TOKYO, Dec 4 (Reuters) - Yields on short- to mid-dated Japanese government bonds inched lower on Friday as current dire conditions of the pandemic and concerns about COVID-19 vaccine supply clouded risk sentiment. Benchmark 10-year JGB futures rose 0.01 point to 151.98, with a trading volume of 18,047 lots, while the 10-year JGB yield fell half-a-basis point to 0.015%. At the shorter end of the curve, the two-year JGB yield and the five-year yield lost half-a -basis point to minus 0.135% and minus 0.110%, respectively. Longer-dated notes moved in the opposite direction, with the 20-year JGB yield and the 30-year JGB yield rising half-a-basis point to 0.390% and 0.650%, respectively. The 40-year JGB yield added 1 basis point to 0.700%. Some investors shifted to safe-haven assets after U.S. drugmaker Pfizer Inc slashed the target for the rollout of its coronavirus vaccine due to challenges in supply chain for the raw materials used in the vaccine. Investors also looked forward to the U.S. employment data due later in the day, a market participant said. (Reporting by Tokyo markets team, Editing by Sherry Jacob-Phillips)