What is diphtheria?
It is an illness caused by germs (bacteria) that infect the nose, throat or skin. It causes serious problems with breathing. It can also cause heart failure and nerve damage for the rest of your life. Of every 10 people who get diphtheria, 1 will die from it. Babies who get it are even more likely to die. 

What is tetanus?
It is also called lockjaw. 
It is caused by germs (bacteria) that live in dirt. When the tetanus germ gets into an open cut, poison from the germ can spread to nerves and then to muscles. Muscles may lock in one place or go into spasms (get very tight). This is very painful. The first muscles affected are the ones in the jaw. Your child may not be able to swallow or open his or her mouth. This is why tetanus is called lockjaw. If tetanus gets to the muscles that help your child breathe, your child can die very quickly. Children who survive tetanus may have long-lasting problems with speech, memory and thinking. Even if they have it once, they can still get it again. The tetanus shot protects both adults and children. Ask your doctor how you can get a tetanus shot so you can protect yourself, too. 

What is pertussis?
It is also called whooping cough. It used to kill many young children. 
It is caused by germs (bacteria) that get into the throat and lungs. 
Children may cough so long and so hard that they can’t breathe. 
Babies with whooping cough may have fits (seizures) and go into a coma. 1 out of 400 babies under a year old who gets whooping cough will end up with brain damage. 
Older children who get whooping cough will have 2 to 3 weeks of severe coughing spells. In total, the disease can last from 6 to 12 weeks. 

What is polio?
It is a disease caused by 1 of 3 types of the polio virus. Polio can cause fever, headache, vomiting (throwing up), strong muscle pain and muscles that won’t move (are paralysed). It can also make children very tired and cause stiffness in the neck and back. Some people with polio don’t feel sick at all. Others are paralysed (can’t move their arms or legs) for the rest of their lives. Some people die. 

What is Hib?
Hib stands for Haemophilus influenzae type b. In spite of its name, it has nothing to do with the flu. Hib is the name of germs (bacteria) that can infect the fluid around the brain and spinal cord. Hib can cause a very serious disease called meningitis. Without treatment, all children who get this disease will die or suffer damage that lasts for the rest of their lives. Hib can also lead to other serious diseases that can kill.Even with treatment, about 1 in 20 children with Hib meningitis will die. 
About 1 in 3 children who live will have brain damage. 

What is chickenpox?
It is an illness caused by the varicella-zoster virus. People with chickenpox get an itchy rash or spots on their skin. The spots are like small water blisters. Some people have only a few blisters. Others can have as many as 500. These blisters dry up and form scabs in 4 or 5 days.

What is hepatitis B?
It is a disease caused by a virus. A virus is a kind of germ that can make people sick. The hepatitis B virus attacks the liver. Sometimes, people with hepatitis B do not feel sick at all. But they can still pass the disease on to other people. They are called carriers. In other cases, hepatitis B makes people very sick. It can cause serious damage to the liver and long-lasting (or chronic) liver disease. Hepatitis B is one of the main reasons people get liver cancer. There is no cure for hepatitis B. 

HPV vaccine - (Human papillomavirus)
There are many different types of HPV. Many of them can affect the genital area of men and women including the skin of the penis, vulva (area outside the vagina) or anus, and the linings of the vagina, cervix, or rectum. 

Most people with HPV infection do not know they have it because it usually causes no symptoms. But, HPV is the major cause of cervical cancer in women. The virus must be present for many years before it develops into cancer. It can also cause genital warts in both men and women. 

Influenza (flu) vaccination is safe for anyone 6 months of age and older who wants to protect themselves and those around them from flu and its complications. 

What is measles?
It is a disease caused by a virus. Sometimes it is called “red measles” (or rubeola) so it will not be confused with “German measles” (or rubella). 

Measles begins with a fever, runny nose, a cough and very red eyes. You may think your child has a cold. In a few days, a rash begins around the face and spreads to the chest, arms and legs. The eyes may hurt in bright light. Measles can cause an ear infection or pneumonia (a serious disease where fluid fills the lungs). Out of 1,000 children who get measles, 1 will also get a swelling of the brain called encephalitis. This can lead to fits (seizures), deafness, mental retardation or death. There is no treatment for measles. 

What is mumps?
It is a disease caused by a virus. Mumps is most common in children, although sometimes adults get it, too. Mumps causes fever, headache and swelling of the saliva glands (inside the mouth). This swelling is painful and makes the cheeks puff out. Sometimes, mumps can cause meningitis, a serious disease that infects the fluid around the brain and spinal cord. 
Mumps can cause deafness. In adults, mumps can affect a woman's eggs or a man's sperm. A man who gets mumps may become sterile (not be able to have children). For both men and women, mumps can be very painful. 

What is rubella?
It is also called German measles. Like red measles, rubella is caused by a virus. It is milder than red measles. Children get a low fever and a mild cold. A rash may follow. Glands in the neck may swell up. The sickness lasts about 3 days. 

Meningitis (brain infection)
Meningitis is a serious disease that infects the brain and spinal cord. 
Without treatment, all children who get this disease will die or suffer damage that lasts for the rest of their lives. Meningitis can cause seizures, deafness or brain damage. Symptoms of meningitis include high fever, stiff neck, headache, vomiting, fussiness (crying), and loss of appetite (for example your child may not want to eat anything). 

Bacteremia (bloodstream infection)
Bacteremia is an illness caused when germs (bacteria) get into the blood. 
Sometimes it goes away on its own. But if the germs multiply and travel to other parts of the body, it can cause permanent damage. 
Symptoms are similar to those of meningitis: high fever, stiff neck, headache, vomiting, fussiness, and loss of appetite. 

Pneumonia (lung infection)
Pneumonia causes the lungs to fill with fluid. People with pneumonia have trouble breathing. Children who get pneumonia from the pneumococcal germ will have a fever and cough that may bring up thick mucous. They will also become very ill quickly. 

Otitis media (middle ear infection)
When a person has a middle ear infection, the eardrum turns red, and the space behind it fills with fluid or pus. Many different germs can cause ear infections, including the pneumococcal germ. Children under 2 years old sometimes get middle ear infections when they have a cold. Middle ear infections can cause ear pain, fever, lack of energy, fussiness, and a lack of appetite. 
 

Source/Reference: 
Your Child's Best Shot: A Parent's Guide to Vaccination, a 392-page book produced by the Canadian Paediatric Society (CPS). 
 

This information should not be used as a substitute for the medical care and advice of your physician. There may be variations in treatment that your physician may recommend based on individual facts and circumstances.