Oil hits its highest since March on Tuesday, increasing towards $47 a barrel, as a third promising coronavirus vaccine encouraged hopes of a faster recovery in economic growth and oil demand next year.AstraZeneca said on Monday its coronavirus shot was 70% effective in trials and could be up to 90% successful, giving the fight in opposition to the pandemic a third vaccine. This follows encouraging results from Pfizer/BioNTech and Moderna.Brent crude climbed 31 cents, or 0.7%, to $46.37 a barrel by 0914 GMT and hit a session high of $46.72, its highest since March 6. US West Intermediate crude increased 32 cents, 0.7%, to $43.38.