Calicivirus vaccine can cause certain side effects. Joint pain and weakness in the feline is quite common. The side effects remain for around 2-3 weeks after vaccination. Some cats are also studied to have high fever after vaccination. Intranasal vaccines can cause symptoms like sneezing and having eyes discharge. These mild respiratory problems are not serious at all. However, this can cause some amount of discomfort in the cat. A very and rarely seen serious side effect of calicivirus vaccine is fibrosarcoma. Sometimes, calicivirus vaccination fail and the cats who have taken vaccination also may have the risk from this virus. Apart from this, some common side effects that are seen are depression in kittens and allergic reactions in grownups. Pain and swelling are very common for some two weeks in cats who have taken vaccine for calicivirus. In some cats, the reaction can be some sort of autoimmune disease or disorder. Looking into these side effects, before vaccinating your cat or kitten, it is necessary to talk to the vet and then take the decision. Sometimes, side effects and reactions to the vaccine for calicivirus can be dangerous and can be responsible for many complications. But every case is different and thus, it is apt to consult the vet first.