What should be done for a 12-week-old infant who received the first dose of the DTap (Diphtheria, Tetanus, and Pertussis)/ipv (inactivated poliovirus)/hib (Haemophilus influenzae type b), hepatitis combined vaccine as per the NHS protocol in one location and is now in another location?

Continuing Vaccination After Relocation

Continue the vaccination series according to the current location's schedule without repeating the first dose, as interrupted or delayed vaccination series do not require restarting. 1

Core Principle: No Need to Restart Series

• Vaccination series interrupted by relocation should be continued at the next clinic visit without repeating doses. 1
• The specific brand or formulation used for the first dose does not necessitate restarting, though using the same manufacturer's product throughout is preferred when feasible. 2
• Any valid dose of DTaP-containing combination vaccine counts toward completion of the series, regardless of where it was administered. 2

Recommended Action at 12 Weeks

At 12 weeks of age, administer the second dose of the DTaP/IPV/Hib/Hepatitis B combination vaccine series according to the standard schedule. 3

Standard Timing for Second Dose:

• The second dose should be given at approximately 2 months (8 weeks) of age, with a minimum interval of 4 weeks between doses. 2, 3
• Since this infant is already 12 weeks old, the second dose should be administered immediately at the current visit. 3
• The minimum age for DTaP, IPV, and Hib vaccines is 6 weeks, which this infant has exceeded. 3

Complete Vaccination Schedule Going Forward

Remaining Primary Series:

• Third dose at 6 months of age (minimum 4-week interval from second dose, though 8 weeks is preferred). 2
• Fourth dose (booster) at 15-18 months of age (minimum 6 months after third dose). 4, 2
• Final DTaP dose at 4-6 years of age. 2

Component-Specific Considerations:

Hepatitis B:

• The second dose should be given at 1-2 months of age (already overdue at 12 weeks). 2
• The third dose must be administered at ≥24 weeks of age with at least 8 weeks after the second dose. 2

Hib:

• If using PRP-OMP conjugate (PedvaxHIB), only 2 primary doses are needed at 2 and 4 months, followed by a booster at 12-15 months. 1, 2
• If using HbOC or PRP-T conjugates, 3 primary doses are needed (2,4,6 months) plus booster at 12-15 months. 2
• The booster must be given at least 2 months after the last primary dose. 2

IPV:

• Four total doses are recommended at 2,4,6-18 months, and 4-6 years. 2
• Minimum 4-week intervals between doses are acceptable for catch-up schedules. 2

Critical Timing Considerations

Rotavirus Vaccine Window:

• If rotavirus vaccine was not given with the first dose, it can still be initiated up to 12 weeks of age. 3
• At exactly 12 weeks, this is the last opportunity to start the rotavirus series. 3
• The first dose must be given between 6-12 weeks; the series cannot be started after 12 weeks of age. 2, 3

Interchangeability of Vaccines

• Different brands of DTaP-containing combination vaccines can be used interchangeably to complete the series. 2, 1
• While using the same manufacturer's product throughout is preferred, vaccination should not be delayed if the original brand is unavailable. 2
• Any inadvertently administered dose (even if wrong brand or given at >5 years) should be counted as valid. 2

Documentation and Monitoring

• Obtain complete vaccination records from the NHS location to verify the exact vaccine product and date of first dose. 2
• Local reactions (pain, redness, swelling) increase with subsequent doses, particularly after the 4th and 5th doses, primarily due to the pertussis component. 5
• Monitor for increased local reactions at the injection site, which are typically mild and self-limited. 5