Do vaccines have side effects? What reactions are considered serious?
As is the case with any medication, vaccines can have side effects. However, the majority of vaccine side effects are very mild, such as soreness or redness where the vaccine was given, or a low-grade fever. These side effects usually go away within a few days. Serious side effects following vaccination, such as a severe allergic reaction, are very rare.
In general, parents should pay extra attention to their children’s overall health for a few days after vaccination (and your own health if you have been vaccinated). If you notice something that concerns you, call your healthcare provider.
When deciding whether or not to vaccinate your family members, remember that the diseases from which your family is being protected can be very dangerous or even deadly. Even though many of these diseases are rare in the United States, they still occur around the world and unvaccinated people who travel to other countries can bring these diseases to the U.S., placing unvaccinated people at risk. One example of this was the large, multi-state measles outbreak that started in Disneyland in California. The outbreak began from a person who became infected with measles when traveling overseas, and then, while still infectious, visited Disneyland. The majority of people – 188 people in 24 states and DC – who ended up sick with measles were unvaccinated.
It is very important to weigh the science-based risks versus benefits of vaccines. For instance, while a sore arm, or a fever and fussiness in your child after being vaccinated is never easy, it means that the vaccine is working by creating an immune response (protection) that may last a lifetime.
The CDC’s Vaccine Information Statements (VIS), which are created for every vaccine recommended in the United States, explain both the benefits and risks of the vaccines.
What do I do if my child has a serious reaction to a vaccine?
If you are concerned that your child has had a serious reaction to a vaccine, call your healthcare provider or 911 immediately. Most people who get vaccinated have no serious after effects. However, vaccines, like any medicines, can cause side effects. Most of these side effects are very mild like a low fever. If your child experiences a reaction at the vaccine injection site, use a cool, wet cloth to reduce redness, soreness, and swelling. Speak to your healthcare provider about fever/pain reducing medicines.
In very rare cases, a vaccine can cause a serious problem, such as a severe allergic reaction. Its important to note that some health problems that follow vaccinations are not necessarily caused by the vaccines, but if you notice something that concerns you, call your child’s healthcare provider.
The CDC’s Vaccine Information Statements (VIS), which are created for every vaccine recommended in the United States, explain both the benefits and risks of the vaccines and how to report serious side effects.
If your child received a recommended vaccine and you believe he or she was injured as a result, you can file a report in the Vaccine Adverse Event Reporting System and you may file a legal claim with the National Vaccine Injury Compensation Program (VICP). The VICP may provide financial compensation to individuals who file a petition and are found to have been injured by a covered vaccine.
What if an adult or pregnant woman has a serious reaction to a vaccine?
If you are concerned about a serious reaction to a vaccine, call your healthcare provider or 911 immediately.
The CDC’s Vaccine Information Statements (VIS),which are created for every vaccine recommended in the United States, explain both the benefits and risks of the vaccines and how to report serious side effects.
The CDC’s Advisory Committee for Immunization Practices (ACIP) recommends vaccines for people of all ages, and they are tested before and after being licensed by the FDA for use in the United States. Serious side effects from vaccines are very rare, but if you are concerned about any health problems after vaccination, you should contact your healthcare provider right away. Any person who received a recommended vaccine and believes he or she was injured as a result, can file a report in the Vaccine Adverse Event Reporting System.
Any adult who received a vaccine that is also routinely recommended for children (i.e. flu, pertussis) and believes he or she was injured as a result, can file a petition with the National Vaccine Injury Compensation Program (VICP). There are no age restrictions.
The CDC’s ACIP, the American College of Obstetricians and Gynecologists (ACOG) and the American College of Nurse-Midwives recommend flu and pertussis (Tdap) vaccines for all pregnant women. These vaccines have been studied and have been shown to be safe for pregnant women and their babies. However, in case of a rare serious reaction to the vaccine, a pregnant woman can file a claim for herself or her baby within the National Vaccine Injury Compensation Program (VICP).
Who monitors the safety of vaccines in the United States?
Before being approved for use in the people of all ages, vaccines go through in-depth testing. Clinical trials are performed before the vaccine is made available to confirm the vaccine’s safety and efficacy (the ability to produce the intended result)– both as an individual vaccine and when it is given with other vaccines according to the recommended vaccine schedule.
Even after a vaccine receives FDA-approval and is recommended for use by the CDC, post-licensure studies are done on an ongoing basis to continually monitor the vaccine’s safety, and to detect and respond to any rare adverse events. The CDC and FDA monitor and evaluate the safety of vaccines through the Vaccine Adverse Event Reporting System (VAERS), the Vaccine Safety Datalink (VSD), the Clinical Immunization Safety Assessment Project (CISA) and the Post-Licensure Rapid Immunization Safety Monitoring System (PRISM).
- VAERS is a national vaccine safety surveillance program that invites healthcare providers, along with anyone who believes that they or someone they know experienced a vaccine side effect, to file a report. VAERS data alone usually cannot be used to answer the question, “Does a certain vaccine cause a certain side effect?” This is because adverse events reported to VAERS may or may not be caused by vaccines. There are reports in VAERS of common conditions that may occur by chance alone that are found shortly after vaccination. Instead, VAERS helps scientists identify any unusual patterns of reported adverse events that MIGHT indicate a problem with a vaccine and whether additional work and evaluation is needed to determine possible safety concerns. This helps to ensure the benefits of vaccines continue to be far greater than the risks.
- The Vaccine Safety Datalink (VSD) is a collaboration between CDC and nine healthcare organizations that began in 1990 and includes millions of vaccine records of patients. When new vaccines are recommended in the U.S. or if there are changes in how a vaccine is recommended, the VSD helps to monitor the safety of these vaccines. The VSD also conducts studies based on questions or concerns about vaccine safety raised from the medical literature and VAERS reports. Scientists use VSD to do studies that help determine if possible side effects identified using VAERS are actually related to vaccination. When new vaccines are recommended for use in the U.S. or when there are changes in how a vaccine is recommended, the VSD monitors the safety of these vaccines.
- CISA is a national network of vaccine safety experts that was created in 2001 to address any unmet vaccine safety clinical research needs of the U.S. CISA addresses vaccine safety issues, conducts high quality clinical research, and assesses complex clinical adverse events following immunization (AEFI). CISA facilitates CDC’s collaboration with vaccine safety experts at leading academic medical centers and strengthens national capacity for vaccine safety monitoring. CISA provides consultation to U.S. clinicians who have vaccine safety questions about a specific patient, and provides consultation to U.S. healthcare providers and public health partners on vaccine safety issues, and reviews AEFI involving the U.S.-licensed vaccines.
- PRISM is a partnership between the FDA’s Center for Biologics Evaluation and Research and leading health insurance companies. It actively monitors and analyzes data from a representative subset of the general population. PRISM links data from health plans with data from state and city immunization information systems (IIS). PRISM has access to information for over 190 million people allowing it to identify and analyze rare health outcomes that would otherwise be difficult to assess.