What are the long term effects of the COVID vaccine in kids?

Safety data from clinical trials

The Pfizer COVID-19 vaccine is highly effective at preventing symptomatic infection, including against the Delta variant, among children and adolescents. The safety data to support its emergency use in children ages 5-11 years included more than 4,600 participants (3,100 vaccine, 1,538 placebo) and found no serious adverse events related to the vaccine after more than two months of follow-up.

Types of Vaccine side effects

When we talk about side effects from a vaccine or other medicine, we generally divide them 

into: 

• Mild, short-term side effects that can be annoying, but are not dangerous.
• Serious side effects that occur soon after vaccination.
• Delayed-onset or long-term side effects.

Any vaccine can lead to short-term side effects that are annoying but not dangerous. These  include things like a sore arm, headache, fatigue, or chills. COVID vaccines–like many others–cause these side effects in some people. These side effects go away in a few days.

Serious side effects are very rare, but can occur following any vaccination, including COVID-19 vaccination. These side effects include severe allergic reactions or myocarditis. So far, all kids and teens who had a severe, documented side effect have recovered. 

Both mild and serious side effects generally all occur within six to eight weeks of getting the shot; this is true for both the COVID vaccines and other vaccines.

Delayed-onset or long-term side effects have been identified for some vaccines. These vaccines use a live viral vector to produce immunity. One of the benefits of the mRNA vaccines used for COVID vaccines is that there is no live viral vector. Because of this, there is no way for these vaccines to cause long-term or delayed-onset side effects like changes to fertility.

mRNA vaccines are not new

What we know about mRNA adds to the confidence in their safety. While mRNA technology seems new, these vaccines are the result of more than three decades of research. The mRNA molecule in the COVID-19 vaccine begins to disintegrate after about six hours and is completely gone by 48 hours post vaccination. During that time your body begins to create antibodies to prepare your immune system to fight the actual virus if it is encountered. Since nothing remains of the vaccine after a few days, the possibility of adverse long term effects are low.

Experts agree!

Experts agree, the risks of COVID-19 infection are much higher than any risk of long-term complications from the vaccination. Additionally, these vaccines continued to be monitored for safety with the most comprehensive and intense safety monitoring program in U.S history.

 Last update: December 3, 2021 10:20 am ET

Science review: GSN, ERS, JAB