A narrative review of pneumococcal serotypes causing invasive disease in North Africa and the Middle East

Introduction

Invasive pneumococcal disease (IPD) poses an enormous burden for developing countries. The introduction of pneumococcal conjugate vaccines (PCVs) has resulted in global declines in invasive pneumococcal disease (IPD), and the World Health Organization recommends PCV inclusion in all national immunization programs (NIPs). This review assesses the pneumococcal serotypes causing IPD in North Africa and the Middle East and the potential prevention of IPD by different serotype-specific PCVs.

Methods

A search was conducted in PubMed for articles published from 2012 to 2025 evaluating the serotypes causing IPD in North Africa and the Middle East.

Results

Of 263 articles retrieved, the 30 that met inclusion criteria investigated IPD in 10 countries from 1994 through 2022: Algeria, Iran, Jordan, Kuwait, Lebanon, Morocco, Oman, Qatar, Saudi Arabia, and Tunisia. The studies showed that the serotypes most responsible for IPD varied widely over time and across countries and often demonstrated an inverse relationship to vaccine uptake. The most common IPD-causing serotypes were 14 (≤57.0 %), 19A (≤46.2 %) and 19F (≤30.8 %), but the prevalence of serotypes 14, 19A, and 19F tended to decline after the introduction of 7-valent PCV and 13-valent PCV (PCV13) into NIPs. In contrast, percentages of IPD caused by non-vaccine serotypes remained high in some countries.

Discussion

Although limited data and variable results made major serotype distribution trends difficult to determine, IPD caused by PCV13 serotypes clearly declined after vaccine introduction whereas IPD caused by serotypes not included in the available vaccines tended to remain high or increase.

Conclusion

In North Africa and the Middle East, improved IPD serotype surveillance is needed. The introduction of higher valency vaccines into regional NIPs may alleviate IPD burden.