A electron microscope image of a coronavirus is seen in this undated picture provided by the Health Protection Agency in London

COMOUT EUO A electron microscope image of a coronavirus is seen in this undated picture provided by the Health Protection Agency in London February 19, 2013. A new virus that emerged in the Middle East last year and has killed five people is well adapted to infecting humans but could potentially be treated with drugs that boost the immune system, scientists said on Tuesday. REUTERS/Health Protection Agency/Handout (BRITAIN – Tags: ANIMALS HEALTH SOCIETY SCIENCE TECHNOLOGY) ATTENTION EDITORS – THIS IMAGE WAS PROVIDED BY A THIRD PARTY. FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS, NO COMMERCIAL OR BOOK SALES. THIS PICTURE IS DISTRIBUTED EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS