The immune status of migrant populations in Europe and implications for vaccine-preventable disease control: a systematic review and meta-analysis

Zeinab Cherri; Karen Lau; Laura B Nellums; Jan Himmels; Anna Deal; Emma McGuire; Sandra Mounier-Jack; Marie Norredam; Alison Crawshaw; Jessica Carter; Farah Seedat; Nuria Sanchez Clemente; Oumnia Bouaddi; Jon S Friedland; Michael Edelstein; Sally Hargreaves

doi:10.1093/jtm/taae033

The immune status of migrant populations in Europe and implications for vaccine-preventable disease control: a systematic review and meta-analysis

J Travel Med. 2024 Feb 29:taae033. doi: 10.1093/jtm/taae033. Online ahead of print.

Authors

Zeinab Cherri¹, Karen Lau^{1

2

3}, Laura B Nellums⁴, Jan Himmels¹, Anna Deal^{1

2}, Emma McGuire¹, Sandra Mounier-Jack², Marie Norredam^{5

6}, Alison Crawshaw¹, Jessica Carter¹, Farah Seedat¹, Nuria Sanchez Clemente¹, Oumnia Bouaddi^{3

7}, Jon S Friedland⁸, Michael Edelstein⁶, Sally Hargreaves^{1

3}

Affiliations

¹ The Migrant Health Research Group, Institute for Infection and Immunity, St Georges, University of London, London, UK.
² Department of Global Health and Development, Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London.
³ Lancet Migration European Regional Hub.
⁴ Faculty of Medicine and Heath Sciences, University of Nottingham, Nottingham UK.
⁵ Danish Research Centre for Migration, Ethnicity and Health, Section of Health Services Research, Department of Public Health, University of Copenhagen, Denmark.
⁶ Department of Infectious Diseases, Hvidovre Hospital, University of Copenhagen.
⁷ International School of Public Health, Mohammed VI University of Sciences and Health, Casablanca, Morocco, and Mohammed VI Center for Research and Innovation, Rabat, Morocco.
⁸ Institute for Infection and Immunity, St Georges, University of London, London, UK.

PMID: 38423523
DOI: 10.1093/jtm/taae033

Abstract

Background: Ensuring vaccination coverage reaches established herd immunity thresholds (HIT) is the cornerstone of any vaccination programme. Diverse migrant populations in European countries have been associated with cases of vaccine-preventable diseases (VPD) and outbreaks, yet it is not clear to what extent they are an under-immunised group.

Methods: We did a systematic review and meta-analysis to synthesise peer-reviewed published primary research reporting data on the immune status of migrants in EU/EEA countries, the UK and Switzerland, calculating their pooled immunity coverage for measles, mumps, rubella, and diphtheria using random-effects models. We searched on Web of Science, Embase, Global Health and MEDLINE (January 1st 2000 to June 10th 2022), with no language restrictions. The protocol is registered with PROSPERO (CRD42018103666).

Findings: Of 1103 abstracts screened, 62 met eligibility criteria, of which 39 were included in the meta-analysis. The meta-analysis included 75 089 migrants, predominantly from outside Europe. Pooled immunity coverage among migrant populations was well below the recommended HIT for diphtheria (n = 7, 57.4% [95% CI: 43.1-71.7%] I2 = 99% vs HIT 83-86%), measles (n = 21, 83.7% [95% CI: 79.2-88.2] I2 = 99% vs HIT 93-95%), and mumps (n = 8, 67.1% [95% CI: 50.6-83.6] I2 = 99% vs HIT 88-93%), and midway for rubella (n = 29, 85.6% [95% CI: 83.1-88.1%] I2 = 99% vs HIT 83-94%), with high heterogeneity across studies.

Interpretation: Migrants in Europe are an under-immunised group for a range of important VPDs, with this study reinforcing the importance of engaging children, adolescents, and adults in 'catch-up' vaccination initiatives on arrival for vaccines, doses, and boosters they may have missed in their home countries. Co-designing strategies to strengthen catch-up vaccination across the life-course in under-immunised groups is an important next step if we are to meet European and global targets for VPD elimination and control and ensure vaccine equity.