Question

A vaccine contains the following:

• A. Weakened bacteria
• B. Active bacteria
• C. Vector
• D. Medicines

Answer 1

The correct option is A

Weakened bacteria

The correct option is A:

Explanation of the correct option :

1. Vaccine is a preparation which is injected in our body to trigger body's immune system against diseases.
2. It contains killed or weakened bacteria of a disease.
3. After a vaccine is injected, our immune system reacts by producing antibodies against the bacteria.
4. These antibodies remain in the body and provide protection when actually this bacteria attacks us.
5. So vaccines are injected to prevent the occurrence of a disease in us.
6. Vaccines are disease specific like TAB vaccine is for tuberculosis, BCG vaccine is for typhoid etc.

Explanation of the incorrect option:

Option B:

1. Vaccines do not contain the active bacteria as it will cause the disease in the person.

Option C:

1. Vector is a carrier of disease causing organisms from an infected to an uninfected individual like mosquitoes are malarial vector as they carry the malarial protozoa from an infected to an uninfected individual.

Option D:

1. Medicines are used for the treatment of diseases.

Final answer: A vaccine contains weakened bacteria.