In 1997, Titmuss considered blood donation to be the most beautiful symbol of giving to strangers, in that it is a gift of life, a gift of oneself [1]. Blood donation is therefore a voluntary, anonymous, and altruistic act that consists of authorizing the removal of a certain quantity of one’s blood (whole blood donation) or certain of its components (plasma and platelet donation) for use in blood transfusions to save lives or improve the quality of life of patients. These blood transfusions can transmit infectious agents. [2] and [3] are present in the donor’s blood, and therefore all blood donations must undergo rigorous testing. Among these infections, hepatitis B, given its numerous routes of transmission, is one of the most dangerous infections that can affect the quality of blood donations. Infection with the hepatitis B virus (HBV) is a major public health problem worldwide. Viral hepatitis B is an infectious, contagious disease caused by a hepatotropic virus and is extremely widespread. The hepatitis B virus (HBV) causes inflammation of the liver. The infection can be acute (severe and short-lived) or chronic (long-term). Lead to a significant risk of death from cirrhosis or liver cancer. HBV belongs to the Hepadnaviridae family. This family includes all viruses whose genome consists of circular double-stranded or partially double-stranded DNA and possesses reverse transcriptase. Ten HBV genotypes have been identified and are labeled A to J. In Cameroon, it has been reported that genotypes A and E circulate in a study population [4]. According to the World Health Organization (WHO), approximately 2 billion people worldwide carry serological markers for the hepatitis B virus. In 2015, the WHO estimated that 257 million people were living with chronic hepatitis B. It is particularly prevalent in sub-Saharan Africa and East Asia, affecting 5% to 10% of all adults, while in North America, less than 1% are infected. The estimated prevalence is less than 5% in Eastern Europe, 1.5% in Northern Europe, 2% in Southern Europe, and 1% in Western Europe. In Cameroon, its prevalence was estimated at 11.2% in a meta-analysis [5]. However, this is a preventable infection thanks to vaccination, which has been available since 1981 [6]. In a context where blood donations are steadily declining in blood banks, it seems appropriate to secure and retain blood donors through appropriate and complete vaccination to provide them with protective humoral immunity against the hepatitis B virus (HBV). An individual is considered immune when they have a sufficient level of antibodies directed against the surface antigen (anti-HBs antibodies). These antibodies can develop through vaccination or after exposure to the hepatitis B virus. However, certain factors such as age, weight, and lifestyle can influence an individual’s immunity. Hepatitis B virus infection remains a significant threat to our blood banks despite the preventive measures implemented over the past three decades. Similarly, despite the high prevalence of HBV in Cameroon, very few studies have been conducted on the immunity status of blood donors. Therefore, in a context where blood donations are scarce in our blood banks, ensuring immunity against the hepatitis B virus is of particular importance for the protection of donors. This study was thus conducted to evaluate the humoral immunity status against the hepatitis B virus in regular blood donors at the Yaoundé Central Hospital blood bank in Cameroon.

During the study period, 155 blood donors were initially enrolled at the HCY blood bank. Of these 155 donors, sixteen did not consent (10.32%). Blood was collected from 139 donors; among them, eleven (7.91%) were excluded from the study, including four (36.36%) who were HBsAg positive and 7 (63.63%) whose samples were hemolyzed.

In the end, 128 potential donors were selected. The male-to-female ratio was 4.12 (103 men and 25 women). The mean age of the participants was 31.44 ± 7.44 years, with a range from 20 to 63 years (Table 1).

Table 1. Distribution of blood donors by age group.

The objective of this study was to evaluate the status of humoral immunity against the hepatitis B virus in regular blood donors. More specifically, it aimed to assess the vaccination coverage of regular blood donors at the HCY blood bank, determine the rate of humoral immunity, and identify any factors that could influence the development of humoral immunity. Overall, regular blood donors were predominantly male (80.47%), with a male-to-female ratio of 4.12. The minority of female donors could be explained by certain physiological conditions specific to women, such as breastfeeding, menstruation, and pregnancy. Our population comprised two types of donors: voluntary donors (17) and family donors (111). The type of donation is an important characteristic due to its direct impact on transfusion safety [8]. It can be deduced that the population does not have a culture of voluntary blood donation, hence the high number of family donations. Patients requesting blood are at risk of contracting parenterally transmitted infections. In our study, we determined vaccination coverage among regular blood donors and found a vaccine exposure rate of 13.28% with a completion rate of 11.72%. This vaccination coverage remains low. Given that more than half the population was aware of the vaccine’s existence and that our study took place in an urban setting, we would have expected higher coverage. This could be explained by a lack of awareness about the importance of vaccination, as Cameroon does not yet have a national policy for vaccinating regular blood donors, but also by some people’s ignorance of the existence of a vaccine against HBV. Similar rates have been reported in Cameroon among medical students, such as 17.6% by Bagnaka et al. in 2011 and 18% by Noubiap et al. in 2012 [9][10]. Given that these surveys were also conducted in urban areas, this slight difference could be explained by the fact that medical students have a good knowledge of the hepatitis B vaccine due to their training. However, in 2018 in Cameroon, a study by Aroke et al. found a coverage rate of 26.05% among medical students, while another survey conducted in 2017 by Meriki et al. in Cameroon reported 30.2% [7][11].

