You know that when your body produces antibodies to fight antigens, the antibodies remain in your blood to protect you in case you are in contact with the disease again. Vaccines act similarly to protect you from diseases before you come into contact with the virus that causes a particular illness. The immunity that comes from introducing something into the body is passive immunity. In this activity, you will learn about the ways vaccines and antibiotics assist human disease defences.

Vaccines

A vaccine is made from a noncontagious form of an antigen. When you receive this antigen, you have been vaccinated. Vaccinations are most often by an inoculation, also called a needle or shot. Some vaccines have now been developed that can be taken orally (by mouth). Your body uses its immune responses to form antibodies to protect you from the disease. That way, when you come into contact with the antigen later in life, you already have the antibodies in your blood to protect you from the illness.

You may recall from earlier lessons that vaccines are available for some of the most common communicable diseases that could cause serious health problems for you.

Click below to see a table that lists preventable diseases and the effects of each disease.

Preventable Diseases and Their Effects

(If you are considering travelling outside Canada, you should check with your local health unit to find out if you should have any other vaccinations for diseases that you may be in danger of encountering in another country. In fact, some countries will not allow you to enter unless you have proof of certain immunizations.)

The only way you can acquire immunity from a disease is by having a form of the disease and developing antibodies to fight the disease or by having a vaccination against the disease and developing antibodies that way. The best way to protect yourself is to keep your immunizations up to date.

You should know that although people are encouraged to get vaccinations, it is not a law that everyone must be vaccinated. Parents decide whether their children will be vaccinated. When you are an adult, you can determine if and when you will get vaccinations for various diseases that you are not protected against.

Antibiotics

When people become ill, many try over-the-counter medications to treat or relieve symptoms such as headaches and fevers. If symptoms of infection continue, a doctor will sometimes prescribe a drug called an antibiotic. Antibiotics fight bacterial infections by either preventing bacteria from reproducing or by killing the bacteria. Each antibiotic is effective against specific types of bacteria. Antibiotics, however, do not help with viral infections.

When you catch a cold or get strep throat, you need to know whether the infection is bacterial or viral. Viruses cause colds, most sore throats, coughs, the flu, and sinus infections. Antibiotics do not work against viruses, so the best thing you can do for these conditions is drink plenty of fluids, get rest, and maybe take over-the-counter drugs to relieve symptoms. Since bacteria cause strep throat and pneumonia, an antibiotic may be effective in the treatment of these conditions. 

 Problems with Antibiotics

Some people want to take antibiotics to fight every cold and sore throat they have. This is not a good idea. Here's why:

• Antibiotics kill both harmful and helpful bacteria. Your body contains many helpful bacteria that help with things such as digestion. Antibiotics kill these and can cause symptoms such as an upset stomach or diarrhea.

• Antibiotics can cause side effects. Some people may develop allergies to antibiotics.

• Overusing antibiotics may develop resistant bacteria. Here's how this happens:

         1. When you take an antibiotic, it usually kills bacteria over a period of 7 to 10 days. Some of the bacteria may become immune to the antibiotic. These bacteria survive and then reproduce.

      2. This results in the forming of a new antibiotic-resistant strain of infection. (If you don't take all of the antibiotic the doctor has prescribed, this can increase the chance of bacteria becoming resistant.) The resistant bacteria are often called superbugs.

     3.  When the superbugs reproduce, the new strain of the disease begins to infect many people. These new superbugs are resistant to one, or sometimes many, antibiotics. Even if you are healthy and have never taken an antibiotic, you could become infected with a superbug from other people.

The best way to avoid this is by using antibiotics only when necessary and following your doctor’s directions for their use.