Related Experiment Video
Updated: Feb 28, 2026
Opsono-Adherence Assay to Evaluate Functional Antibodies in Vaccine Development Against Bacillus anthracis and Other Encapsulated Pathogens
Published on: May 19, 2020
Emergency department attendance following 4-component meningococcal B vaccination in infants
Sarah Kapur1, Thomas Bourke2, Julie-Ann Maney3
1Department of Paediatric Infectious Diseases, Royal Belfast Hospital for Sick Children, Belfast, UK.
Insights
Fever after the 4-component meningococcal B vaccine (4CMenB) in infants is common, but serious bacterial infections are rare. Further research is needed to guide management and potentially reduce invasive testing in post-vaccination fever cases.
Area of Science:
- Pediatrics
- Immunology
- Public Health
Background:
- The UK introduced the 4-component meningococcal B vaccine (4CMenB) in 2015.
- Fever is a known side effect of 4CMenB in infants.
- Fever in young infants raises concerns for serious bacterial infection (SBI).
Purpose of the Study:
- To audit the management of infants presenting with symptoms after 4CMenB vaccination.
- To assess the incidence of serious bacterial infection in infants with post-vaccination fever.
- To inform national guidelines for managing fever in infants post-4CMenB vaccination.
Main Methods:
- Prospective audit of infant (30-180 days) emergency department attendances in Northern Ireland.
- Data collected within 4 days of 4CMenB vaccination.
- Review of clinical presentation, investigations, and diagnoses.
Main Results:
- 0.8% of vaccinated infants attended the emergency department post-vaccination.
- 80% of infants presented with fever; 62% had blood tests.
- All cultures were negative; 100% of diagnoses were vaccine-related, with 51% hospital admissions.
Conclusions:
- Post-vaccination fever in infants receiving 4CMenB is common, with a low risk of SBI.
- Current investigation and management strategies may need re-evaluation for this population.
- Further data can support less-invasive approaches for managing fever after 4CMenB vaccination.
Introduction:
In September 2015, the UK became the first country in the world to introduce the 4-component meningococcal B vaccine(4CMenB) into the routine vaccine schedule for infants. 4CMenB is known to cause fever in infants. Infants presenting with fever, particularly those under 3 months, have a significant risk of serious bacterial infection(SBI).
Method:
Between September 2015 and January 2016, we performed a prospective audit of management of infants between 30 and 180 days attending the regional paediatric emergency department(ED) in Northern Ireland, within 4 days of receiving 4CMenB.
Results:
35 ED attendances in infants aged 30-180 days were due to symptoms occurring after primary vaccinations including 4CMenB, representing an estimated 0.8% of the vaccinated population in the catchment area. 86% of infants presented after the first vaccine and parents reported giving paracetamol to 94% of infants. 80% of infants presented with fever. Blood tests were performed in 62% of infants and leucocytosis was present in 73%. All cultures taken were negative and 51% were admitted to hospital. 100% of final diagnoses were vaccine related (diagnosis made by exclusion).
Discussion:
In this study, an estimated 0.8% of the vaccinated population in the catchment area attended ED with symptoms occurring after primary vaccinations including 4CMenB. Infants with fever have a higher risk of SBI, but infants with fever in the post-vaccination period may not have the same risk. Further data are essential to inform national guidelines on investigation and management of fever in infants following vaccination with 4CMenB, possibly incorporating a less-invasive approach.
More Related Videos
Related Concept Videos
01:51Vaccinations
01:29Drug Dosing: Infants and Children