Fig. 1From: Combination therapy of zinc and trimethoprim inhibits infection of influenza A virus in chick embryoSchematic diagram showing study protocol. Test material were injected 6Â days after start of egg incubation, Hamburger and Hamilton stage 29. An hour later, the virus was injected into the allantoic space. Eggs were returned to the incubator, between injections. It was candled daily for 7Â days afterward to determine embryo survival, then discardedBack to article page