Bucks County Health Improvement Partnership

What to Expect When Your Child Is Vaccinated

Bucks County Health Improvement Partnership

Vaccines are an important part of fighting childhood diseases. Since the beginning of widespread vaccinations, many childhood diseases have become extremely rare, saving many children’s lives. But the germs are still out there. It’s important for children to continue to be vaccinated so that they do not contract these serious illnesses, such as measles, polio, and diphtheria.

Vaccines work by stimulating the body to create antibodies to a virus (or bacterium), thus giving the body a weapon to prevent infection with the disease. These antibodies are stimulated by introducing a dead or extremely weakened virus (or portion of a virus), which turns on your child’s immune system to fight off the invaders. Since the amount of the illness is very small, your child is very unlikely to become sick from the vaccine, but there could be some mild reactions to the virus. This is normal and should be expected.

Normal reactions to vaccines

Symptoms generally appear within 12-48 hours after being vaccinated. Common reactions to vaccines in children include:

  • Swelling, redness, or pain around the area of the shot
  • Fever
  • Mild rash
  • Sleepiness
  • Fussiness
  • Decreased appetite

These symptoms are normal and are generally considered a sign that the vaccine is working, because they show that your child’s immune system is trying to fight off the weakened or dead virus that has been introduced. However, these symptoms are still uncomfortable, and you may wish to ease your child’s discomfort.

Making your child more comfortable

We do not recommend painkillers or fever reducers for a fever under 102, because these medications may slow down your child’s immune response, thus lessening the effectiveness of the vaccine. However, you can make your child more comfortable:

  • Gently and lightly massage the injection site three times a day or as needed to stimulate movement of the blood away from the area
  • Apply a compress for about 10 minutes at a time – a warm compress increases blood flow, which could move the blood away from the area, but a cool (not cold) compress can be used if it makes your child more comfortable
  • If the area of the shot is itchy or if the child develops a mild rash, apply a 1% hydrocortisone cream several times a day as needed
  • Make sure your child remains well hydrated, especially infants, who may still be nursing. Children may enjoy ice pops or some other hydrating treat that is age-appropriate
  • If your child’s fever is over 102 degrees, you may use acetaminophen to reduce the fever and ease discomfort

When you should seek help

Severe reactions are very rare, but you should watch your child for any of the following and call your doctor if he or she develops these symptoms:

  • Redness becomes larger than two inches, becomes more painful after several days, or lasts more than a week
  • Fever begins after two days or lasts more than three days
  • Your child becomes worse rather than better or has extreme discomfort
  • Your child is having any difficulty breathing
  • Your child develops a rash that seems serious to you
  • You are concerned and believe your child needs to be seen 

As medical professionals, we respect parents’ instincts, so if you are concerned, call your doctor. However, be assured that serious reactions are very rare. The benefits of these childhood vaccinations have been demonstrated by the dramatic decrease in death and disability caused by these diseases since vaccines were introduced.


Your email address will not be published. Required fields are marked *