MMRV (ProQuad, Merck) (vote)
 
Background
Individual vaccines for measles, mumps, and rubella were licensed in the United States in the 1960s, and the first combined MMR (MMR-II, Merck) vaccine was licensed in 1971. The vaccine against varicella (chickenpox) (Varivax, Merck) received FDA licensure in 1995. MMRV (ProQuad, Merck), the combination vaccine against all four diseases, was licensed in 2005. When ACIP initially recommended MMRV, consistent with ACIP’s general recommendations on the use of combination vaccines, use of MMRV was preferred over separate injections at the same visit (abbreviated MMR+V) for both the first and second dose to reduce the number of injections needed.

As MMRV became widely used, a small increased risk for febrile seizures was identified during the first two weeks after vaccination when MMRV was used (instead of MMR+V) for the first dose of these antigens given to children age 12 through 23 months. The risk was roughly 1 additional febrile seizure per 2,000 doses of MMRV, when compared to using MMR+V. There was no increased risk of febrile seizure after administering MMRV as a second dose, regardless of the age at administration. Febrile seizures may be triggered in young children by any cause of fever, are typically of short duration, and only a small minority of children who experience a febrile seizure go on to have long term problems. By age 5 years, 2–4% of children have had at least one simple febrile seizure, often due to early childhood infections and diseases.
 
Since 2010, to minimize the small risk of febrile seizure, CDC has recommended that a child receive separate injections of MMR+V for the first doses of these antigens, unless the parent or caregiver prefers the single MMRV injection. The National Immunization Survey (NIS) and state immunization information systems (IIS) indicate only about 15% of children younger than age 3 years receive their first dose as MMRV, while MMRV is used for about 75% of second dose vaccinations among children age 4 through 6 years.
 
The committee identified no new risks or issues with the current schedule (i.e., MMR+V preferred for dose 1, and either MMR+V or MMRV for dose 2). Discussions on September 18 centered around the well-defined small increased risk of febrile seizure with the first dose of MMRV compared to the benefits of allowing families the option to choose fewer injections. There was no discussion about the evidence that second doses of MMRV given at age 15 months or older have not been associated with an increased risk of febrile seizure compared to MMR+V.

ACIP voted (8 yes, 3 no, 1 abstain) to recommend that the pediatric vaccine schedule should be updated to reflect the following change:

• For measles, mumps, rubella and varicella vaccines given before age 4 years, the combined MMRV vaccine is not recommended.
• Children in this age group should receive separate measles, mumps, and rubella vaccine and varicella vaccine (MMR+V).

ACIP conducted two votes on adoption of this language into a VFC program resolution, which provides specific details on vaccines provided through VFC. At the end of September 18, the committee voted not to update the VFC program and continue to allow use of MMRV for VFC-eligible children younger than age 4 years. The morning of September 19, the chair acknowledged that the committee did not understand what they were voting for. They then conducted a second vote on this topic to reverse the previous vote. ACIP voted a second time (9 yes, 3 abstain) to update the VFC resolution to remove MMRV as an option for vaccination of VFC-eligible children younger than age 4 years, aligning the VFC program with the committee’s recommendation.

HepB Birth Dose (vote)
 
Background
An estimated 2.4 million people in the United States are chronically infected with hepatitis B virus (HBV), half of whom are unaware of their infection. HBV is transmitted through contact with infected blood or body fluids or through contact with environmental surfaces contaminated by even microscopic amounts of infected blood or body fluids. The virus can remain viable on surfaces for up to 7 days after leaving the body.
 
Babies born to HBV-infected mothers have up to an 85% chance of acquiring HBV infection without intervention (ideally, HepB vaccination and administration of hepatitis B immune globulin [HBIG] within the first 12 hours of life). If infected, 90% will develop chronic HBV infection, and 25% will die prematurely due to cirrhosis or liver cancer. Administration of HBIG and a birth dose (within 24 hours) of HepB reduces the risk of mother-to-child transmission by approximately 94%. A dose of HepB alone within 24 hours of birth reduces the risk of infection by about 75%.

In 1991, CDC adopted a policy of routine infant vaccination, with a preference for vaccination at birth. By 2005, a routine birth dose (defined as vaccination before discharge from the birthing facility) was recommended. In 2018, CDC published the revised ACIP recommendation for the routine birth dose to be administered within 24 hours of life to optimize protection of newborns with unrecognized perinatal exposure to HBV. In 2021, CDC estimated that almost 18,000 infants were born to HBV-infected mothers in the United States. (Not stated in the meeting, but to demonstrate the success of this strategy: in 2020, just ten cases of perinatal HBV infection were reported to CDC.)
 
During the meeting, CDC experts presented the history and safety of hepatitis B birth dose vaccination. Anaphylaxis was described as the primary demonstrated risk of birth dose HepB, stated as occurring with a frequency of about 1.1 cases per 1 million birth doses administered. Anaphylaxis is extremely rare and can occur with any vaccination at any age.
 
The committee proposed a vote to recommend that the first dose of HepB for infants born to test-negative mothers not be given earlier than one month of age. The committee did not describe any specific problem with the current schedule as a rationale for proposing this change.

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September 28 is World Rabies Day. This date marks the anniversary of the death of Louis Pasteur, the French chemist and microbiologist who developed the first rabies vaccine. Around the world, about 59,000 people each year die of rabies, 40% of whom are children. Most rabies deaths globally occur as the result of dog bites.

Established by the Global Alliance for Rabies Control and recognized by the World Health Organization, this year's theme is "Act Now: You, Me, Community." This highlights the need for worldwide elimination of rabies transmission from dogs to humans, a goal already achieved in most countries in the Americas, including the United States. Rabies can still be found in wild mammals in the United States (e.g., bats, skunks, raccoons). Vaccination of pets and people at elevated risk remains essential to prevent transmission of the virus.

Use the 2022 ACIP recommendations for rabies prophylaxis to guide who should receive this vaccine. Rabies vaccination is indicated before any potential exposure for certain people whose work or recreational activities put them at increased risk of exposure to rabies. Rabies vaccination for post-exposure prophylaxis (PEP) is also recommended for any person after a possible or confirmed exposure to rabies. Consultation with local or state public health experts is recommended when evaluating the need for PEP.

You can help prevent rabies by keeping household animals up to date on rabies vaccination and collaborating with animal health advocates and policymakers in your community to raise awareness about rabies prevention.

Access the World Rabies Day website for more information.

Related Links

• Immunize​.org: Vaccines A–Z: Rabies web page
• Institut Pasteur: Pasteur Museum (Musée Pasteur) website

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