Fever and Vaccines: Good or Bad?
Fever is a common side effect of numerous vaccines in children, but is that good or bad? Take this 5-question quiz to decide.
A lot of “heat” can be generated when pediatricians are discussing vaccines with parents hesitant to immunize their children. Fever, medically defined as a temperature >38°C (100.4°F), frightens parents and is usually viewed as something bad that needs to be “brought down” to normal. Fever is a common side effect of many vaccines in the pediatric age range. Is that possibly a good thing?
Take the short, 5-question quiz above to decide.
Question 1: Which of the above vaccines is/was most likely to result in significant fever?
Answer: A. DTP. LYMErix was an effective vaccine approved for use against Lyme disease in the 1990s, but was pulled off the market by the manufacturer due to poor sales and law suits over possible arthritis side effects. Interestingly, a new Lyme disease vaccine is on “fast track” by the FDA, but is only in phase 1 testing. MMR and Prevnar 13 can cause fever in a small percentage of recipients that is usually mild.
Question 2: Which of the above vaccine combinations results in increased fever?
Answer: B. Proquad given at 12-23 months. Recipients of Proquad aged <2 years have been shown to have more fever and febrile convulsions vs children receiving the 2 vaccines in separate shots at the same time.
Question 3: What is the increase in risk of a febrile seizure in a child aged 12 mos receiving Proquad vs the separate MMR and varicella vaccines given the same day at different sites?
Answer: D. A (risk is doubled) and B (risk is about 1 in 2300).
Question 4: Due to this increase risk of simple febrile seizure, the CDC recommends which action be taken in children aged <2 years?
Answer: B. Proquad can be given, but providers should explain the increased risk to parents.
Question 5: After deciding you will let the parents choose if they would rather give their child 3 shots vs 4 at the 12-month well visit by using Proquad, a mother asks, “What is a child's lifetime risk of having a febrile seizure because my child has already had a fever 4 or 5 times?” You tell her the risk is about what?
Answer: A. 1 in 30. If those 2300 children all receive Proquad then, statistically, 78 will have a febrile seizure vs 77 in a similar sized group who get the 2 vaccines separately.
Resources
1. Chen RT, Clark TA, Halperin SA. The yin and yang of paracetamol and paediatric immunisations. Lancet. 2009;374:1305-1306.
2. WHALE: An example of the misinformation sent out by the DPT antivaccine group.
3. Firger J. Lyme disease vaccine on fast track for FDA approval. Newsweek. July 25, 2017. http://www.newsweek.com/lyme-disease-vaccine-valneva-fda-approva-641796. Accessed July 5, 2018.
4. Boyles S. No rise in seizure risk with MMRV booster shot. WebMD. April 2, 2012. https://www.webmd.com/children/vaccines/news/20120402/no-rise-seizure-risk-mmrv-booster-vaccine#1. Accessed July 5, 2018.
5. Shinnar RC. Child Neurology Foundation. http://www.childneurologyfoundation.org/disorders/febrile-seizures/. Accessed July 5, 2018.