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Date of last update: 9/9/2017.

Forum Name: Pediatric Topics

Question: MMR and varicella vaccines

 asianwanderer - Sun Mar 16, 2008 1:00 pm

I understand that MMR vaccine and varicella vaccine can be given at the same time, otherwise, they can be given at least 4 weeks apart. What would happen if they were not given at the same time and was given less than 4 weeks apart?
 Dr. Chan Lowe - Mon Mar 17, 2008 2:03 pm

User avatar Hello Asianwanderer,

You are correct that the recommendation is that the MMR and the varicella vaccines either be given at the same time or separated by at least 4 weeks. The reason is that these viruses are a little different than other viruses. They are live virus vaccines in which the virus has been altered to be weaker so the virus can be fought off by the body without causing the disease.

The concern about giving them separately too close together is that the body may be distracted by the first vaccine while it tries to fight off the virus and may not react strongly enough to provide good immunity.

Best wishes.
 asianwanderer - Mon Mar 17, 2008 9:48 pm

Dr. Lowe,

If MMR and varicella vaccines were given separately too close together (less than 4 weeks apart) then what do you suggest for this patient?

Thank you.
 Dr. Chan Lowe - Tue Mar 18, 2008 10:10 pm

User avatar Hello again,

If the doses were too close together, the recommendation is to disregard the second vaccine and redose it once the appropriate time has past. The repeated dose is not dangerous and will ensure proper immunity is obtained.

Best wishes.

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