How Flu Viruses Survive

The flu changes every year so that it can find new host for survival. Hosts are alive. They are plants, animals, and people that provide food sources for germs. The flu is a viral germ. It requires a host to grow and multiply. As environments change, flu viruses must also change to adapt to new surroundings for survival.

The Changing Host

Every year, a new influenza vaccine is created to combat the virus that causes the flu. Based on information gathered from previous flu viruses, scientists work to combat future flu viruses. Sometimes, their efforts prove to be very accurate. They create a vaccine that easily combats the new strain of flu.

People who get flu shots develop immunities in their systems that fight off viruses causing the flu. Immunities prevent disease from entering the system by resisting its efforts. Their cells are stronger than the viral ones trying to attach to them. People with weak immune systems are not so lucky.

People are exposed to millions of germs every day. Most of the time, we remain healthy. That's because our immune systems are strong. The purpose of the immune system is to prevent harmful substances from attacking the body. As we are exposed to germs, our immune system makes adjustments to combat them.

The Immune System

The immune system is basically a huge network of cells. Together, they interact sending each other information. This information helps them create an army of defenses against intruders. The purpose of the immune system is to destroy these intruders, and carry them out of the body through waste products.

The parts of the body associated with the immune system are white blood cells, stem cells, antibodies, thymus, spleen, lymph nodes and tissue and lymphokines. All of these parts work together to fight off infection when we are exposed to it. When people build up antibodies against certain germs, they are able to avoid getting infected from them in the future.

Flu Viruses Mutate & Change

Flu viruses, like octopuses, have eight arms, or strands of genetic material. While most viruses only contain one strand of genes to divide and conquer surrounding areas, flu viruses are able to reach out in several different directions simultaneously. As they do this, their genetic material can get mixed up a bit. Sometimes, it changes during the process of reproduction, when the eight strands separate and multiply.

The strands in flu viruses are covered in two different proteins that have little spikes sticking out all over them. The first type of protein matches up with the respiratory system of a host. This is called an H spike. The second protein helps the virus enter cells on a prospective host. This is called an N spike. Together, these two proteins assist the flu virus in entering a host for breeding.

If a person's immune system recognizes flu proteins, it will defend against them with built up antibodies. The flu, however, is able to mix things up. Different viruses can combine, allowing for a greater chance at survival. When this happens, the immune system might not recognize the new strain of flu. Without recognition, antibodies are not developed to defend against the enemy.

The flu is a very common illness. When it becomes so popular, that everyone has built up immunities to it, the flu virus has the ability to jump to a different host. As it does so, it adapts to the new host, mutating in the process. Once the flu virus has changed through the breeding of several generations, it is able to jump back to the original host. If the immune system doesn't recognize the changes in the virus, it is able to attack and make people sick again.