During December 2019, in Wuhan City, China, the novel coronavirus disease 2019 (COVID-19) was caused by the severe acute respiratory syndrome coronavirus 2 (Harapan et al. 2020). On 30 January 2020, the World Health Organization (WHO) declared COVID-19 a Public Health Emergency of International Concern (Harapan et al. 2020). Within the subsequent 2 weeks, 49 053 laboratory-confirmed cases and 1381 deaths were reported globally (Harapan et al. 2020). World Health Organization officially declared COVID-19 a global pandemic on 11 March 2020 (WHO 2023). During the first 6 months, the pandemic caused over 1 million deaths worldwide (Hodgson et al. 2021), prompting the accelerated development of COVID-19 vaccines (vaccine/s) (George et al. 2023c) to reduce hospitalisation, disease severity and mortality rates.

By April 2021, South Africa (SA) reported over 1.5 million confirmed COVID-19 infections and about 53 356 fatalities, with KwaZulu-Natal (KZN) contributing 335 177 cases and 10 271 deaths (National Institute for Communicable Diseases [NICD] 2021). To avert more deaths, SA commenced the vaccine rollout with the Sisonke study by vaccinating healthcare workers (HCWs) and expanding vaccines to the general population by the end of 2021 (National Department of Health [NDOH] 2021b). By December 2023, 67% (n = 13.6 billion) of the global population received a complete primary series of vaccines, with Africa reporting 33% (n = 646.5 million) and SA at 35% (n = 41.8 million) (WHO 2024). These low coverage rates among the general population, particularly in Africa and SA, reinforce that vaccine hesitancy constituted a major barrier to the success of vaccination programmes (Ackah et al. 2022). This challenge was further underscored by the considerable variation in HCW vaccine acceptance rates observed globally and in SA, irrespective of their levels of vaccination knowledge (George et al. 2023c; Kigongo et al. 2023; Oberleitner et al. 2022; Verger et al. 2021). Therefore, this reinforced that vaccine hesitancy represents a complex and multifaceted global challenge that transcends national boundaries, socioeconomic statuses and stages of development (Baspakova & Sartayeva 2023).

Healthcare workers such as doctors, nurses and pharmacists, in particular, played a key role during the COVID-19 pandemic, and their knowledge, attitudes and responses to the vaccine and COVID-19 vaccine booster doses (booster doses) offered important insights into general vaccine acceptance and hesitancy (Wang et al. 2022).

Communities and patients depended on HCWs for reliable vaccine information, and HCWs’ views strongly influenced the vaccination choices of patients, families and communities (George et al. 2023c). Unvaccinated HCWs faced a higher risk of COVID-19 infection and hospitalisation (Dror et al. 2020), leading to staff shortages, increased workloads and a reduced ability of the health system to manage the pandemic effectively.

In Israel, the vaccine acceptance rate was reported at 68% and 61% among doctors and nurses, respectively (Dror et al. 2020), whereas the United States reported a higher vaccine acceptance rate of 85.7% (Oberleitner et al. 2022). In France, a complex picture was revealed, with 48.6% of HCWs highly accepting, 23% moderately accepting and 28.4% hesitant (Verger et al. 2021). In sub-Saharan Africa, a systematic review of about 7500 HCWs yielded a vaccine hesitancy rate of 46% (Kigongo et al. 2023). A scoping review conducted by Ackah et al. (2022) in Africa identified that vaccine acceptance rates varied between 6.9% and 97.9% (Ackah et al. 2022).

In SA, the reported vaccine acceptance rates among HCWs varied notably across studies. Adeniyi et al. (2021) found a vaccine acceptance rate of 90.1% (n = 1308) in 2021, while a separate study by Wiysonge et al. (2022) reported a substantially lower rate of 50% (n = 395) during the same year (Adeniyi et al. 2021; Wiysonge et al. 2022). More recently, George et al. (2023c) documented a vaccine acceptance rate of 89% (n = 7763) among HCWs in 2022 (George et al. 2023c). Another SA study (n = 89) indicated that only two-thirds of HCWs were supportive of mandatory workplace vaccinations (Naidoo & Taderera 2025). Kigongo et al. (2023) concluded that there was a need to better understand obstacles HCWs faced in vaccinating, as they had the potential to influence the broader public (Kigongo et al. 2023).

