SAN DIEGO, April 27, 2010 (GLOBE NEWSWIRE) -- Vical Incorporated (Nasdaq:VICL) announced today that a prime-boost malaria vaccine regimen provided sterile protection, with no disease symptoms and no detectable malaria parasites, in 4 of 15 vaccinated volunteers a full 28 days after challenge with multiple infected-mosquito bites. The remaining 11 vaccinated volunteers and all 6 unvaccinated control volunteers developed parasitic infections.