Only live attenuated vaccines can still cause infection. All vaccines vaccines can cause illness, but this is commonly a hypersensitivity reaction (similar to an allergic response), not due to the disease itself. Very rarely a serious disease known as [[eczema vaccinatum]] can emerge. Vaccines that use pieces of pathogens often use a [[carrier virus]] in the injection. Those with very weak immune systems that are exposed to such a vaccine can become infected with the carrier virus and develop [[eczema]]. A recent case of this was reported in the United States after a military man was vaccinated with small pox and his two year old son became ill. <ref> http://www.associatedcontent.com/article/183349/soldier_infects_toddler_son_with_lifethreatening.html AP article on eczema vaccinatum </ref> | Only live attenuated vaccines can still cause infection. All vaccines vaccines can cause illness, but this is commonly a hypersensitivity reaction (similar to an allergic response), not due to the disease itself. Very rarely a serious disease known as [[eczema vaccinatum]] can emerge. Vaccines that use pieces of pathogens often use a [[carrier virus]] in the injection. Those with very weak immune systems that are exposed to such a vaccine can become infected with the carrier virus and develop [[eczema]]. A recent case of this was reported in the United States after a military man was vaccinated with small pox and his two year old son became ill. <ref> http://www.associatedcontent.com/article/183349/soldier_infects_toddler_son_with_lifethreatening.html AP article on eczema vaccinatum </ref> |