Ah, winter — a time for holiday cheer, sweater weather (well — for San Diego, at least sometimes) and … the flu. Most of us have experienced this nasty virus at least once, and last season’s strain made headlines for infecting even those who were vaccinated, and for its effects on children. To help parents prep for this year and guard their kiddos as much as possible, we connected with John Bradley, M.D., director of the Division of Infectious Diseases at Rady Children’s Hospital-San Diego and a professor and chief for the Division of Infectious Diseases within the Department of Pediatrics at University of California San Diego School of Medicine.

Q: What do we know about this year’s flu?

A: Mother Nature is always surprising us. Flu season can start off with lots of severe cases and then ease up, or can start slow and build to a really bad season like we experienced last year. Influenza mutates easily during a season. We can have more aggressive strains emerge during the season, or we can have influenza adapt so the vaccine is not as effective for the newly mutated strains that can emerge. But you can be sure that we at Rady Children’s, in collaboration with our San Diego County Health Department, are keeping a close eye on this virus!

Q: Last year’s flu vaccine was less broadly effective than is typical. Why was that the case, and do we anticipate this year’s being more effective?

A: As the vaccine was being developed and tested, it looked like it should have worked quite well. It still did, just not as well as we had expected.  While the Centers for Disease Control and Prevention (CDC) is still looking for a specific reason for last year’s decreased effectiveness at preventing serious illness, the answer may lie in what we know from past years.

Although blood tests — the standard way to measure the body’s response to the vaccine — may show that a particular year’s vaccine is protective, an influenza virus that has even slightly mutated compared to the vaccine strain may be better equipped to cause illness. More sophisticated white blood cell response tests are more accurate, but far less routine than blood assessments. Therefore, it’s very possible for a slight variation in the virus to not show up in typical tests.

Q: Who in the pediatric population should get a flu shot? Are there any specific personal factors, such as a particular illness or age range, that would recommend a child not getting a shot?

A: Flu shots should be given to virtually all children over 6 months, since younger babies don’t seem to respond to the vaccine. Even if a child has an underlying illness that may limit their response, any at all will make the infection milder if they still get sick. Generally, and particularly for kids with conditions such as asthma, the vaccine can be life-saving. Sadly, we saw an example of this last year, as most flu-related deaths in the United States were in children who did not receive the vaccine.

Q: How many fatalities each year does the flu cause in children?

A: Flu-associated deaths in children became a nationally notifiable condition in 2004. In the 2017 – 2018 season, 180 children died. That was the highest number of recorded flu-related deaths since reporting began, except during the “swine flu” epidemic. We also know that the fatality rate for children under 2 is as high as the rate for older adults.

Q: What should parents do if they suspect their child has the flu? What would require a visit to the emergency room or urgent care, as opposed to seeing a pediatrician or waiting things out?

A: Most children who get flu are pretty sick. However, if your child begins to act sicker than you would expect (e.g., higher fever, persistent vomiting and unable to tolerate juices and fluids, difficulty breathing) you should take your child to see your doctor. If they get sicker in the evening or at night, take them to an urgent care center or to the Rady Children’s Emergency Department. We have rapid tests that can diagnose flu and blood tests to figure out just how sick your child is. For those who need intravenous fluids, hospitalization will be recommended, but for kids who are able to take liquids, carry on a conversation, and play with toys and video games, providers will typically send them home, often with Tamiflu® treatment.

Q: What treatments are ideal for kids facing the flu?

A: Tamiflu® is the only oral medicine that is active against influenza, and it comes as pills or liquid suspension.  It was first approved for children by the Food and Drug Administration (FDA) more than 15 years ago.  The CDC continuously tests the flu virus each year to make sure that the medication remains active against the virus, and last year, it continued to perform very well during the entire season.

The medicine works by preventing the infected mucous membranes in the nose, throat and lungs from releasing newly made virus within the child’s mucous membrane cells, so it actually takes a few days before you will notice a difference. It is not a “rescue treatment” for the membranes already infected. It is also important to keep in mind that since most flu infections last between five and seven days, if you bring your child to the doctor between three and five days and they are not unusually ill, your doctor may not provide Tamiflu® as the child is likely to be “turning the corner.” For children who are getting worse at that point, though, treatment is likely to help.  However, we don’t know exactly how much, because determining studies were never performed in children.

Although they are still being tested for FDA approval in adult patients with no studies yet in children, there are some newer medicines for influenza that will eventually be assessed at Rady Children’s. If shown to be safe and effective, treatments like these will provide a wider array of options should the flu virus ever become resistant to Tamiflu®.