4CMenB (Bexsero) Administration in the UK
Route and Dose
4CMenB (Bexsero) is administered intramuscularly at a dose of 0.5 mL per injection, which means a 4 mL vial would contain 8 doses. 1, 2
Route of Administration
- Intramuscular (IM) injection is the only approved route for 4CMenB administration 1, 2
- The preferred injection site varies by age:
Dose Volume
- Each dose is 0.5 mL regardless of age 1, 2, 3
- A 4 mL vial therefore contains 8 individual doses of 0.5 mL each 1
UK-Specific Dosing Schedule
The UK implemented a reduced 2-dose infant priming schedule that differs from other countries 4, 3:
- Primary series: 2 doses at 8 weeks and 16 weeks of age 4, 3
- Booster dose: 1 dose at 12 months of age 4, 3
This reduced schedule achieved 95.5% coverage for one dose and 88.6% for two doses by 6 months of age, with demonstrated effectiveness of 82.9% against all MenB cases 3.
Important Clinical Caveats
- The UK schedule differs from US recommendations, where 4CMenB is only licensed for ages 10-25 years with different dosing intervals 5, 6
- Fever is common when 4CMenB is co-administered with routine infant vaccines, occurring in approximately 40% of recipients 2
- Persistent injection site nodules were reported in 160 cases during UK surveillance, though typically without other concerning symptoms 2
- Each dose must be the full 0.5 mL volume - partial doses are not recommended and would compromise immunogenicity 1, 3