Q&As About Vaccination Options for Preventing Measles, Mumps, Rubella, and Varicella
Questions and Answers for Healthcare Providers
The Advisory Committee on Immunization Practices (ACIP) recommends a two-dose vaccine schedule for measles, mumps, rubella and varicella vaccines for children, with the first dose at age 12-15 months and the second at age 4-6 years.
Two vaccination options considered equivalent in terms of disease protection can be used to implement the ACIP recommendation among children 12 months-12 years of age: administration of trivalent measles, mumps, and rubella (MMR) vaccine and varicella vaccine (preferably at the same visit), or quadrivalent measles, mumps, rubella and varicella (MMRV)vaccine.
This web page was designed to answer questions that healthcare providers may have about the vaccination options and febrile seizures.
Questions and Answers:
Should I administer the MMR and varicella vaccines or the MMRV vaccine for a child’s first vaccination?
For the first dose of measles, mumps, rubella, and varicella vaccines at age 12-47 months, either MMR vaccine and varicella vaccine or MMRV vaccine may be used. Providers who are considering administering MMRV vaccine should discuss the benefits and risks of both vaccination options with the parents or caregivers. Unless the parent or caregiver expresses a preference for MMRV vaccine, CDC recommends that MMR vaccine and varicella vaccine should be administered for the first dose in this age group.
The discussion with parents or caregivers should focus on helping them understand the risks and benefits by using tools including the vaccine information statements. Compared with use of MMR vaccine and varicella vaccine at the same visit, use of MMRV vaccine results in one fewer injection but is associated with a higher risk for fever and febrile seizures 5-12 days after the first dose among children aged 12-23 months (approximately one extra febrile seizure for every 2,300-2,600 MMRV vaccine doses). Use of MMR vaccine and varicella vaccine avoids this increased risk for fever and febrile seizures following MMRV vaccine.
Studies of febrile seizures after vaccination with first dose of MMRV vaccine have not been done in older children, but experts agree that this increased risk of fever and febrile seizures during the 5 to 12 days after first dose vaccination likely also occurs in children aged 24-47 months.
When the first dose of measles, mumps, rubella, and varicella vaccine is administered at ages 48 months and older, use of MMRV vaccine generally is preferred over separate injections of MMR and varicella vaccines. [See the ACIP Recommendations.]Considerations should include provider assessment (including the number of injections, vaccine availability, likelihood of improved coverage, likelihood of patient return, storage and cost), patient preference, and the potential for adverse events.
What should I tell parents when discussing the options for their child’s first dose?
As their child’s healthcare provider, you remain parents’ most trusted source of information about vaccines. Providers who consider administering MMRV vaccine, instead of both MMR and varicella vaccines, for the first dose when a child is 12-47 months old should make sure parents or caregivers understand the benefits and risks of both vaccination options. CDC has developed the following materials to help you have this necessary conversation:
- Discussing Options with Parents: MMR & Varicella Vaccines or the MMRV Vaccine
This fact sheet was designed for healthcare providers and offers a summary of the risks and benefits associated with each vaccination option that you can use when discussing them with parents and caregivers, as well as general information on having successful conversations about vaccination.
- Know the Facts Before you Choose: Two Options for Protecting Your Child Against Measles, Mumps, Rubella, and Varicella
This fact sheet was designed for parents and caregivers and includes information about the risks and benefits of each vaccination option, as well as additional information to help them understand what febrile seizures are and why it is important to vaccinate against measles, mumps, rubella, and varicella.
Is there a Vaccine Information Sheet (VIS) available for MMRV vaccine?
Yes, there is a MMRV VIS, as well as a MMR VIS and a Varicella VIS. The law requires that a vaccine information statement (VIS) be given out whenever certain vaccinations are administered, including MMR, varicella or MMRV vaccines. The VIS is a one-page (two-sided) information sheet produced by CDC and informs vaccine recipients — or their parents or legal representatives — about the benefits and risks of a vaccine. Consult CDC’s Vaccines site for more information about VISs.
Is the MMR vaccine associated with an increased risk of febrile seizures?
MMR vaccination has previously been associated with febrile seizures occurring 8-14 days after vaccination; among children aged <7 years, approximately one additional febrile seizure occurs among every 3,000-4,000 children vaccinated with MMR vaccine, compared with children not vaccinated during the preceding 30 days.
Is the varicella vaccine associated with an increased risk of febrile seizures?
Studies have not shown an increased risk of febrile seizure after varicella vaccine.
What is the risk of febrile seizures after the first dose of MMRV vaccine compared with the first dose of MMR and varicella vaccines administered at the same visit?
