COVID-19 Vaccine Information

The Baltimore City Health Department offers free COVID-19 vaccinations to residents 6 months and older

2023-24 COVID Vaccine Information

On September 12th, 2023, the CDC authorized an updated version of the Moderna and Pfizer-BioNTech vaccines for everyone ages 6 months and older. These vaccines have been updated for the 2023-2024 respiratory virus season, and they target the most prevalent COVID virus variant, XBB.1.5.

Stay up to date on vaccinations for the greatest protection against COVID-19!


See all upcoming walk-up vaccination clinics
Register for a vaccination appointment

Do you need a vaccination at home?
You can register for an appointment online or call 443-216-9511 to schedule an individual who needs to receive the vaccine at home.

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Side Effects
How Do The Vaccines Work?
Additional Information


  • In December 2020, pharmaceutical companies Pfizer-BioNTech and Moderna were granted Emergency Use Authorizations (EUAs) by the Federal Drug Administration (FDA) for COVID-19 vaccines.
  • The approval of an Emergency Use Authorization by the FDA means the vaccine has been tested and is considered safe and effective for the general public to take.
  • As the virus has changed since 2020, new vaccine formulations have been created and approved to target certain variants. These updates mean that vaccination remains the most effective way to prevent severe disease, hospitalization, and death from COVID-19.

How do they work?

All COVID-19 vaccines help our body develop immunity against COVID-19 disease. Immunity means that your body will quickly recognize the virus that causes COVID-19 and your immune system will fight against it. This will protect you from getting as sick with COVID as you might otherwise.

  • Both the Pfizer-BioNTech and Moderna vaccines are known as mRNA vaccines. 
    • mRNA vaccines teach our bodies' cells to produce harmless copies of the COVID-19 spike protein. Our immune system knows that these spike proteins don't belong, and an immune response is triggered to fight against them. 
      • mRNA vaccines do not change your DNA 
      • mRNA vaccines do not contain weakened or inactive COVID-19 virus
      • mRNA vaccines do not cause disease
  • The Novavax vaccine is a protein subunit vaccine 
    • Protein subunit vaccines contain harmless copies of the COVID-19 spike protein - a small part of the virus. Our immune system knows that these spike proteins don't belong, and an immune response is triggered to fight against them.
      • Protein subunit vaccines do not contain the entire COVID-19 virus
      • Protein subunit vaccines do not cause disease

For more information about how the COVID-19 vaccines work, visit the CDC's "Understanding How COVID-19 Vaccines Work" page.

Is the COVID-19 Vaccine Safe?

  • Yes! The COVID-19 vaccines have been studied again and again since 2020 and the data shows that they are safe and that they work. People that get the vaccine are asked to report any side effects or adverse reactions, which are closely monitored. Due to the large number of people receiving the COVID vaccine since late 2020, these are some of the most closely studied medications in history!

How can we know it is safe and works if it was produced so fast?

  • Scientists have been working with mRNA vaccines for more than a decade and were able to quickly apply them to the COVID-19 virus in 2020. The extra money from the federal government allowed them to work faster, but without skipping any steps. Because the disease spread fast, they were able to show the vaccine worked much sooner than they would for other vaccines.

Side Effects of the COVID-19 Vaccines

The most commonly reported side effects are pain at the injection site, headache, fatigue, muscle aches, and nausea. Most of these side effects occur within 1-2 days following vaccination and are mild to moderate in severity, lasting only 1-2 days.

Some of those receiving the Moderna and Pfizer vaccines also reported fever, joint pain, and lymph node swelling, in addition to the side effects listed above. 

Additional Information