Vaccines Administered at 4-Year-Old Well-Child Visit
At the 4-year-old well-child visit, administer four core vaccines: the fifth dose of DTaP, the fourth dose of IPV, the second dose of MMR, and the second dose of varicella vaccine. 1
Core Vaccine Schedule
DTaP (Diphtheria, Tetanus, and Pertussis)
- Administer the fifth and final dose of DTaP at age 4-6 years to complete the childhood series. 2, 1
- This dose should not be given before age 4 years, though it can be administered as early as age 4 years if the child is unlikely to return for a later visit. 1
- The fourth dose may be given as early as 12 months if 6 months have elapsed since the third dose, but the fifth dose must wait until age 4-6 years. 2
- Vaccine effectiveness is 98.1% within the first year after this final dose. 1
IPV (Inactivated Poliovirus Vaccine)
- Give the fourth and final dose of IPV at age 4-6 years, completing the childhood polio vaccination series. 1
- This represents the final dose needed for routine childhood immunization against polio. 2
MMR (Measles, Mumps, and Rubella)
- Administer the second dose of MMR at age 4-6 years. 2, 1
- All children achieve seroprotective antibody levels for measles, mumps, and rubella after this second dose. 1
- The minimum interval from the first dose is 4 weeks, so MMR may be given earlier than age 4-6 years if at least 4 weeks have elapsed since the first dose. 2
Varicella Vaccine
- Give the second dose of varicella vaccine at age 4-6 years. 2, 1
- This dose significantly boosts immunity against chickenpox. 1
- The vaccine may be administered earlier than age 4-6 years if 2-3 months have elapsed since the first dose. 2
Practical Administration Strategies
Combination Vaccines to Reduce Injections
- DTaP-IPV combination vaccines (Kinrix or Quadracel) are preferred to reduce the number of injections from four to three. 1
- These combination vaccines have comparable safety and immunogenicity to separately administered DTaP and IPV vaccines. 2, 3
- Kinrix is specifically indicated for children aged 4-6 years who received Infanrix as their previous DTaP doses. 2
Simultaneous Administration
- All four vaccines (DTaP, IPV, MMR, and varicella) can and should be administered during the same visit. 1
- Concomitant administration does not interfere with immune responses to any of the vaccine antigens. 4, 5
- Co-administration of varicella vaccine with DTaP-IPV and MMR does not impact immunogenicity of any component. 4
Additional Vaccine Consideration
Influenza Vaccine
- Annual influenza vaccination is recommended for all children aged 6 months and older. 2, 1
- Children under 9 years who have received fewer than two lifetime doses of influenza vaccine need two doses given at least 4 weeks apart. 1
Important Clinical Caveats
Vaccine Manufacturer Consistency
- Whenever feasible, use the same manufacturer's DTaP vaccine throughout the series, but never delay vaccination if the previous manufacturer is unknown or unavailable. 2, 1
- Data are limited on safety and immunogenicity of interchanging DTaP vaccines from different manufacturers, but vaccination should not be deferred. 2
Timing Considerations
- The final DTaP dose should not be given before age 4 years. 1
- If DTaP-IPV is inadvertently administered for an earlier dose, the dose should be counted as valid if minimum interval requirements have been met. 2
Safety Profile
- The most common adverse reactions (≥5%) are crying, fever, and loss of appetite. 6
- Local reactions at injection sites include redness, slight pain, and hardness, with rates generally low across all doses. 6
- The tolerability profile of combination vaccines is comparable to separately administered vaccines. 3, 5