Two postlicensure studies evaluated the risk of febrile seizures after MMRV vaccine in children aged 12-23 months; one was sponsored by Merck and the other was sponsored by CDC and conducted through the Vaccine Safety Datalink (VSD) — a collaboration between CDC and nine health care organizations that conducts active vaccine safety monitoring and research.
Review of findings from both postlicensure studies supports the conclusion that children who receive the MMRV vaccine when they are 12-23 months old are about twice as likely to have a febrile seizure during the 5-12 days following vaccination when compared with those who receive the MMR and varicella vaccines at the same visit. However, the overall risk of febrile seizures is very low for both options (about 8 out of every 10,000 children vaccinated with MMRV vaccine when they are 12-23 months old, and about 4 out of every 10,000 children vaccinated with the MMR and varicella vaccines at the same visit when they are 12-23 months old).
Studies of febrile seizures after vaccination with first dose of MMRV vaccine have not been done in older children, but experts agree that this increased risk of fever and febrile seizures during the 5-12 days after first dose vaccination likely also occurs in children aged 24-47 months because that is the biologic window of vulnerability for febrile seizures in children (approximately 97% of febrile seizures occur in children aged <4 years). First febrile seizures are uncommon after age 4 years.
What is the clinical importance of febrile seizures?
About 2-5% of young children will have at least one febrile seizure. Febrile seizures usually occur in children aged 6-60 months. The peak age for febrile seizures is 14-18 months, which overlaps with the ages when first doses of MMRV, MMR and varicella vaccines are recommended.
Febrile seizures generally have an excellent prognosis and most children have a full recovery. About a third of children who experience one febrile seizure will have another febrile seizure in the future.
One study suggests that children who have a febrile seizure shortly after vaccination with MMR vaccine are not more likely than children who have febrile seizures for other reasons to have future epilepsy or neurodevelopmental disorders. Experts believe it is likely that the findings for MMR vaccine would also be applicable to MMRV vaccine.
What effect do febrile seizures have on parents and caregivers?
Parents and caregivers can be very frightened and distressed when their child experiences a febrile seizure. Parents or caregivers of children who have a first febrile seizure are likely to seek medical attention for their child, which commonly includes a visit to an emergency department. Studies suggest that parents and caregivers generally consider febrile seizures to be a more severe adverse event than physicians do. Multiple studies show that when a child experiences a febrile seizure, it may have a negative effect on the family due to the stress felt by the parents and caregivers.
Is there an increased risk of fever or febrile seizures associated with the MMRV vaccine when given to a child who is 4-6 years old?
In clinical trials, the proportion of children aged 4-6 years who experienced fever following vaccination was similar among those who received the MMRV vaccine and those who received MMR and varicella vaccines at the same visit.
Furthermore, data from postlicensure studies do not suggest that children aged 4-6 years who receive MMRV vaccine have an increased risk for febrile seizures after vaccination compared with same-age children who receive MMR and varicella vaccines at the same visit.
Should I administer MMR and varicella vaccines or the MMRV vaccine for the second dose?
For the second dose at any age (15 months-12 years), use of MMRV vaccine generally is preferred over separate injections of MMR and varicella vaccines). [See the ACIP Recommendations.] Considerations should include provider assessment (including the number of injections, vaccine availability, likelihood of improved coverage, likelihood of patient return, storage and cost), patient preference, and the potential for adverse events.
Should a child with a personal or family history of seizures receive MMRV vaccine?
A personal or family history of seizures is a precaution for MMRV vaccination. Studies suggest that children who have a personal or family history of febrile seizures or family history of epilepsy are at increased risk for febrile seizures compared with children who do not have such histories. Children with a personal or family history of seizures (in siblings or parents) should generally be vaccinated with separate MMR and varicella vaccines because the risks of using MMRV vaccine in this group of children generally outweigh the benefit of MMRV vaccine.
What should I do if a patient has a clinically significant adverse event following vaccination?
The National Childhood Vaccine Injury Act (NCVIA) requires healthcare providers to report: any adverse event listed by the vaccine manufacturer as a contraindication to further doses of the vaccine; or any adverse event listed in the VAERS Table of Reportable Events Following Vaccination [5 pages] that occurs within the specified time period after vaccination.
Healthcare providers are encouraged to report other clinically significant adverse events that follow immunization to the Vaccine Adverse Event Reporting System (VAERS), even if they are unsure whether the event was caused by vaccine.
There are two ways to report to VAERS:
- Submit a VAERS report online.
- Using a Writable PDF form
If you need further assistance with reporting to VAERS, please email info@VAERS.org or call 1-800-822-7967.