What you need to know about vaccines and immunization

doctor talking to patient

There’s been a lot of coffee-shop talk about vaccines since the pandemic. Learning the facts for yourself is key so you can make the best decision for your health. The Centers for Disease Control and Prevention (CDC) says that vaccines are “the safest way to protect against certain diseases and prevent serious illness.”¹ Plus, the World Health Organization estimates that between 2 and 3 million lives are saved each year by vaccines.²

What is a vaccine?

A vaccine is a type of medicine that uses the body’s natural defenses—your own immune system—to build resistance against infection. Vaccines imitate the properties of specific viruses and create copycat infections that help prepare the body to fight off a viral attack, while building an immunity against it. In short, vaccines trick the immune system into making the effects of the incoming germs less harmful. Vaccines can be administered by injection, liquids, pills or nasal spray.

Are vaccines safe?

The CDC plays an important role in making sure that our nation’s vaccines are safe. Its Immunization Safety Office regularly monitors vaccine safety to keep the public informed on the benefits and risks of new vaccines.³ The CDC also advises that no vaccine is perfect and it’s still “possible to get a disease even when vaccinated, but the person is less likely to become seriously ill.”¹

That said, some vaccines do have minor side effects. For example, the live influenza shot can sometimes give patients a runny nose, wheezing and headaches, among other symptoms.⁴ The CDC has compiled a helpful list of side effects for the most popular vaccines, from hepatitis A to zoster (shingles) shots.

Side effects can be tough, but they can also be an important sign that a vaccine is working. Take the COVID-19 vaccine, for example. As a recent scientific article noted, “the prospect of fatigue and headache after vaccination for COVID-19 should be viewed positively: as a necessary prelude to an effective immune response.”⁵ These minor physical discomforts can be actual proof that your immune system is having its intended response to the vaccine.

What’s the difference between vaccinations and immunizations?

When we encounter a harmful virus or bacteria, our bodies generate a primary immune response to the viral attack. A vaccination is the act of introducing a vaccine into the body, thus triggering a primary immune response of its own to prevent an illness from spreading. An immunization is the process of protecting a person from getting sick by taking a vaccine.

Why should you get vaccinated?

The National Foundation of Infection Diseases (NFID) has compiled 10 reasons why you should keep current with your vaccines. The NFID notes that doing so can be lifesaving, as “every year in the U.S., prior to the COVID-19 pandemic, approximately 50,000 adults died from vaccine-preventable diseases.”⁶ To find out which vaccines you should be up to date with, the Department of Health and Human Services (HHS) has created a handy resource page for your convenience. The CDC offers a similar resource as well. The CDC also has a state and local vaccination resource page that provides additional vaccine information on a state-by-state basis and more.

If you’re planning on leaving the country, you may need to protect yourself from diseases that are rare in the U.S. (such as yellow fever, malaria and typhoid), but still active in other countries. The CDC has a helpful Travelers’ Health page with lots of useful immunization information for anyone planning a trip abroad.

When should you get these common vaccines?

The CDC suggests that adults should get a flu shot every year and a tetanus booster every 10 years. The agency also recommends that you get your flu shot early, before the flu season begins (which typically runs from October to February), because the vaccine takes about 2 weeks to become fully effective. Adults age 65 and older should get the pneumococcal vaccine, and anyone born after 1980 should be vaccinated for chickenpox. Adults age 50 and older should get the shingles vaccine, while the measles, mumps and rubella (MMR) vaccine should be given to anyone born in 1957 or later. As far as current information regarding the COVID-19 vaccine, consult this CDC page.

How and where to get vaccinated

Depending on the vaccine, CenterWell Pharmacy® may have what you need. If you live near one of the 45 CenterWell Pharmacy retail locations nationwide, you may be able to get your vaccines at little or no charge. Find a location near you. You can also contact your primary healthcare provider for more information on where to get vaccinated in your community.

To find out which vaccinations your healthcare plan covers, sign in to MyHumana, then go to the Coverage and Benefits page. You can also speak with Humana member services directly by calling the phone number on the back of your member ID card, or by calling 800-379-0092 (TTY: 711), Monday – Friday, 8 a.m. – 11 p.m., and Saturday, 8 a.m. – 6:30 p.m., Eastern time, for more assistance.


  1. Understanding How Vaccines Work,” Centers for Disease Control and Prevention, last accessed Feb. 2, 2023.
  2. Vaccines and immunization: Vaccine safety,” World Health Organization, last assessed Feb. 2, 2023.
  3. About the Immunization Safety Office (ISO),” Centers for Disease Control and Prevention, last assessed Feb. 2, 2023.
  4. Possible Side Effects from Vaccines,” Center for Disease Control and Prevention, last assessed Feb. 2, 2023.
  5. Jonathan Sprent and Cecile King, "COVID-19 vaccine side effects: The positives about feeling bad," Science Immunology 60, no. 6 (June 2021), accessed Feb. 2, 2023, doi:10.1126/sciimmunol.abj9256.
  6. 10 Reasons to Get Vaccinated,” National Foundation of Infectious Diseases, last assessed Feb. 2, 2023.

Disclaimer: This material is provided for informational use only and should not be construed as medical advice or used in place of consulting a licensed medical professional. You should consult with your healthcare provider to determine what is right for you.

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