For the second week in a row, a major drug company shocked Wall Street. Chiron (nasdaq: CHIR - news - people ) announced it would not supply any influenza vaccine for the upcoming flu season. The previous week, Merck (nyse: MRK - news - people ) shocked investors when it pulled marquee drug Vioxx off the market due to heart attack risks. Does bad news come in threes? Pharmaceutical and biotechnology shares have been pounded since early September; the American Stock Exchange Pharmaceutical Index was down 4.60% for the week while the Nasdaq Biotechnology Index had a weekly loss of 4.14%.
