The MMRV vaccine is a combination vaccine that protects against measles, mumps, rubella, and chickenpox in one shot. In the United States, the only licensed MMRV vaccine is ProQuad, approved for children 12 months through 12 years of age.
According to the CDC and ACIP, MMRV can be used for children starting at 12 months, but separate MMR and varicella vaccines are preferred for the first dose between 12 and 47 months due to a higher risk of fever-related seizures. MMRV is generally recommended for the second dose at 4 to 6 years, when this risk is lower.
The vaccine offers strong and lasting protection, helping prevent four highly contagious illnesses that can lead to serious complications. Understanding how the MMRV vaccine is used, who should receive it, and its possible side effects is important for following the US childhood immunization schedule
What is the MMRV vaccine?
The MMRV vaccine is designed to protect against viruses that cause highly contagious diseases, including measles, mumps, rubella, and chickenpox. It contains weakened live forms of these viruses. While they cannot cause the diseases themselves, they stimulate the immune system to build long-term protection.
The MMRV vaccine can be administered either under the skin (subcutaneous) or into the muscle (intramuscular), usually in the arm or thigh. For children with bleeding disorders or thrombocytopenia, the subcutaneous route is preferred.
Latest US guidance
In September 2025, ACIP recommended using separate MMR and varicella vaccines for the first dose in children 12 to 47 months because MMRV has a higher risk of fever-related seizures in this age range. MMRV is generally preferred for the first dose in children 48 months and older and for any second dose from 15 months through 12 years.
Brand names
Only one MMRV vaccine is licensed in the United States for children 12 months through 12 years: ProQuad, manufactured by Merck. MMR vaccines used with separate varicella as alternatives include M-M-R II and PRIORIX.
Vaccination schedule (USA)
The schedule below summarizes routine timing and product choices for children. Providers may adjust timing for catch-up vaccination using minimum intervals and clinical judgment.
Minimum intervals and administration: MMR doses must be separated by at least 28 days if not given on the same day. Two MMRV doses should be at least 3 months apart in children under 13 years. MMRV, MMR, and varicella may be given subcutaneously or intramuscularly according to current labeling and CDC guidance.
Safety and side effects
Common side effects after receiving the MMRV vaccine include mild fever, pain, redness, itching, or tenderness at the injection site. In rare cases, stronger reactions may occur, such as fever, rash, itching, or body aches.
Although the vaccine contains trace amounts of egg protein, no adverse reactions have been reported in people with egg allergies who received it. Most side effects resolve within a few days. If symptoms become more intense or persist, a pediatrician should be consulted.
When not to take it
The MMRV vaccine should not be given to children who are allergic to neomycin or any other component of the vaccine, who have received a blood transfusion within the past 3 months, or who have severely weakened immune systems due to conditions like HIV or cancer.
Vaccination should also be postponed if the child has a high fever caused by an acute infection. However, it can still be administered in cases of mild illness, such as a cold.
The vaccine is also not recommended for people undergoing treatments that weaken the immune system or for pregnant women.
Additional US precautions and delays
MMRV is not used in adults, since it is licensed only through 12 years, and adults who need protection receive separate MMR and varicella vaccines. Vaccination may be delayed after recent immunoglobulin or certain blood products, and after high-dose immunosuppressive therapy, based on CDC catch-up and precautions guidance.
FAQ
Some questions many patients have regarding the MMRV vaccine include:
1. Is MMRV vaccine safe for children under 2?
Yes, MMRV is licensed from 12 months of age, but CDC recommends separate MMR and varicella for the first dose at 12 to 47 months to reduce febrile seizure risk.
2. How much risk of febrile seizures with MMRV vs separate vaccines?
For the first dose at 12 to 23 months, MMRV roughly doubles the risk compared with separate vaccines, corresponding to about one extra febrile seizure per 2,300 to 2,800 doses.
3. How many shots will my child need?
Children need two doses in total. Depending on age and setting, this can be given as separate MMR plus varicella or as MMRV.
4. Can MMRV be used for the second dose later than 4 to 6 years?
Yes, the second dose can be given earlier or later as long as minimum intervals are met and it occurs from 15 months through 12 years.
5. What if my child missed a dose?
The series does not need to be restarted. Providers follow catch-up guidance using minimum intervals for MMR and MMRV.
6. Can adults get MMRV, or is it only for children?
MMRV is only for children 12 months through 12 years. Adults receive separate MMR and varicella vaccines if indicated.
7. Will insurance cover MMRV vaccine in the US?
MMRV is part of the routine childhood immunization schedule and is typically covered by insurance, with additional access through the Vaccines for Children program for eligible families.