FA16 Immunization Module’s Updates
Adverse Reactions to Vaccines
Vaccine reactions, or "vaccine side effects," can be classified as local, systemic, or allergic, generally increasing in severity respectively.
Examples of local reactions include pain, swelling, or redness at the site of the reaction. These most commonly occur with inactivated vaccines like DTaP. One specific type of local reaction is named the Arthus reaction, and is the result of an antibody response to the injection. This requires that antibodies had already been produced during prior exposure to the vaccine and is mainly seen in toxoid vaccines like Diptheria and Tetanus.
Systemic reactions include many of the symptoms associated with a systemic immune response, including fever, malaise, myalgia, headache and loss of apetite. Though possible with any whole cell vaccine, they are most common following live attenuated vaccines such as a nasally administered influenza vaccine.
Allergic reactions to a vaccine can be to the antigen itself, or any other ingredient within the vaccine. Though rare, they can be life-threatening in severity.
Interestingly, a "vaccine event" is distingished from a vaccine reaction in that it is any event following a vaccination, whether a true adverse reaction or a coincidental occurance. For instance, guidelines for instating permanent DTaP precautions in a pediatric patient include:
- Temperature of 105°F or higher within 48 hours of a dose of DTaP
- Collapse or shock-like state within 48 hours of a dose of DTaP
- Persistent inconsolable crying lasting 3 or more hours occurring within 48 hours of a dose of DTaP
- Seizure, with or without fever, occurring within 3 days of a dose of DTaP.
Sources:
GeneralRulesImmunizationCDC
"Immunization - You call the shots" from CDC.gov
@Spencer Printen. I read about some of these adverse reactions to DTaP for my post on vaccine safety. I didn't include this in my post but there was an experiment where they compared combined diphtheria, pertussis, and tetanus vaccine against diphtheria and pertussis vaccine and found the frequency of severe reactions was greater in DTaP vs DTa. They suspect that the pertussis component is therefore responsible for the severe reactions in DTaP. I am not entirely sure why.
World Health Organization (WHO). Information Sheet Observed Rate of Vaccine Reactions Diphtheria, Pertussis, Tetanus Vaccines. May 2014. http://www.who.int/vaccine_safety/initiative/tools/vaccinfosheets/en/
@Spencer Printen. Good post, maybe your classmates can help you determine which part of the DTaP vaccine is most likely to cause these reactions. There is some history here which is highly relevant to this post.
I've been very impressed with the CDC and their attenuation to adverse reactions. They have two websites: first one has a great listing for all the different vaccines, their adverse reactions, and the reported frequency of those reactions (http://www.cdc.gov/vaccines/vac-gen/side-effects.htm). The second is a website where you can actually go and report an adverse reaction to a vaccine, called the VAERS (http://www.cdc.gov/vaccinesafety/ensuringsafety/monitoring/vaers/).