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Why The Flu Is Killing Healthy Kids and What You Can Do About It

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In recent flu seasons, the death toll among healthy kids caught everyone’s attention. The Centers for Disease Control and Prevention (CDC) notes that the majority of deaths from the flu were among children who had not been vaccinated and were otherwise healthy.

A flu shot is more important than ever during the 2020-21 season. While we may not be able to control COVID-19 as much as we would like to, we can help control co-infection--or getting the flu and COVID-19 at the same time. This can be very dangerous. It's important to schedule your child's (and every family member's) flu shot early in the season.

How Viruses Affect the Immune System

To understand what makes the flu so deadly and what you can do to protect your family, it’s important to first know how viruses affect the immune system.

When a virus like influenza (flu) gets into a body’s cells, it inserts its own DNA into those cells and programs them to replicate the virus, allowing it to spread to other cells.

Our immune system, similar to the military, has various techniques and weaponry to kill viruses and bacteria. One such weapon is a “search and destroy” team. When the immune cells detect a bacteria or infected cell, they set into motion a chemical response throughout the body that leads to that infected cell’s death. Raising the temperature of the body (a fever) is part of that response and makes it harder for a virus or bacteria to survive. The activated immune cell team will destroy a virus in three to five days, on average.

Why Are Healthy Kids Dying of the Flu?

The healthier and stronger the person, typically the stronger and more robust their immune military. Since the flu moves fast, a strong immune system will use its biggest bombs against the flu-infected cells. But a robust immune system can also go into overdrive, known as a “cytokine storm,” where the body-wide activation causes this tissue damage on a large scale. This wide-spread immune system attack can cause deadly problems like pneumonia, leaky blood vessels that result in dangerously low blood pressure, and even meningitis due to the breakdown of the barrier between the blood and the brain.

If your child starts to get better, then suddenly worsens, it may be a sign of a secondary infection requiring medical care. You should also call a doctor if your child experiences a high fever that lasts for more than four days or that goes away and then comes back, sustained rapid breathing, rapid heartbeat, or significant tiredness or dizziness.

Preventing a Dangerous Immune Response

Ideally, we want the immune system to destroy the virus before it has a chance to spread throughout the body and trigger such an overwhelming response. If the immune system knows ahead of time to watch for influenza, it can kill off the virus before it invades the cells, reducing the number of cells affected and thereby decreasing the overall impact of the flu.

So how can we prime our immune system to watch for the flu virus? This is where the flu shot comes in.

Cell Memory: Why the Flu Shot Works

We wouldn’t survive long with our immune system’s placing our tissues under constant attack. Thankfully, the “search and destroy” cells are not the only cells of the immune system. We also have teams of “memory cells” that learn the molecular structure of every bacteria and virus they ever encounter. When these cells detect the presence of a previously seen foe, they alert the immune system and initiate a swift attack.

A vaccine provides the immune system with several pieces of a dangerous microbe so that the memory cells can learn to recognize that deadly organism and destroy it before it has a chance to spread throughout the body.

But the Flu Changes Every Year...

A major issue with influenza is that it rapidly changes its outward appearance, making it difficult to create a flu vaccine that allows the memory cells to recognize it. That’s why the makers of the flu vaccine include not only pieces of the predicted surface molecules, but also pieces of the core flu structure that doesn’t change year to year. It’s important to note that you cannot get the flu from the flu shot, because it does not contain an intact virus—it contains only inert pieces of the virus so your memory cells gain familiarity.

The flu virus moves fast, but when the immune system is primed to recognize it, the defense process starts sooner, resulting in less severe illness. And if the flu is not given the time to invade the cells, the immune system will not need to resort to such an extreme, and potentially fatal, response. So while the flu shot may not be perfect, getting the flu shot can still be lifesaving.

author name

Joan B. Thode, MD

Joan B. Thode, MD, FAAP, is a pediatrician with LG Health Physicians Roseville Pediatrics.

Education: Undergraduate–Franklin & Marshall College; Medical School–George Washington University School of Medicine and Health Sciences, Residency–NYU Langone Medical Center.

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About LG Health Hub

The LG Health Hub features breaking medical news and straightforward advice to help individuals of all ages make healthy choices and reach their wellness goals. The blog puts articles by trusted Lancaster General Health clinical experts, good 'n healthy recipes, videos, patient stories, and health risk assessments at your fingertips.


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