Oil prices solidified on Friday, and were on track for a third weekly rise in-a-row, fueled by successful coronavirus vaccine trials, while fresh lockdowns in several countries to limit the spread of the virus capped gains.Prospects for efficient coronavirus vaccines and hopes OPEC and its allies will keep production in check have strengthened oil markets this week.Brent crude futures gained 28 cents, or 0.6%, at $44.48 a barrel at 1027 GMT.The more active US West Texas Intermediate (WTI) January crude contract increased 17 cents, or 0.4%, to $42.07 a barrel. The WTI contract for December, which expires on Friday, was up 2 cents at $41.76.Both benchmarks have increased more than 4% so far this week.