What is introduced into the body during vaccination?

What is active immunity and passive immunity?

Interferon is inhibitory to

What is an antibody?

The lymphoid tissue associated with the mucosa is known as .........

Person '$A$' cannot step out of his house. He has to spend his entire life in sterile isolation; otherwise, he would quickly contract a fatal infection. This person has almost no effective immune system. This disease is also called '$baby$ $in$ $a$ $bubble$ $syndrome$'. Identify the disease this person '$A$' is suffering from.