Side Effects of Vaccines in 4-Year-Olds

Nearly every parent has experienced the emotional turmoil that comes when their child needs a vaccination. Sometimes the discomfort doesn’t stop when the needle is withdrawn. Children can experience a number of side effects from routine vaccinations, such as a low fever and soreness. Between the ages of 4 and 6 years, children generally receive additional doses of DTaP, MMR, chickenpox and polio, as suggested by the American Academy of Pediatrics 1. Side effects associated with vaccines are generally mild, and the health risks almost always outweigh the temporary side effects.


DTaP is an abbreviation for diphtheria-acellular pertussis-tetanus. This vaccine protects children against pertussis, also known as whopping cough, which wreaks havoc on the respiratory mucus membrane. Most parents recognize mild side effects after the DTaP vaccination, such as:

  • irritability
  • fever
  • loss of appetite
  • fatigue
  • slight swelling or redness at the injection site

More severe but rare side effects include inconsolable crying after receiving the vaccine, as well as seizures. A physician should be notified if this happens.


MMR is a combined vaccine, consisting of measles, mumps and rubella. These diseases, which are caused by viruses, can lead to significant illness. Possible side effects caused by the MMR vaccine include fever, rash, mild joint pain, febrile seizures and swollen cheeks. Parents should watch for signs of prolonged fever or unusual behaviors, and contact the child’s pediatrician if the side effects become too severe.


A second dose of the chickenpox vaccine, or varicella, is recommended by the American Academy of Pediatrics for children between the ages of 4 and 6. Minor side effects associated with the chickenpox vaccine include mild redness or tenderness of the injection site, fatigue, fever and illness similar to varicella. Some children experience a rash for up to one month after the vaccination is administered. Serious side effects, such as allergic reactions or febrile seizures, are rare.


The high-potency inactivated polio vaccine prevents polio, a viral illness that can result in permanent paralysis. Side effects of the polio vaccination include mild soreness or redness of the injection site. Parents can give some relief by patting the injection site area with a cool, wet cloth. Allergic reactions are rare with the polio vaccine.

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