Biotech stocks advanced in the week ending May 22, defying the broader market retreat. The defensive nature of the industry and stock-specific moves lent support.

The spread of the monkey pox virus in the U.S. and Europe sparked a rally in companies working on vaccine candidates against viruses.GeoVax Labs, Inc.(NASDAQ:GOVX) was the biggest beneficiary, with its stock more than doubling in the week.

NanoViricides, Inc.(NYSE:NNVC) also advanced strongly following positive clinical updates provided by the company.

On the regulatory front,Sanofi(NASDAQ:SNY)-Regeneron Pharmaceuticals, Inc.(NASDAQ:REGN) received the Food and Drug Administration...