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. 2024 Mar 8;10(6):e27464.
doi: 10.1016/j.heliyon.2024.e27464. eCollection 2024 Mar 30.

Surveillance of COVID-19 vaccines: A comprehensive analysis of the first immunization drive in Ecuador

Andrea Orellana-Manzano  1 , Andrea C Garcia-Angulo  2 , Fernanda B Cordeiro  1 , Diana Carvajal-Aldaz  1 , Elizabeth Centeno  3 , María J Vizcaíno  1 , Sebastián Poveda  2 , Merly Garcia  1 , Carmen Matías-De la Cruz  1 , Derly Andrade-Molina  4 , Mariuxi Mirabá  1 , Saurabh Mehta  3 , Washington B Cárdenas  1
Affiliations

Surveillance of COVID-19 vaccines: A comprehensive analysis of the first immunization drive in Ecuador

Andrea Orellana-Manzano et al. Heliyon. .

Abstract

The initial phase of the COVID-19 vaccination in Ecuador occurred between April and November 2021. Initially, it focused on priority populations, including health professionals and other front-line workers. During this period, there was limited knowledge about the vaccine's adverse effects. A non-probability, observational study was conducted among university staff in Guayaquil, Ecuador, who received the AstraZeneca vaccine (n = 423) between April and November 2021. This study aimed to compare the acute adverse reactions by doses and to report the incidence of long-term adverse reactions within the AstraZeneca group. As a result, comparing acute adverse reactions between doses, the odds ratio for local pain, headache, muscle pain, fever, and chills are statistically higher after the first dose than the second dose. Survival curves indicated these symptoms appeared mainly within the first 6 h post-vaccination. This is the first pharmacovigilance study from Ecuador that analyzes survival probabilities for the AstraZeneca vaccine's adverse effects.

Keywords: AstraZeneca; COVID-19; Ecuador; Immunization; Vaccine; pharmacovigilance.

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Conflict of interest statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Figures

Fig. 1
Fig. 1
Pharmacovigilance vaccination study design for AstraZeneca cohort.
Fig. 2
Fig. 2
Acute adverse effects reported after the first and second doses of the AstraZeneca vaccine.
Fig. 3
Fig. 3
Survival curves for most common adverse effects after the first and second dose of AstraZeneca Vaccine accounting for the effect of taking medicine. A. Local pain overall survival probability. B. General tiredness overall survival probability; C. Headache overall survival probability; D Muscle pain overall survival probability; E. Chills overall survival probability. F. Fever overall survival probability.
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