Immunizations

Immunizations or vaccinations protect you from specific diseases, including:

• Measles
• Mumps
• Rubella
• Diphtheria
• Tetanus
• Chickenpox
• Rotavirus
• Pneumococcal infection
• Whooping cough (pertussis)
• Haemophilus influenza type B (Hib)
• Polio
• Hepatitis B
• Flu
• COVID-19
• HPV (human papillomavirus)

These diseases can cause severe, often lifelong health problems. Many can be fatal, but immunizations protect you and your children from these potentially devastating outcomes.

Immunizations work by causing an immune system response. When viruses, bacteria, or other microorganisms enter your body, your immune system locates them, identifies them, and releases antibodies from your white blood cells. Antibodies destroy the harmful microorganisms, and you avoid getting sick.

To create the right antibodies, your immune system needs to identify the infection. If it’s come across the specific virus or bacteria before, it reproduces antibodies from a blueprint it retains. In these cases, you might experience no symptoms or just mild ones because your body destroys the infection early.

When your immune system hasn’t encountered a microorganism before, it has to create the antibody blueprint. In the meantime, the infection develops, and you get sick but recover when the antibodies go into production. Immunizations use this process to trigger your immune system into making antibodies without you having to get sick first.

There are different kinds of vaccines. Some use dead bacteria or viruses; others use live versions that undergo modifications so they can’t infect you.

Certain vaccines use harmless versions of the toxins the microorganism produces. Newer vaccines contain pieces of inactive genetic material.

These substances all give your immune system the information to create antibodies.

Children receive most vaccines within their first few years. Some immunizations last a lifetime, while others require periodic boosters to maintain heightened immunity.

Flu requires an annual booster because the vaccine doesn’t protect against all the different flu strains. Each year, you get a vaccine that stops you from catching the most widespread strain at the time.

You might need to have other immunizations if you’re traveling to parts of the world where diseases like yellow fever (that aren’t a problem in the United States) are more common.