Methods: The ZSFG Children’s Health Center (CHC) provides primary, specialty, and PUC services to an urban, under-served community. In July 2020, CHC’s PUC began offering routine immunizations. Patients presenting to CHC between September 2019- February 2020 (baseline) and September 2020 – February 2021 (intervention) were included. Patient volume and vaccine doses were measured for all CHC clinics. Missed opportunities to vaccinate (MOs, defined as ≥1 vaccine due at patient checkout) and patient demographics were monitored in PUC during the intervention period.

Results: PUC-administered vaccination increased seven-fold over baseline (40 to 285 doses, excluding influenza); increases were observed for all vaccine types. Vaccinations administered in non-PUC CHC clinics decreased by 9.1% over the same period; decreases were observed for all vaccine types. The fraction of CHC vaccine doses administered in PUC increased from 0.4% to 3.5%, with particularly large increases among adolescent vaccines (TDaP, MMV4, and HPV 13.6%, 12.6%, 10.2%, respectively). MOs were observed in 380 PUC visits (21.2% of visits). Age >10 years, Latino identification, and care by attendings were associated with fewer MOs (18.6% v 26.6% p<0.001, 19.2% v 26.3% p=0.001, 17.5% v 22.5%, p=0.022, respectively).

Conclusion: PUC centers that share records with primary care clinics can improve access to childhood immunization during pandemics, particularly for adolescents. Additional research is needed to determine the generalizability of our findings.