ArticleEuropean journal of clinical pharmacology2026
Most COVID-19 vaccine adverse events detected within 48 hours in Ethiopia: implications for cohort event monitoring efficiency in resource-limited settings.
Article in European journal of clinical pharmacology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
0 citing papers in PubMed.
No citing paper in PubMed yet.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
9 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundThe World Health Organization recommends cohort event monitoring with a 30-day follow-up period for vaccine safety surveillance in low- and middle-income countries (LMICs). However, in resource-limited settings, operational and logistical constraints necessitate evaluation of the efficiency and feasibility of this follow-up duration.
methodsWe conducted an analysis of a prospective active surveillance study of 10,948 adults who received the Pfizer COVID-19 vaccine in Ethiopia (August 2021-June 2022), using immediate observation and telephone follow-up on days 2, 4, 7, 14, 21, and 30.
resultsAmong 10,948 participants, 4,236 (38.7%; 95% CI: 37.8-39.6%) reported at least one adverse event following immunisation (AEFI), with 6,174 total events recorded. Of all events, 88.2% were detected within 48 h (1.8% immediate, 86.4% at day 2), while 11.8% were identified during subsequent follow-up between days 4 and 30. Seven reactogenic symptoms comprised 93.8% of AEFIs. No serious AEFIs or adverse events of special interest were identified. Over nine months, 138 healthcare professionals captured predominantly mild, expected reactions through extended surveillance.
conclusionsMost COVID-19 vaccine adverse events in Ethiopia occurred within 48 h of vaccination, empirically suggesting that extended full-cohort CEM could yield diminishing informational returns in low- and middle-income country settings. A hybrid surveillance approach combining intensive short-term active surveillance during the first 48 h, enhanced passive reporting, and sentinel hospital networks with adequate diagnostic capacity could offer a more sustainable and operationally realistic framework. These findings are offered as an evidence-based reference for national regulatory authorities planning or conducting emergency vaccine safety surveillance in comparable contexts, supporting a transition from product-centred extended monitoring towards patient-centred, resource-adapted pharmacovigilance. CLINICAL TRIAL NUMBER: Not applicable.
Indexed as
Identifiers
42493669What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.