** Shares of China's WuXi Biologics 2269.HK fall 5.9% to HK$15.62, on track for their biggest one-day pct drop since Oct 15 if current losses hold
** Stock hits the lowest level since Dec 3 on its second straight session of decline; second-biggest pct loser in the Hang Seng Index .HSI, which slips 0.6%
** Co said on Monday it would sell its vaccine facility in Ireland to U.S. drugmaker Merck & Co MRK.N for about $500 mln, ahead of potential U.S. legislation that would restrict business for Chinese biotech companies
** The U.S. House of Representatives passed the Biosecure Act in September, which would ban federal contracts with targeted firms and their business partners
** The Hang Seng Commerce & Industry Index .HSNC eases 0.8% and the healthcare index .HSCIH declines 0.7%
(Reporting by Donny Kwok)
((donny.kwok@thomsonreuters.com))