What are the side effects of the updated COVID vaccine?

The most common side effects are the same as earlier versions of the vaccine--rash and soreness at the injection site, headache, fever, and fatigue. Symptoms are typically mild and last 1-3 days.

The most common side effects of the updated COVID-19 vaccine are rash and soreness at the injection site, headache, fever, and fatigue. Symptoms are typically mild and last 1-3 days. The side effects of the updated COVID-19 vaccine are similar to that of the earlier versions.

Adults and children have similar side effects from the updated COVID-19 vaccine. They tend to be mild and start within 24 hours of the injection, and usually go away in 1-3 days. 

The most common side effects are: 

• “COVID arm” – red/itchy rash at the injection site with pain and swelling

• Flu-like symptoms (such as chills, fever, muscle pain)

• Headache

• Fatigue or a general sense of not feeling too good 

A less common reaction is swollen lymph nodes in the underarm area on the same side as the injection, which may last up to 10 days.

The side effects of the updated COVID-19 vaccine are similar to that of the earlier versions. They are also mostly the same across the various vaccines – Pfizer, Moderna, Novavax, with slightly fewer side effects from Novavax.

Other factors play a role in the side effects. Being tired or stressed and having had any other recent infection can increase side effects. People below 55 years of age tend to experience more fever, fatigue, and achiness, since their immune system is more responsive compared to people over 55 years. 

On the other hand, some people will not have any side effects. This does not mean the vaccine is not working or that you will not be protected against the current strains of COVID-19! 

It is also possible to have side effects with the updated COVID vaccine even if you did not have one to the previous versions and vice-versa. That is because our reaction to vaccines depends on our immune system, our current health, and the formula of each vaccine.

The good news is that side effects can usually be managed at home: 

• If possible, plan to get your vaccine when you are able to rest for a day or two afterward if needed. 

• Make sure you stay hydrated and drink plenty of fluids for 1-2 days after the injection. 

• If you have soreness or swelling at the injection site, moving the arm right after getting the injection, keeping it elevated, and applying an ice pack can help relieve those symptoms. 

• You can treat soreness, headache or fever with over-the-counter medications such as acetaminophen or ibuprofen *after* you get the injection.

If the symptoms don’t get better after a few days, or the pain gets worse, talk to a clinician. It is recommended to act sooner for children – if the symptoms are severe or last more than 3 days, contact a clinician.

Although we are seeing fewer hospitalizations and deaths from COVID-19 compared to earlier in the pandemic, these are both on the rise in many parts of the U.S. as the weather has turned colder and people are gathering indoors.

Along with other precautions such as staying home if sick and  masking strategically, it's important to get the updated vaccine to prevent the spread of serious infections. The vaccine is still our best defense against COVID-19.