How Is Your Baby Handling Vaccines?


With increasing public awareness of vaccine reactions, you, the informed parent, want concise and accurate information to help you assess how well your baby is handling vaccination. Severe reactions are rare, but can be easily identified by you and your doctor so you can make a change in your vaccination plan. Moderate side effects, however, are not as obvious. It’s important that you work closely with your trusted medical practitioner to monitor how your baby is handling vaccines.

Common Mild Reactions

First, understand what the typical, and probably harmless, reactions are. These you generally do not have to worry about:

Mild to moderate fever (99 to 102 degrees): This is somewhat expected as the immune system responds to the vaccine.

Mild to moderate fussiness: The pain from the injection and mild internal irritation from the vaccine is expected to cause some crying which is consolable on and off for the rest of the day.

Redness and swelling: This is also expected at the injection site; typically about half of the front area of the thigh or side of the shoulder may turn red and swell, then subside in the next day or two. A small nodule may persist for a few months.

Sleepiness and decreased appetite: A baby may take longer naps or sleep on and off the rest of the day. He or she may be less interested in feeding but should still take in some nourishment.

Moderate Reactions That Should Raise Concern

Some babies will suffer a more extreme version of the above side effects for more than just a day as the immune system over-reacts to the vaccines, causing significant internal inflammation which prompts the body’s nervous, intestinal, and muscular systems to become temporarily irritated and dysfunctional. While such reactions may not cause immediate or obvious harm, they can negatively affect your infant’s overall health, particularly when repeated over and over with subsequent rounds of vaccines. What might such reactions look like?

High fever: Fever of 105 or greater is considered a serious reaction and a valid reason not to repeat that vaccine. Fevers between 102 and 104 that last more than a couple days may also indicate an over-reactive immune response.

Extreme irritability or inconsolable crying for hours: Non-stop intense crying for three or more hours after one or more vaccines is considered a potentially-harmful reaction called encephalitis (inflammation of the brain). Unusual irritability or crying on and off for more than 48 hours may also be a concern.

Severe swelling or whole-body rashes: Swelling of an entire limb or sudden rashes around the whole body may be an allergic reaction that can worsen with repeated doses.

Lethargy and refusal to feed: Lethargy is when a baby is unresponsive to your voice or touch, won’t engage with eye contact, and lies limply in your arms with little movement. Complete refusal to feed for more than a day is also a sign of a potentially serious problem.

Many parents relate that their babies undergo such changes for several days after vaccines. They also witness their baby’s mood and demeanor alter dramatically; the child shuts down, then seemingly recovers and is back to his or her normal self after about a week. Are these responses truly harmless, or do they indicate that your baby isn’t handling vaccines well? Don’t expect your doctor to be able to assess such reactions over the phone; you must communicate your concerns and allow your doctor to evaluate your baby in person.

Infants who are handling the vaccination process may continue, but those who are reacting poorly should assess the ongoing risks versus the benefits. You may delay vaccines, space them out more, or stop further vaccines altogether. If there is any indication that a baby isn’t handling vaccines, work closely with your trusted medical practitioner to decide the best course for your baby’s ongoing medical care.

Asking questions doesn’t make you anti-vaccination . . . it makes you pro-immunity education.