The UK Health Security Agency (UKHSA) has issued updated national guidance for the hexavalent combination vaccine programme, confirming the transition to a four-dose routine schedule for children born since the summer of 2024.
The update, released on 18 September 2026, details the clinical requirements for the “6-in-1” vaccine, which provides essential protection against six serious childhood diseases: diphtheria, tetanus, pertussis (whooping cough), polio, Haemophilus influenzae type b (Hib), and hepatitis B.
Under the current national programme, infants receive primary doses at 8, 12, and 16 weeks of age. However, the 2026 guidance now fully incorporates the 18-month booster dose for all children born on or after 1 July 2024. This fourth dose is designed to provide longer-term protection as children move toward school age.
Parents and carers of children in this age group should expect to receive an invitation for the 18-month booster appointment from their GP surgery or local immunisation service. The 6-in-1 vaccine is considered highly effective, and the two brands currently approved for use in the UK—Infanrix hexa and Vaxelis—are interchangeable. This means a child can safely receive a different brand for their booster than they received during their initial primary course.
The selective neonatal pathway
The UKHSA guidance also clarifies the specific requirements for infants at higher risk of hepatitis B, such as those born to mothers who carry the virus. These infants follow a “selective neonatal pathway” which involves additional protection beyond the routine schedule.
In these cases, infants must receive monovalent (single-disease) doses of the hepatitis B vaccine at birth and at four weeks of age. This is then followed by the standard 6-in-1 vaccine doses at 8, 12, and 16 weeks, and the final booster at 18 months.
A critical part of this high-risk pathway is a blood test, known as a dried blood spot test, which must be carried out between 12 and 18 months of age. This test is used to check for the hepatitis B surface antigen to ensure the child has not developed a chronic infection.
Catch-up and eligibility
The UKHSA maintains that if a child misses any of their scheduled doses at 8, 12, or 16 weeks, they should be caught up as soon as possible, leaving a minimum interval of four weeks between doses.
While the 18-month booster is a new routine addition for those born from July 2024 onwards, the UKHSA guidance ensures that the clinical pathway is standardised across all NHS regions in England. There is no change to the advice regarding the safety of the vaccine; common side effects remain mild, typically including redness or swelling at the injection site, or a mild fever, which can be managed with infant paracetamol.
