(By Salman - iStockAnalyst Writer)Shares of some of the drug makers, medical and health care services, pharma and biotech companies have been holding up quite well despite a broad selloff in equity markets. The primary reason which is being seen as helping these stocks is that they are "recession proof". These companies do not have any exposure in subprime and mortgage market and hence they have emerged as preferred choice for those who aim to build a recession proof portfolio. No matter what happens to the economy, people do fall sick and demand for drugs, antivirals and healthcare services rarely goes down. According to a conservative estimate, growth in healthcare spending is projected to average 6.7% over the period 2007 through 2017.

Foster City, California based Gilead Sciences (NASDAQ: GILD) is a biopharmaceutical company that discovers, develops and commercializes therapeutics to advance the care of patients suffering from life-threatening diseases. Initially the company remained focused primarily on antiviral drugs to treat patients infected with HIV, hepatitis B or influenza. In 2006, Gilead acquired two companies that were developing drugs to treat patients with pulmonary diseases. At a time when Dow Jones Industrial Average and broader S&P 500 are down 17% and 20% respectively on month over month basis, the shares of Gilead Sciences are marginally up, over the same period of time. A couple of weeks back, Gilead Sciences Inc. surprised the market with its earnings for the quarter ended September 30, 2008. Total revenues for the third quarter of 2008 were up 30% at $1.37 billion compared to total revenues of $1.06 billion for the third quarter of 2007. Net income for the third quarter of 2008 was $504.0 million, or $0.52 per diluted share, including after-tax stock-based compensation expense of $30.1 million. Product sales increased 39% to a record $1.34 billion for the third quarter of 2008, compared to $961.9 million in the third quarter of 2007. This growth was primarily driven by Gilead's antiviral products; including the strong growth in sales of recently approved HIV drug Atripla(R) as well as the continued growth of Truvada sales. Atripla sales increased 77 percent to $427.6 million for the third quarter of 2008 from $241.1 million in the third quarter of 2007 while Truvada sales increased 34 percent to $549.1 million for the third quarter of 2008 from $409.1 million in the third quarter of 2007. Apart from a jump in the sales of two drugs, a favorable foreign currency exchange also had a positive impact on net sales.