01 kulldorff MMRV 508

CDC ACIP — Vaccine Advisory Committee

Acip

Slides

13

Document text

MMRV
MMRV = One combined shot for Measles, Mumps, 
Rubella and Varicella 
alternative to
MMR+V = Two shots, one for Measles, Mumps and 
Rubella and another for Varicella
No known difference in efficacy
 
MMRV Timeline
2005: FDA licensed the combined MMRV 
vaccine for use in children 12 months to 12 
years of age.
2006: The CDC Advisory Committee on  
Immunization Practices recommended use of 
MMRV, with preference over separate MMR 
and Varicella vaccines.
 

Weekly Safety Surveillance
CDC’s Vaccine Safety Datalink Rapid Cycle 
Analysis
Weekly Data from Electronic Health Records
First MMRV dose, at age 12 -23 months
2007: Signal for an excess number of febrile 
seizures after ~26,000 doses 
 
Seizure Signal
For 12 -23 month olds, 
seizure signal on February 
11, 2007. 
Cumulative doses at that 
time: 25,779
Observed Expected Relative 
RiskLLR (critical 
value)
Number 
Seizures 59 38 1.57 5.17 (4.12)
Note: No seizure risk after second dose at age 4 -6 years old 

Postvaccination seizures among 12 - to 23 -month -olds according 
to vaccine received: VSD study population, 2000 –2008.

Risk for Febrile Seizures after 
MMRV Compared to MMR+V

Also excess in post -vaccination fever

MMRV Working Group Vote
Four Options for the Vote, ages 12 -47 months:
1.Both recommended, Preference for MMRV
2.Both recommended, Equal preference
3.Both recommended, Preference for MMR+V
4.Only recommend MMR+V1. Zero votes
2. Minority
3. Majority
4. One vote
2009
ACIP Vote
Four Options for the Vote, ages 12 -47 months:
1.Both recommended, Preference for MMRV
2.Both recommended, Equal preference
3.Recommend both, Preference for MMR+V
4.Only recommend MMR+V1. Zero votes
2. Majority
3. Minority
4. Zero votesJune 2009

CDC 2009 Recommendation
ACIP is only advisory. CDC decided:
-Either MMRV or MMR+V may be 
administered
-For dose 1 in children age 12 -47 months, 
preference for MMR+V

Summary
-No known difference in efficacy between 
MMRV and MMR+V
-After first dose for children at ages 12 -23 
months, more febrile seizures after MMRV 
than MMR+V, ~ 1 per 2,300 doses
-After second dose at ages 4 -6 years, no 
excess risk for febrile seizures
Proposed Recommendation
As there exist a safer equally effective 
alternative, the MMRV vaccine should 
not be administered to children under 
the age of 47 months.