 [ Symptoms ] last year my husband got his h1n1 shot and was very sick for three days is it safe to get this year is flu shot [ Disease ] if you are referring to cheratussin ac that is a prescription product and it should not be given to anyone other than the person for whom it was prescribed if it was prescribed for your 4 year old it is safe as long as it was prescribed at the proper dose your pharmacist should check the dose for your child when processing your prescription