Why can you get a common cold or other disease more than once?

The common cold and other diseases are caused by viruses or bacteria. When a person gets sick, their body produces antibodies to fight off the infection. These antibodies are designed to recognize and attack specific viruses or bacteria. However, some viruses and bacteria can change their appearance over time, which allows them to evade the immune system. This is why people can get sick from the same virus or bacteria more than once.

Additionally, some viruses and bacteria can cause latent infections, which means they can hide in the body for a long period of time without causing any symptoms. When a person's immune system is weakened, these latent infections can reactivate and cause illness.

Some examples of diseases that people can get more than once include:

- The common cold

- Influenza

- Measles

- Mumps

- Rubella

- Chickenpox

- Shingles

- Herpes simplex

- Genital warts

- Human papillomavirus (HPV)

- Hepatitis A, B, and C

It is important to practice good hygiene and get vaccinated to help prevent the spread of these diseases.