Question: The protective suits Teyla & Sheppard put on to keep them from getting infected have a "helmet" piece that does not appear to have an airtight seal; the bottom of the hood just sort of lies on top of the body suit (it's not even tucked in). Is there some way they would be protected from the airborne virus even with what appears to be a very viable opening?
Answer: Those are actually suits that protect from hazardous chemicals. They are cheaper for the prop department and look nearly the same as biohazard suits. A real biohazard suit would indeed have a helmet that seals to the neck.
Grumpy Scot