Looking for a defensive position in today’s shaky economy? Giliad Sciences (GILD) could be a safe play, says Connor Browne, co-portfolio manager and managing director at Thornburg Investment Management.

It’s unfortunate, but the number of people with HIV is increasing around the world.  Thankfully, many patients can live much longer, healthier lives with advances in medicine from pharmaceutical and biotechnology companies like Giliad Sciences.

“Unfortunately, the patient share is growing. But, fortunately, if they take these drugs they can live decades,” says Browne.

Why Giliad, specifically? Giliad sells the backbone components of the HIV/AIDS “cocktail,” or mixture of drugs, says Browne.

The company, says Browne, is a consistent earner because it has a very predictable revenue and earnings stream.  And it has a leading and growing share in the HIV drug market, which is, unfortunately, becoming a larger market each year.

Giliad’s year-over-year earnings are up 40% right now, he says, and its HIV business is up 20%.

The company is also not much higher than the market multiple, about 15 times 2010 earnings today, making it seem like a great value given the growth, he added.

 And Giliad continues to work on improving the treatment of HIV.  One such treatment, according to Browne, is called the quad-combo pill now in trials, which could be an improvement for patients.

Asked if a future vaccine against HIV would hurt the company, Browne says, there’s already one vaccine in testing that researchers were able to show gives a 30% lower risk of infection in those who had it, which is good news.  However, he adds, even if a vaccine was created that prevented 100% of infections, which is a long way off, the existing patient population would likely still need treatment.

GlaxoSmithKline (GSK) and Merck (MRK) are two large competitors to Giliad, says the portfolio manager.  And though they have some promising newer treatments, a lot of competitors are using drugs from Giliad in combination with them.

So, who is this an ideal investment for?  Browne considers Giliad a generally defensive stock.  “When people are worried about recession, this should hold up well.”  But there are risks, he notes, since this is exposure to just one market.  If something happened like finding a safety problem with a drug, the stock could go down a lot, he warns.  Browne suggests investing with professionals to ensure investors get diversity in their stock holdings.

The Thornburg Value Fund (TVAFX) is a large-blend, value fund with $3.5 billion in assets under management.  Giliad makes up roughly 3% of the fund’s holdings, while pharmaceuticals and biotechnology companies make up about 9%.