Acceptance of vaccination against COVID-19 among peritoneal dialysis patients in Senegal

Abstract

Introduction
The aim of this study was to assess vaccination coverage among peritoneal dialysis patients and to identify factors associated with non-vaccination.
Patients and methods
This was a multicenter, retrospective, descriptive, and analytical study conducted over a 6-month period in 4 peritoneal dialysis units. Patients on peritoneal dialysis for at least 3 months were included.
Results
Forty-nine patients were included in our study. Of these, 30 (61.2%) were vaccinated against COVID-19, with a sex ratio of 0.8. Eighty-three percent of patients had received 2 doses. Of these, 63.3% had received the AstraZeneca vaccine, 33.3% Sinopharm, and 3.4% Johnson & Johnson. Adverse events were mainly pain at the inoculation site in 100% of cases and influenza-like illness in 25%. The reason for non-vaccination in 42% of cases was fear of vaccine side effects and/or minimization of the severity of COVID-19. Among vaccinated patients, 2 (6.6%) had tested positive for COVID-19 after vaccination, including one with a severe form 3 months after vaccination. The average age of vaccinated patients was significantly higher (47.6 years) than that of non-vaccinated patients (37.6 years) (p=0.048).
Conclusion
It is vital to continue applying COVID-19 prevention measures in the various peritoneal dialysis centers, and to encourage vaccination or completion of vaccination schedules, particularly in younger patients.

Introduction

Severe Acute Respiratory Syndrome (SARS-CoV2), is a viral pneumonia secondary to CoronaVirus 2, a virus of the coronavirus family that was first isolated in Wuhan, China in December 2019. This virus, responsible for Coronavirus Disease 2019 (COVID-19) spread rapidly and the WHO declared a state of pandemic on 11 March 2020[1].

As of July 28, 2022, over 570 million cases of COVID-19 and more than 6.3 million deaths were recorded worldwide[2].

In Senegal, the first case of COVID-19 was diagnosed on March 2, 2020[3], and by July 28, 2022, over 87,000 cases of COVID-19 had been diagnosed and over 1,900 deaths recorded.

Faced with this pandemic, the scientific community was recommending a number of measures to curb the spread of the virus, including the mandatory wearing of masks, social distancing, hand washing, and the use of virucidal hydroalcoholic solutions[4].

At the same time, several countries began developing vaccines against SARS-CoV2, and vaccination has emerged as the best way to slow the spread of the virus.

As chronic kidney disease (CKD) is a high-risk area for COVID-19, patients on peritoneal dialysis (PD) and hemodialysis were targeted as a priority for the vaccination campaign.

The main aims of our study were to investigate vaccination coverage among peritoneal dialysis patients in Senegal, to assess the prevalence of COVID-19 among vaccinated peritoneal dialysis patients, and to identify factors associated with non-vaccination.

Patients and methods

Type and period

This was a multicenter, retrospective, descriptive, and analytical study with a period ranging fron the date of the start of vaccination in Senegal (February 23, 2021) to the end of August 2022 in 4 peritoneal dialysis units in Senegal.

Study population

We included all patients in PD for at least 3 months in Senegal.

Patients whose files were incomplete or who refused to answer the questionnaire were not included.

Data collection

Data were collected on a pre-established form. The survey form recorded the reasons for vaccination, the type and dose of vaccine, and any reasons for non-vaccination.

Definition of operating parameters

In our study, patients were considered to have had COVID-19 only when the diagnosis was made biologically by a positive RT-PCR (reverse-transcriptase polymerase chain reaction) or a positive antigenic test.

In addition, severity criteria from the Diagnosis and Treatment Protocol for Novel Coronavirus Pneumonia (Trial Version 7) were used. COVID-19 was considered mild when it was asymptomatic (no clinical signs) or only slightly symptomatic (asthenia). It was considered moderate when pulmonary clinical signs and fever were present but did not require hospitalization. Finally, it was considered severe in the presence of respiratory distress with tachypnea greater than 30 cycles per minute or oxygen saturation (SaO2) below 93%, requiring hospitalization in an intensive care unit[5].

Statistical analysis

Data were entered online on a Google Docs form and then exported to Microsoft Excel 2016. Data analysis was carried out using IBM SPSS (Statistical Package for the Social Sciences) 25. They were expressed using measures of central tendency and dispersion (mean ± standard deviation) for quantitative variables and frequencies for qualitative variables. To compare frequencies, we used Pearson’s chi-square test. Means were compared using the analysis of variance test. A p-value of less than 0.05 was considered significant.

Ethical considerations

The study protocol was submitted to the National Health Research Ethics Committee at the Ministry of Health and Social Action under reference SEN2022/110.

RESULTS

Epidemiological data

Of a total of 74 PD patients in Senegal, 49 were included in our study. The mean age of the patients was 43.7 ± 17.5 years. There were 24 men (49%) and 25 women (51%), giving a sex ratio of 0.96. The most frequent nephropathy was benign nephroangiosclerosis (NAS) in 32.7% of cases, followed by chronic glomerulonephritis (CGN) in 24.5%. In the remaining 32.7% of cases, the causative nephropathy was undetermined. The average length of time patients had been in PD was 18 ± 22.2 months. The majority of patients (81.7%) had been in PD for less than 18 months (Table I).

Table I.

Features		Averages and percentages
Age		43.7 ± 17.5
Sex	Male	24 (49%)
	Female	25 (51%)
Seniority in PD		18 ± 22.2
Causal nephropathy	Nephroangiosclerosis	16 (32.7%)
	Chronic glomerulonephritis	12 (24.5%)
	Diabetic nephropathy	3 (6.1%)
	Autosomal dominant polycystic fibrosis	1 (2%)
	Nephronophthisis	1 (2%)
	Undetermined	16 (32.7%)
Comorbidities	Hypertension	37 (75.5%)
	Diabetes	3 (6.1%)
	Obesity	2 (4.2%)

Vaccination against COVID-19

Vaccination coverage

Thirty patients (61.2%) were vaccinated against SARS-CoV2, while 19 patients (38.8%) were not.

Reason for non-vaccination

In 42% of cases of vaccine refusal, the reason for non-vaccination was both fear of vaccine side effects and minimization of the severity of COVID-19. Six patients (31.6%) refused the vaccine solely out of fear of side effects, and 5 patients (26.3%) refused the vaccine only because COVID-19 did not seem serious enough to warrant vaccination.

Reason for vaccination

All vaccinated patients (30) were vaccinated to protect themselves, and 27 patients (90%) were vaccinated to protect those around them. No patient was vaccinated because of an external obligation (international travel, obligation to be vaccinated in the workplace or for access to certain public places, etc.).

Number of doses

Twenty-five patients (83%) had received 2 doses of vaccine (15 with AstraZeneca and 10 with Sinopharm), while the remaining 5 patients (17%) had received a single dose (4 with AstraZeneca

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