Just yesterday, a friend engaged in casual conversation by asking if I was seeing the Flu yet in my office. “Only one confirmed case so far”, I told her. “Well, a few of my friends got the flu after getting the shot this year” she remarked. She anticipated my response – “You can’t get the flu from the flu vaccine!” Year after year, I hear the same comment- from friends, patient parents, acquaintances, the FOX news network (j). What is happening in these cases? Are people really suffering a side effect of the vaccine itself? The influenza vaccine, like all other vaccines, does incite an antibody response. In fact, its effectiveness lies in its ability to stimulate the immune system to produce disease fighting agents that well, may make you feel a little under the weather for a day or two. Low grade fevers, a few muscle aches and some fatigue are normal and fleeting, and honestly a heck of a lot more tolerable than influenza. But what about the people who develop an actual illness post vaccination—an upper respiratory illness characterized by a sore throat, cough, congestion and a fever that runs a typical cold course? Did the flu vaccine precipitate this illness?
Based on how a vaccine works; how it grabs the attention of the immune system and encourages specific antibody production, it seems quite possible that despite its grand complexity, the immune system turns its full attention away from the current enemy to prepare for a future invader. Thus, a common cold develops in a person that was fighting off the illness quite well before being immunized. This theory drives my decision to hold vaccines when one of my patients is acutely ill. It is not that I don’t think they can handle the vaccine if ill, but it may complicate the picture. They will probably feel worse for a day or two after vaccination, which may then cloud parental and even physician judgment with regard to determining whether the illness itself is progressing or is simply a transient effect of vaccination. We can still watch and wait regardless, but when your own child is up all night and they’ve been fighting a cold for a week already and now have a new fever, decreased appetite and increased fussiness… watching and waiting is hard. Unless absolutely necessary, I want to hold off on antibiotics, as do most parents, so if we can give them a little more time to adequately clear their infection before getting vaccines, I am absolutely in favor of it.
What are the actual risks of the flu vaccine as it relates to kids? The CDC states soreness, redness, or swelling at the site of injection, fainting (mainly among adolescents), headache, muscle aches, fever, and nausea. If these problems occur, they usually begin soon after the shot and last 1 to 2 days. Anaphylaxis to a vaccine is exceedingly rare, but if it does happen, it generally occurs within 1-2 minutes of administration, when you are still in your doctor’s office and surrounded by persons equipped to handle such an emergency. A very remote side effect, known as Guillain-Barre has been found to occur in 1-2 people per MILLION vaccinated against the flu. Guillain-Barre causes a progressive weakness and paralysis as the immune system misfires and attacks a person’s own nervous system. The exact etiology of Guillain-Barre is unknown, but can follow random illness or rarely vaccination. I have had a patient develop Guillain-Barre in the last year as a post-viral response. I sent him to Children’s Medical Center upon presentation, where he was effectively treated via IVIG (healthy donor immunoglobulins given via an IV that displace the attacking cells from the nervous system). He now runs full speed down the hall when he comes in to see me! He grins, speaks, and high-fives as effortlessly as he runs.
There is an additional risk worth noting; an increased risk of a febrile seizure (or seizure with fever) in kids who receive the Prevnar (or pneumococcal) vaccine at the same time as the influenza vaccine. Febrile seizures occur quite randomly with fever viruses in the pediatric population, generally between the ages of 6mos and 6years, with no associated long-term complications. But, you may ask yourself – does it make sense to get these two vaccines together? If it is flu season and time for your child’s booster Prevnar vaccine, then the answer is a simple yes. The killer in an influenza infection is often not the flu in and of itself, but rather the superinfection; the secondary pneumonia often caused by invasive streptococcus bacteria. This is the combination that overcomes us. The immune system is busy eradicating the flu virus when the stealthy pneumococcal bacteria slip into the respiratory tree and incite a war. This intruder is often recognized too late by our complex defense system, and a delay in response can prove fatal.
As a resident in the PICU, I witnessed a patient die within this massive storm. As a private practice doc, I have witnessed plenty of febrile seizures, and continue to care for the thriving children who experienced such an event. I would absolutely choose the later if it was an actual choice.
I know it is hard to do anything that may make you feel off for a day or two, but being laid out for a week at best seems a much worse alternative. Building a robust immune response to influenza stems from the introduction of an attenuated form of the virus to our relatively naïve system, so that when we face the real thing, which undoubtedly at some point we will, we can fight the flu in full armor.
