yego.me
💡 Stop wasting time. Read Youtube instead of watch. Download Chrome Extension

Flu Virus 101 | National Geographic


2m read
·Nov 11, 2024

  • [Narrator] The flu is a highly contagious respiratory illness. It turns up year after year with devastating consequences, all caused by a most elusive virus.

The influenza, or flu virus, is a recurring nightmare. It causes more than 36,000 deaths in the U.S. each year and was responsible for some of history's deadliest pandemics. Like other viruses, the flu virus is a parasite. The viral agent itself, called a virion, is made of ribonucleic acid or RNA surrounded by proteins.

The flu virus uses two proteins to attack its host: hemagglutinin and neuraminidase, or the HA and NA proteins. The HA protein attaches a virus to a cell and lets it in. Once the virus is inside, it multiplies. Then the NA protein cuts this viral swarm loose, sending it off to infect more cells.

This triggers the immune system to bombard the swarm and to destroy infected tissue throughout the respiratory system. Unfortunately, this response can also inadvertently lead to death through organ failure or secondary infections like bacterial pneumonia.

The flu virus has been nearly impossible to eradicate, largely due to its uncanny ability to mutate. Since just 2004, more than 5,000 different strains of the influenza virus have been sequenced. Those that affect humans are categorized as Types A, B, or C, with Type A strains being the most capable of unleashing a pandemic.

Influenza A viruses mutate more rapidly, allowing them to adapt to new hosts and even cross species. Avian flu and swine flu, for instance, are two strains of Type A viruses that, through mutations, can be transmitted from birds and pigs to humans.

One of the deadliest flu pandemics was caused by one such virus. Between 1918 and 1919, the Spanish flu infected a third of the global population and killed up to 50 million people worldwide. Called H1N1, this particular strain of virus likely came from birds.

The threat of another influenza pandemic remains. In the meantime, scientists are constantly monitoring the flu virus and developing seasonal vaccines to create our best line of defense.

More Articles

View All
2015 AP Biology free response 2 a b
All right, cellular respiration includes the metabolic pathways of glycolysis, the Krebs cycle, and the electron transport chain, as represented in the figures. So we have the figures here of glycolysis, the Krebs cycle, and the electron transport chain. …
The Bullet Block Experiment
Alright, here is the setup: I have a rifle mounted vertically and we’re going to shoot a bullet into this block, right into the middle of it. So obviously the block is going to go flying into the air. But we’re going to do this again and instead of firin…
Prompting basics | Introducing Khanmigo | Khanmigo for students | Khan Academy
In this video, we’re going to see that you can have very different experiences with the same AI, and a lot of that is depending on how we prompt the AI. So before we even start doing some prompting ourselves or even understanding what that means, let’s ju…
The Lasting Scars of War | No Man Left Behind
[Music] When I joined the regiment, you read about SAS history, and um, I can remember uh reading a story about a guy called uh Jordi Silico. He held the record for walking through the desert in North Africa, and it was 100 miles. It was the longest escap…
15 Little Habits To Have a Better Day
You know, Alexir, the simplest habits are the most effective. They’re preached over and over again for a reason. It’s because those habits help you live a peaceful, productive, and satisfying life. Eat your greens and your protein, floss daily, put on sun…
Origins of the Cold War
Hi Dr. Kuts. Hello David. How you doing? I’m doing well. I am excited to learn about this thing we call the Cold War. What is a Cold War, and what makes it different than a hot war? So a Cold War, and in this case, is it’s really, um, it might be a te…