Evaluation of Sars-Cov-2 infection in vaccinated persons: Case of the general hospital of Douala (Cameroon)

Jean Pierre Nda-Mefo'o 1, 2, *, Marie Louise Njieme-Mefire 2, Charles Lebon Mbele-Onana 3, Elodie Ngo-Malabo 1, Grace Dalle-Ngondi 2, 4, Catherine Akono-Ndi 1, Bertrand Hugo Mbatchou-Ngahane 3, Henry Namme-Luma 3 and Cécile Okalla-Ebongue 1, 2

1 Clinical biology laboratory, Douala General Hospital, Cameroon.
2 Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Cameroon.
3 Department of Internal Medicine, Douala General Hospital, Cameroon.
4 Laboratory, Laquintinie Hospital, Douala, Cameroon.
 
Research Article
World Journal of Advanced Pharmaceutical and Life Sciences, 2022, 03(01), 013–019.
Article DOI: 10.53346/wjapls.2022.3.1.0036
Publication history: 
Received on 23 July 2022; revised on 30 August 2022; accepted on 01 September 2022
 
Abstract: 
Coronavirus infection is a public health problem worldwide despite the implementation of several control measures and vaccination. The purpose of this study was to evaluate SARS-Cov-2 infection in vaccinated patients.
Methods: A cross-sectional study was conducted at the Douala General Hospital from January to June 2022. Patients of both sexes, aged over 18 years, vaccinated against SARS-CoV-2 were included. Information regarding socio-demographic data, clinical manifestations, and SARS-CoV-2 vaccination was collected by individual interview. Nasopharyngeal secretions were collected by swabbing and transported to the laboratory. SARS-CoV-2 was detected using a rapid diagnostic test (antigen test) and a molecular test targeting the ORF and N genes (Daan gene® kit). Data were analyzed using StatView v5.0 and GraphPad v5.03.
Results: A total of 62 patients were selected and women represented 64.5%. The mean age of the patients was 45.58 ± 13.14 with a predominance of the 40 to 50 year old age group. The patients had been vaccinated with four SARS-CoV-2 vaccines (Vaxzeria®, Jcovden-COVID-19 Vaccine Janssen®, Comirnaty Biontech-Pfizer® and Sinovac®); 50.9% of them had received the Janssen®. Viremia was higher in men aged 30 to 60 years and in those who received Janssen® vaccine. The mild form of the infection was the most common clinical presentation with 80.4% of cases. There was a delay of 3 to 5 months between vaccine administration and COVID 19 infection.
Conclusion: Most of the vaccinated persons developed mild forms of COVID-19 with a mean delay of 3 to 5 months; the viremia was higher in men, in those who received the Janssen® vaccine and in those aged 30 to 60 years. Vaccination remains an effective means of preventing severe forms of SARSCoV-2 infection.
 
Keywords: 
COVID-19; Post-vaccination infection; Douala; Hospital
 
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