Peer-reviewed article
Safety of Co-Administration Versus Separate Administration of the Same Vaccines in Children: A Systematic Literature Review
Jorgen Bauwens, Luis-Henri Saenz, Annina Reusser, Nino Künzli, Jan Bonhoeffer ·
Summary
Written by AI, not yet AICS's view · claude-haiku-4-5-20251001This systematic review examined 50 studies published between 1999 and 2019 comparing the safety of giving multiple vaccines at the same time versus giving them separately in children. Most studies found no significant differences in adverse events between co-administration and separate administration of vaccines. However, the overall evidence was inconclusive because many studies had poor quality reporting and lacked proper statistical analysis of adverse events.
Key points
- 16% of studies (8 out of 50) reported significantly more adverse events with co-administration
- 10% of studies (5 out of 50) found significantly fewer adverse events with co-administration
- Statistically significant differences were found for 16 adverse events across 11 different vaccine combinations
- One-third of studies lacked any statistical assessment of adverse events
- Most commonly studied vaccines included MenACWY, DTaP, MMR, and pneumococcal vaccines
Limitations
The document does not provide details on the types or severity of adverse events reported, nor does it evaluate the clinical significance of the differences found. The review does not assess effectiveness of vaccines, only safety outcomes, and notes the paucity of large post-licensure studies.
Abstract
The growing number of available vaccines that can be potentially co-administered makes the assessment of the safety of vaccine co-administration increasingly relevant but complex. We aimed to synthesize the available scientific evidence on the safety of vaccine co-administrations in children by performing a systematic literature review of studies assessing the safety of vaccine co-administrations in children between 1999 and 2019, in line with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Fifty studies compared co-administered vaccines versus the same vaccines administered separately. The most frequently studied vaccines included quadrivalent meningococcal conjugate (MenACWY) vaccine, diphtheria and tetanus toxoids and acellular pertussis (DTaP) or tetanus toxoid, reduced diphtheria toxoid and acellular pertussis (Tdap) vaccines, diphtheria and tetanus toxoids and acellular pertussis adsorbed, hepatitis B, inactivated poliovirus and Haemophilus influenzae type b conjugate (DTaP-HepB-IPV/Hib) vaccine, measles, mumps, and rubella (MMR) vaccine, and pneumococcal conjugate 7-valent (PCV7) or 13-valent (PCV13) vaccines. Of this, 16% (n = 8) of the studies reported significantly more adverse events following immunization (AEFI) while in 10% (n = 5) significantly fewer adverse events were found in the co-administration groups. Statistically significant differences between co-administration and separate administration were found for 16 adverse events, for 11 different vaccine co-administrations. In general, studies briefly described safety and one-third of studies lacked any statistical assessment of AEFI. Overall, the evidence on the safety of vaccine co-administrations compared to separate vaccine administrations is inconclusive and there is a paucity of large post-licensure studies addressing this issue.
Findings the Hub has extracted
Each claim below is labelled by its type of design and links back to this report.
- Intervention
- Co-administration of the same vaccines (given simultaneously) versus separate administration (given at different times)
- Population
- Children aged 0-18 years receiving routine vaccinations
Key finding
8 studies (16%) reported significantly more adverse events with co-administration