1.) Which single design limitation most threatens valid estimates of sensitivity and representativeness? How would you address it within six weeks?
Relying only on passive facility-based reporting threatens sensitivity and representativeness.
Within 6 weeks,
My plan is to combine passive and active surveillance methods.
Firstly, I will select sentinel sites for passive and active surveillance.
Train focal persons the reporting procedure for AEFI (the timing, interval, variable, channels) and close follow-up for support.
Additionally, the focal persons will conduct phone call follow-ups to caregivers of children after 7 days of vaccination to capture unreported events.
I will follow up with the focal persons about the reporting flow/active tracing flow and adjust when necessary.
I will review weekly data and conduct evaluation in 6 weeks.
2.) Using the CDC surveillance attributes, propose one low-cost intervention to increase sensitivity. State the expected trade-offs, and list 2–3 indicators to detect impact from the intervention.
Low cost intervention – 7-day post vaccination follow ups with phone call at sentinel sites
CDC attributes addressed:
Sensitivity – capture more AEFI cases through active follow-ups
Timeliness- timely detection of any adverse effect
Acceptability – simple methods, easy to use
Trade-offs- More workload and burden to staff, phone bill costs, more false positives
Indicators –
1.AEFI reports/ 100,000 doses
2. % of AEFI cases detected through active phone call follow-ups
3. % of serious events detected within 48 hr
3.) For a newly introduced vaccine, should the AEFI case definition be temporarily broadened to maximize early signal detection?
– If yes, what trigger would you use to revert to the prior definition?
– If no, why should this change not be implemented?
Yes, the AEFI case definition should be temporarily broadened to maximize early signal detection.
When to revert – after 3 months and there is no new safety signal detected