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?
Question: Why in season 9 do so many of the episodes follow many of the characters on their days off?
Chosen answer: Probably to broaden the scope of the show's plot and give the audience a chance to see the characters in a different setting, People act differently at home from the way they do at their workplace. By the ninth season, the characters would have become overly familiar and predictable. It gives the writers a chance to do something different with them.
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