At what age are MMR and Varicella vaccines first given?

At what age are MMR and Varicella vaccines first given?

• A. 2 months
• B. 6-9 months
• C. 12-15 months
• D. 4-6 years

Answer: (C)

Vaccine timing hinges on when the immune system can respond effectively and when maternal antibodies have waned. For MMR and Varicella, the first doses are given at 12 to 15 months. At this age, maternal antibodies to these viruses have decreased enough to allow the vaccines to provoke a strong and lasting immune response with good safety. Giving them earlier, such as at 2 months or 6–9 months, isn’t effective because maternal antibodies can interfere with the vaccine. The second doses are scheduled later, at 4–6 years, to boost immunity and help ensure long-term protection.

Vaccine timing hinges on when the immune system can respond effectively and when maternal antibodies have waned. For MMR and Varicella, the first doses are given at 12 to 15 months. At this age, maternal antibodies to these viruses have decreased enough to allow the vaccines to provoke a strong and lasting immune response with good safety. Giving them earlier, such as at 2 months or 6–9 months, isn’t effective because maternal antibodies can interfere with the vaccine. The second doses are scheduled later, at 4–6 years, to boost immunity and help ensure long-term protection.