A.M.
Do NOT rely on "Airborne". It is just a multi-vitamin. Nothing more. Google "Airborne Settlement" for info on the lawsuit and the results.
Honestly, E.... There's not much you can do. Any time one of you gets sick, the rest are sure to follow. I'm the oldest of 5 kids, and a mother of 4, so I've had -tons- of experience with the cycle of sickness.
Get as much rest as you can. Have hubby clean the house when he gets home instead of trying to do it yourself during the day. Remember... You did the same for him when he was sick, now it's his turn to help you out.
If he gets grumpy about having to do houshold chore after working all day, just remind him that you're sick, pregnant, and trying to deal with two sick kids, so you need to rest as much as you can and that you work all day as well.
Drink lots of fluids (anything you can stomach: soup, juice, water, milk) and have your little ones do the same. Chicken soup really does work to help shorten sick times and, though homemade soup works best, canned soup works a little bit as well.
Here's hoping that you only have to endure one cycle of everybody sick at once. (I once had a 9 month stretch where everybody passed the flu around... one person at a time. Nothing kept it away from the other kids or me.)
Good luck and well wishes,
A.