Research on the vaccine and booster acceptance rates predominantly concentrated on HCW in high-income countries, with limited data available from the African continent, including SA (George et al. 2023b), and KZN province. While the above studies offer valuable insights into vaccine hesitancy and acceptance, none of these studies specifically compare public sector (PUBS) and private sector (PRIVS) vaccine and booster dose acceptance rates and associated acceptance and refusal reasons. Public sector and PRIVS serve different populations and operate under distinct resource constraints (Wilkinson et al. 2022), which can shape attitudes, access, and behaviours related to vaccination. Therefore, there was a need to identify sector-specific barriers and facilitators and develop targeted interventions to address unique challenges, ultimately improving overall vaccine coverage and public health outcomes.

Furthermore, a lack of studies was noted examining the influence of knowledge, education and workplace training on vaccine and booster acceptance and refusal in PUBS and PRIVS in KZN, SA. Healthcare workers play a central role in vaccine advocacy and public trust (George et al. 2023b), and their acceptance or hesitancy directly impacts community perceptions and vaccination rates.

Therefore, our study aimed to determine the level of vaccine and booster acceptance among PUBS, PRIVS and public-private (PUBPR) HCWs in KZN, SA, and to identify the key drivers of vaccine and booster acceptance and refusal.

The objective of this study was to compare vaccine and booster acceptance rates among PUBS, PRIVS and PUBPR HCWs in KZN, SA and the primary reasons influencing vaccine and booster acceptance and refusal among these sectors.

The primary outcome of this study was the acceptance of vaccine and booster doses. In addition to this primary outcome, this study also investigated secondary outcomes, including participants’ demographic characteristics (such as age and gender), educational backgrounds, professional roles and perceptions or attitudes towards the acceptance or refusal of the vaccine and booster doses.

The reliability and validity of the online questionnaire were ensured by designing standardised and clear questions, drawing from validated instruments. The questionnaire was reviewed by public health experts. Pilot testing and refined wording ensured comprehensive coverage of relevant constructs. Anonymity and confidentiality were assured to promote honest responses, and technical functionality was tested across multiple devices. Measures were implemented to prevent duplicate responses and minimise sampling bias, supporting the robustness and credibility of the study findings.

The average vaccine acceptance rate of 92.4% (n = 306/331) among HCWs in KZN was notably high, exceeding 90.1% (n = 1308) and 89% reported in previous SA studies (Adeniyi et al. 2021; George et al. 2023c). Our study identified that vaccine acceptance across different sectors was associated with demographic factors, educational background, training opportunities and the use of chronic medications.

Conversely, vaccine refusal was associated with perceptions regarding vaccine safety and efficacy, levels of institutional trust, religious beliefs, beliefs in natural immunity and exposure to misinformation.

Approximately half of the participants received the J&J vaccine, mirroring the preferences documented in the Sisonke study and the initial national rollout (NDOH 2021a).

This study’s average booster acceptance rate of 73.7% (n = 244) closely aligns with a study from India (Rathinakumar et al. 2024) and is considerably higher than the 56% reported in a recent South African study (George et al. 2023a). This disparity may be because of differences in study populations, timing, regional infection rates and public health messaging (George et al. 2023a). Lower booster rates in this study may be attributed to concerns about safety, potential side effects, beliefs in natural immunity and apprehension regarding the necessity for repeated doses, consistent with findings from previous research (George et al. 2023a).

This study found that age, gender and race emerged as significant factors affecting booster uptake. Our findings indicate that the lower uptake of boosters in individuals aged 50–59 may have been potentially influenced by concerns about side effects and the frequency of additional doses (George et al. 2023a). This outcome diverges from previous global research, which has generally reported higher vaccine acceptance rates among older adults (Biswas et al. 2021).

Despite higher initial vaccine acceptance by PUBS and PRIVS, females were less likely to receive boosters, corroborating findings from another South African study (George et al. 2023a). A global study found that this disparity may be rooted in gender-specific health beliefs and safety concerns (Skjefte et al. 2021).

Racial and sectoral differences were also apparent in booster acceptance between African and white counterparts. This finding suggests that cultural, linguistic or historical trust issues remain barriers to vaccine acceptance (Adhikari, Yeong Cheah & Von Seidlein 2022), emphasising the necessity of tailored, community-specific strategies and communication.

