**4. Conclusions**

The importance of integrating routine immunization into primary healthcare systems has never been clearer. As countries continue to recover and adopt lessons from the last few years, to not only mitigate the effects of backsliding but to reach those who were previously unreached, integrated and holistic PHC systems offer the best way forward for supporting resilient and sustainable routine immunization programs. Investing in broader health system strengthening and improving linkages with communities will help advance immunization goals. With the future of the COVID-19 pandemic remaining uncertain, it is vital to focus on building back better the resilience of our immunization systems to respond more rapidly and effectively to challenges, and ensure all children continue to have access to lifesaving vaccinations despite new and emerging concerns. Learnings from the exemplary countries presented in this article provide insights into the various possibilities that can be unlocked with the right commitment and support.

**Supplementary Materials:** The following supporting information can be downloaded at: https: //www.mdpi.com/article/10.3390/vaccines11020375/s1, File S1: Enablers for RI Recovery in CHAI focal countries.

**Author Contributions:** Conceptualization, writing—original draft preparation, A.A. and T.A.; Resources—F.M., F.L., S.B., O.G., S.M. and N.N.E.; Supervision—L.B. All authors have read and agreed to the published version of the manuscript.

**Funding:** The development of this commentary received no additional external funding, however the CHAI-supported work highlighted in this article was made possible through funding from Bill & Melinda Gates Foundation and Gavi, the Vaccine Alliance.

**Institutional Review Board Statement:** Not applicable. This work reports on country-level program policies and is not considered human subjects research.

**Informed Consent Statement:** Not applicable. This work reports on country-level program policies and is not considered human subjects research.

**Data Availability Statement:** No new data were created or analyzed in this study. Data sharing is not applicable to this article.

**Acknowledgments:** Many thanks to CHAI country team colleagues from Cambodia, Cameroon, Kenya, Nigeria, and Uganda, who provided insights during this commentary development. We extend our gratitude and appreciation to our Ministry of Health counterparts and health partners in countries who continue to make significant progress in immunization access.

**Conflicts of Interest:** The authors declare no conflict of interest.