Determining humoral immunity against the Hepatitis B virus in regular blood donors revealed that 33.59% of the population had an immunizing level against HBV. This prevalence could be explained by two factors: First, our study showed that among the 15 donors with complete vaccination, only 8 (53.33%) had an immunizing humoral response, representing half of the total. This low prevalence among vaccinated individuals could be explained by several factors, such as the fact that the absence of a protective Anti-HBs titer in vaccinated patients does not preclude the presence of memory immunity against HBV [12]. Age influences the vaccine response and this low response among donors exposed to the vaccine could be due to cases of non-responders. However, these frequencies are significantly higher than those observed in a study conducted by researchers Al Mutairi and colleagues in Saudi Arabia in 2011 (3.34%), and Japhet et al. in Nigeria, who reported 15.2% in 2011 [13][14]. These discrepancies could be attributed to hepatitis B vaccination coverage, which varies from one country to another. Donor lifestyles could also contribute to these differences.

Secondly, most of these subjects appear to have humoral immunity resulting from HBV exposure, since all our donors were HBsAg negative. This is confirmed by at least two facts: a vaccine exposure rate of 7.03%, a humoral response rate of 33.59% (which is higher than the exposure rate), and an overall HBV exposure prevalence of 59.4%.

These results demonstrate considerable exposure of the donors to HBV. However, the presence of anti-HBcAg alone, in the absence of HBV DNA testing, does not allow for a diagnosis of occult hepatitis B, and this reactivity cannot, by itself, be interpreted as evidence of occult HBV infection in these donors; the prevalence of occult HBV infection was therefore not assessed in the present study. A more recent study conducted between February and June 2025 at the same blood bank confirmed occult HBV infection in 9 of 269 donors (3.34%) through detection of HBV DNA, with co-circulation of genotypes A and E [15]. This high exposure to HBV could be explained by the fact that Cameroon is located in a high-endemicity zone, with a seroprevalence of 11.2%. A similar study conducted by Etheline et al. in Cameroon in 2017 reported an exposure prevalence of 47.3% [16]. Our exposure rates are higher than the 19% reported by Tatsilong et al. in 2016 in Cameroon [17]. This difference in prevalence could be due to the difference in the diagnostic technique used, as Tatsilong et al. worked with the rapid strip test, which has relatively lower sensitivity and specificity compared to the ELISA technique used in our study.

The identification of factors that could influence humoral immunity in blood donors revealed no significant differences for sociodemographic factors, including age and sex. Yihua Zhou et al., in their 2019 study conducted in China, also found no significant differences for these two factors [18]. However, in univariate analysis, we were able to establish that receiving at least three (3) doses of vaccine was significantly associated with the development of protective humoral immunity. Mwangui et al., in Kenya, also obtained a similar result [19]. This result is explained by the fact that the HBV vaccine provides immunity in at least 90% of cases, and that taking three (3) doses of the vaccine ensured complete immunization. Furthermore, taking a single dose of the vaccine does not provide immunity. This demonstrates in our study that vaccination was the sole factor in the development of humoral immunity.

This study shows that vaccination coverage among blood donors is low and that vaccination completeness is the factor that effectively influences the occurrence of protective humoral immunity. These data sufficiently prove that there is an urgent need to put in place vaccination strategies whose main purpose will be to demonstrate the importance of protecting oneself against HBV through vaccination.

One limitation of this study is the absence of objective verification of the number of vaccine doses received, as the data were collected based on participants’ self-reported recall in the absence of an available vaccination booklet at the time of data collection; these data are therefore subject to recall bias, which may lead to an underestimation or overestimation of the true vaccination coverage.

Transfusion-transmitted HBV is a reality in countries where blood donations are not tested for HBc antibodies and the viral genome.

The vaccination coverage against HBV is 13.28% in the HCY blood bank.The immunization rate against HBV is 33.59%, mainly resulting from possible exposure to the virus.

We extend our thanks to the participants, the staff of the HCY blood bank and the hospital management.

Conceptualizationofthestudy: Symphorien Ewodo, Guy Roger Nsenga;

Methodology: Symphorien Ewodo, Guy Roger Nsenga, Amira Sandra Ndam;

Validation: Symphorien Ewodo, Guy Roger Nsenga, Nadesh Ashukem Taku;

Analyses: Amira Sandra Ndam, Nadesh Ashukem Taku;

Investigation: Amira Sandra Ndam;

Originalarticle: Amira Sandra Ndam;

Articlecorrection: Symphorien Ewodo, Nadesh Ashukem Taku, Abdou Koudous Bebeto Chouwat, Donald Muwud Tebo, Elvige Geukeng Dongmo, Hortense Ngegni Pangetna;

Translation: Donald Muwud Tebo;

Supervisor: Symphorien Ewodo, Guy Roger Nsenga;

AdministrativeProject: Symphorien Ewodo, Amira Sandra Ndam, Guy Roger Nsenga, Simon Noel Ateba, Claude Tayou Tagni.

All participants signed a handwritten consent form to participate in our study.

The data supporting the conclusions of this study are available from the corresponding authors upon reasonable request.