EXHIBIT 4.4 STOCK PURCHASE AGREEMENT THIS STOCK PURCHASE AGREEMENT (the "Agreement") is made as of the 22nd day of January, 1999, by and between VICAL INCORPORATED, a Delaware corporation (the "Company"), and PFIZER INC, a Delaware corporation...Stock Purchase Agreement • May 14th, 1999 • Vical Inc • Biological products, (no disgnostic substances) • California
