How is your body able to fight and clear some viral infections over time?

Your white blood cells aim to destroy the unwelcome guests.

They get their start in your bone marrow. They have a short life -- ranging from a few days to a few weeks -- so your body constantly makes more. There are different types, and they all have the same goal: to fight infection.

They wait, poised for duty, in many different places in your body, including your:

Thymus
Spleen
Tonsils
Blood vessels
Lymph nodes
Small intestine
Adenoids
Lymph Lends a Big Hand

Your lymphatic system is like an inner highway that carries white blood cells through your body.

When you’re sick, you might notice your lymph nodes -- small glands in your neck, groin, armpits, and behind your knees -- are swollen. This is normal. It means your immune system has kicked into high gear to get rid of infection.

Lymph nodes are also filters for your immune system. They catch germs and dead or damaged cells and destroy them.

Hope this helps :)

Your body is able to fight and clear viral infections over time because your body has become immune to it or can tolerate it

Although i don't know what is the simulated system, starfish are predators that eat mostly  microalgae,  snails, sponges, bivalves, mussels and other small marine animals. removing starfish from any system would definitely increase this animals that they prey.