid Previous Change Session Dollar index 90.6180 90.6930 -0.07% +0.00% +90.7670 +90.4710 Euro/Dollar $1.2149 $1.2145 +0.03% +8.37% +1.2177 +1.2132 Dollar/Yen 104.1450 103.9000 +0.25% -4.11% +104.1500 +103.7800 Euro/Yen 126.51 126.11 +0.32% +3.74% +126.6700 +126.0500 Dollar/Swiss 0.8900 0.8910 -0.10% -8.02% +0.8917 +0.8886 Sterling/Dollar 1.3505 1.3448 +0.43% +1.83% +1.3538 +1.3409 Dollar/Canadian 1.2809 1.2864 -0.43% -1.40% +1.2873 +1.2805 Aussie/Dollar 0.7431 0.7442 -0.13% +5.91% +0.7443 +0.7410 Euro/Swiss 1.0811 1.0818 -0.06% -0.38% +1.0848 +1.0811 Euro/Sterling 0.8994 0.9026 -0.35% +6.39% +0.9067 +0.8984 NZ 0.7046 0.7078 -0.44% +4.73% +0.7079 +0.7028 Dollar/Dollar Dollar/Norway 8.7770 8.7370 +0.31% -0.09% +8.7975 +8.7480 Euro/Norway 10.6638 10.6288 +0.33% +8.40% +10.6826 +10.6182 Dollar/Sweden 8.4487 8.4256 +0.10% -9.61% +8.4578 +8.4190 Euro/Sweden 10.2642 10.2539 +0.10% -1.96% +10.2820 +10.2440 (Reporting by Gertrude Chavez-Dreyfuss; Additional reporting by by Herb Lash in New York and Iain Withers in London; Editing by