Abstract
Background: In August, 2015, the UK implemented an emergency adolescent immunisation programme with the meningococcal ACWY conjugate vaccine to combat a national outbreak of meningococcal group W (MenW) disease due to a hypervirulent ST-11 complex strain, which is currently causing regional and national outbreaks worldwide. This immunisation programme specifically targeted adolescents aged 13–18 years, an age group with low disease incidence but high nasopharyngeal carriage, with the aim of interrupting transmission and providing indirect (herd) protection across the population. Here, we report the impact of the first 4 years of the programme in England. Methods: Public Health England conducts meningococcal disease surveillance in England. Laboratory-confirmed cases of invasive meningococcal disease during the academic years 2010–11 to 2014–15 (Sept 1 to Aug 31) were used to predict post-vaccination trends, based on the assumption that cases would plateau 1 year after vaccine implementation (conservative scenario) or that cases would continue to rise for 4 years after vaccine implementation (extreme scenario). Vaccine uptake evaluated in August, 2019, was 37–41% in adolescents aged 18 years immunised in primary care and 71–86% in younger teenagers routinely vaccinated in school. Vaccine effectiveness was estimated with the indirect screening method. Findings: MenW and MenY cases plateaued within 12 months and then declined, while MenC cases remained low throughout. Significant reductions were observed among adolescents aged 14–18 years for MenW (incidence rate ratio [IRR] 0·35 [95% CI 0·17–0·76]) and MenY (0·21 [0·07–0·59]) cases, with a non-significant reduction in MenC cases (0·11 [0·01–1·01]). Based on conservative and extreme scenarios, 205–1193 MenW cases were prevented through the indirect effects of the programme and 25 through direct protection. For MenY, an estimated 60–106 cases were prevented through the indirect effects of the programme and 19 through direct protection. Ignoring any residual effect from an earlier MenC-containing vaccine, the overall vaccine effectiveness against MenCWY disease combined was 94% (95% CI 80–99). Interpretation: A meningococcal immunisation programme specifically targeting adolescent carriers succeeded in rapidly controlling a national MenW outbreak, even with moderate initial vaccine uptake. Funding: Public Health England.
| Original language | English |
|---|---|
| Pages (from-to) | 96-105 |
| Number of pages | 10 |
| Journal | The Lancet Child and Adolescent Health |
| Volume | 6 |
| Issue number | 2 |
| DOIs | |
| State | Published - Feb 2022 |
| Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2022
Funding
We thank local health protection teams, child health records departments, and general practitioners for their contribution to ascertaining vaccination status. We are also grateful to Sonia Ribeiro for IT support and to Paul Charter for clinical follow-up and data entry and the laboratory staff at the PHE meningococcal reference unit for contributions to national surveillance. This study did not receive any funding. The authors had sole responsibility for study design, data collection, data analysis, data interpretation, and writing of the report. All authors are employed by Public Health England, the study funder, which is a public body—an executive agency of the Department of Health.
| Funders | Funder number |
|---|---|
| Public Health England |
