Background and objective:
The covid-19 pandemic has disrupted routine immunizations globally, with low-middle-income countries (lmics) struggling to achieve pre-covid-19 coverage rates. We leveraged real-time immunization records of >6.9m children from the government’s electronic immunization registry (seir) in sindh, pakistan, to quantify the pandemics 2-year impact on routine childhood immunizations, including the success and inclusiveness of catch-up strategies.

Methods:
We extracted individual immunization records from the seir from march 23, 2019➠to march 22, 2022. Comparing baseline (1-year preceding the first lockdown) and the 2-year covid-19 period, we analyzed the impact on daily immunization coverage rates and impact heterogeneity in coverage across gender and geographies. furthermore, we examined the success and inclusiveness of post-covid-19 catch-up strategies for missed children.

Results:
We found a 48% (21,440/45,024) and 89% (40,033/45,024) decline in the daily average number of vaccine doses administered during the first and second covid-19 lockdowns compared to the baseline. Immunizations declined more for girls vs. Boys and in slums and rural areas compared to non-slums and urban areas. Of the 3.8m children who missed immunizations during the 2-year covid-19 period, 76% (2,919,683/3,818,716) were covered at the two-year mark. Despite covid-19 disruptions, the daily average number of vaccine doses administered at the one- and two-year mark surpassed the baseline rates in sindh by 22% (10,063/45,024) and 21% (9,365/45,024). Moreover, the female-based gender equity improved at the 2-year mark (crude male-to-female ratio (m:f) =1:1.09) compared to baseline (crude m:f=1:1.10)

Conclusion:
Seir was crucial in supporting epi activities to trace, target and immunize children who missed immunizations during the 2-year covid-19 period. Pakistan is among the countries that successfully leveraged eirs during the pandemic to monitor immunization trends and transform data into actionable insights for evidence-based decision-making.