Can a sick child be vaccinated?

Question 10 of A Parent’s Guide to Vaccines : A Conversation About Vaccines for New Parents

Before administering a vaccination, the doctor, nurse, or medical assistant takes your child’s temperature and asks if they are sick. Why is this done?

The answer is very simple: If your child is sick, you may need to consider postponing the vaccination until they have recovered.

According to the CDC, your child can have most vaccines if he or she is only mildly ill, but “children with moderate or serious illness—with or without fever—may need to wait until they are better to get some vaccines.”

CDC guidelines to determine if you should postpone your child’s vaccine because of illness:


You don’t usually need to postpone if your child:

  • Has a mild illness
  • Is taking antibiotics for a minor illness

You may want to postpone if your child:

  • Has a moderate to severe illness
  • Is taking an antiviral

However, if your child is sick at all, the CDC says that you may want to wait until they recover before administering the MMR, Td, Tdap, or Pneumococcal (PCV13).

3 reasons why you may want to postpone all vaccines until your child is completely healthy:

  • 1. The difference between a mild and moderate illness can be hard to differentiate.For example, Influenza B is considered a mild illness, but Influenza A is considered a moderate one. The difference between these diseases can only be confirmed through laboratory testing.The difference between a mild, moderate, and severe illness often depends on the patient’s health or stage of infection. A pathogen can cause mild illness in some, and severe illness in others, depending on the health of the individual. Also, many types of bacteria are carried as normal flora, and can become opportunistic pathogens depending on the health of the individual.
  • 2. Vaccine safety and efficacy trials are not performed on people who are sick. Pre-licensing safety testing for vaccines includes only healthy individuals. No prospective clinical data exists showing how sick children respond to vaccination.Safety surveillance on this population is performed retroactively through the Vaccine Adverse Event Reporting System (VAERS), but underreporting via this passive surveillance system may distort findings. Effectiveness may also be an issue when vaccinating a sick child. If your child is busy fighting one infection, their immune system may not build the antibodies necessary to protect them from the infection they are being immunized against, leaving them vulnerable to vaccine-preventable diseases in the future.
  • 3. If your child receives a vaccine while they are sick with a virus there is a possibility for the pathogen to enter the central nervous system and cause severe, life-threatening illness.The nervous system is well insulated against most infections, but when its natural defenses are compromised, it can be vulnerable to viral infection of the central nervous system (CNS).Injury to the muscle is one way that the nervous system can become compromised because skeletal muscle tissue is innervated with peripheral nerve cells. Examples of muscle injuries include animal bites, deep cuts, and puncture wounds from immunizations. Once inside injured muscle tissue, viruses can travel into the peripheral nerves. “A number of important human viruses spread through the axons of peripheral nerves and are thus carried to the CNS,” (Rudolph, 2011, p. 884).

Wrapping it up

Muscle injury caused by a vaccine needle is one important reason to postpone vaccination during illness. Another is that the immune systems of moderately to severely sick children might not react appropriately to immunizations. It is the responsibility of every parent to weigh all risks and benefits before consenting to any medical intervention because you are the most important health advocate your child has.

When it comes to vaccination, the benefits of waiting until your child feels completely well may help you to avoid the many risks involved with immunizing during any illness.

  • 11_3_15 red plane square

    Return to A Parent’s Guide to Vaccines

    Navigate pediatric immunizations – Inspired by a first time mom

    read more

Stay Informed. . . Stay Healthy!

Join the Conversation

your thoughts matter




Wow, suddenly it is the parent’s responsibility? With all the legislative push for mandated, mandatory, banning from day care, preschool and school it seems parents have no say whatsoever, but this is our responsibility? So doctors aren’t trained to not vaccinate sick kids? Apparently not since it has become a vaccinate at all costs scenario, with no options, and no postponing. You say that one reason is vaccines are not tested on sick kids, yet they have not been tested on pregnant women either but that isn’t stopping anyone from now vaccinating pregnant women! Wow, the hypocrisy of it all is mindblowing.

Taylor Anderson

Is it too hard to come back after your child isn’t sick anymore? Additionally, sick people have weakened immune systems. Mildly sick patients, who can get vaccines safely, have a similar immune system to pregnant women (except that pregnant women’s immune systems are weakened less). To put it simply, it is safe for pregnant women and mildly sick patients to vaccinate. Third, you are allowed to postpone and decline vaccinations in almost all circumstances. My mother, for example, did not vaccinate me from since I was 4 until I left her house and did not have to do so because, for her, it was against her religion. Parents are NOT thrown to the dogs when it comes to vaccinating children. You have choices and it is not only the parent’s responsibility. It is saying to postpone your vaccinations if your child is moderately or severely sick and doctors ask patients if the child is sick. Before, you are upset about having no options, apparently. Now, you are upset that you get responsibility, which is noticing if your child is moderately to severely sick. (To put it in perspective, a fever of 101 is still considered mildly sick and it is safe to vaccinate.) Since that responsibility is too difficult, did you want a personal assistant to follow you around to know when your child is sick?

Pedro Mem

This page includes information on who should and shouldn’t get an influenza vaccine, and who should talk to their doctor or other health care professional before vaccination. Talk to your doctor or nurse if you have any questions regarding which influenza vaccines are best for you and your family.

Happy New Year!

Lisa Judge

I’m sorry but if there are no current studies on how people react when getting vaccinate when sick, how can they say a mild sickness is okay?

Ernest Abankroh

If one is so k of say Corona viruse, is it advisable to be vaccinated of a Corona virus vaccine (assuming there is an efficacious vac one for it)?


Join the Conversation

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