Public-private doctors recorded the highest vaccine uptake, followed by PUBS pharmacists. Possible explanations include pharmacists managing vaccine supply chains and information dissemination (NDOH 2021a). Meanwhile, doctors in both PUBS and PRIVS also noted a slightly higher booster uptake compared with the vaccine. This was consistent with their exposure to emerging COVID-19 variants and evolving SA and global scientific guidance (Biswas et al. 2021; George et al. 2023a). These findings aligned with prior research indicating that vaccine attitudes and behaviours among HCWs are influenced by their workplace context and professional roles (Biswas et al. 2021). Meanwhile, another SA study found that vaccine acceptance was seen to be considerably higher in HCWs with tertiary education, while lower-educated categories of HCWs could have benefited from targeted vaccine education efforts (Adeniyi et al. 2021).

Our study found that the pivotal role of undergraduate education and organisational training in vaccine uptake was evident. The rate of adequate undergraduate vaccine training differed among the sectors, with the highest recorded in PUBPR. This highlighted the need for standardised undergraduate vaccine education programmes. Such standardised curricula would provide essential foundational knowledge and create opportunities to address students’ concerns, reduce vaccine hesitancy and enhance awareness regarding vaccinations (Belingheri et al. 2021). This study identified that limited advanced understanding of vaccines across diverse sectors was a cause for concern, as this may have substantially undermined vaccine confidence, reduced uptake and hindered efforts to effectively combat vaccine-related misinformation (Parisi et al. 2025). Peterson, Lee and Nugent (2022) also noted that the majority of HCWs lack specialised training in immunology and vaccinology; thus, their experience in administering vaccines does not inherently confer an in-depth understanding of vaccine development (Peterson et al. 2022). Limited exposure to the clinical trials and public health initiatives may undermine their confidence in, and perceptions of, vaccine safety and efficacy, potentially contributing to vaccine hesitancy (Peterson et al. 2022). Nevertheless, hesitancy persisted even among some with advanced knowledge, illustrating the complex nature of vaccine acceptance and decision-making (Peterson et al. 2022).

Our study highlighted that PUBS and PRIVS HCWs who refused the vaccine did not promote vaccination to family and friends. This effect was especially marked among PRIVS participants, aligning with the local and international studies that reported that vaccine refusal was consistently linked to a lack of vaccine advocacy (George et al. 2023c; Roberts et al. 2022). This pattern highlighted the extent to which a HCW’s personal vaccination decisions significantly impact their effectiveness as vaccine advocates, potentially influencing overall community vaccine uptake and the spread of positive vaccine information (Belingheri et al. 2021).

Our study concurred with the conclusions of Roberts et al. (2022) identifying the need to change attitudes (Roberts et al. 2022). This can be done by unifying messages, normalising conversations and providing proper training and resources (George et al. 2023c).

Public sector facilities appeared to have more structured or mandatory vaccination training, provided by the NDOH (2021a). While this reflects greater institutional emphasis on staff preparedness and education, our study highlighted that this may not have translated into a higher PUBS vaccine acceptance rate. A blended approach (online and face-to-face) indicates a recognition of diverse learning preferences and the need to use suitable and sustainable training methods for quick, ongoing and tailored training. Our study data indicate a potential association between insufficient training and refusal of vaccines or boosters, suggesting that training may be a factor in promoting vaccine uptake, consistent with another SA study (Wiysonge et al. 2022). Conversely, research conducted in Sierra Leone reported that while HCWs experienced a lack of education, this did not correspond to an unwillingness to receive vaccination (Joseph et al. 2023). As a result of almost one-third of PUBS and PRIVS not being able to ask questions during training, our study reinforces the importance of interactive training sessions, as well as opportunities for questions and critical discussion.

This study noted a higher rate of PRIVS positive COVID-19 tests in comparison to PUBS, which may indicate higher exposure risk in private healthcare settings, and more COVID-19 testing among PRIVS participants. Commonly reported mild or moderate illness in this study aligns with existing evidence that vaccination reduces the severity of COVID-19 outcomes, even when breakthrough infections occur (Huang & Kuan 2022).

Vaccine refusal reasons showed notable differences among PUBS, PRIVS and PUBPR. Both PUBS and PRIVS expressed concerns about vaccine safety, with high proportions agreeing that negative experiences of friends and/or family, a lack of trust in vaccine efficacy and suspicions about manufacturers’ profit motives contributed to their reluctance. These findings echoed in other SA and global studies (Dror et al. 2020; George et al. 2023a). Vaccine accessibility was not identified as a refusal reason in this study, consistent with the findings of another SA study (Naidoo & Taderera 2025). Close to 10% of PUBS and PRIVS participants agreed with the use of traditional medicines for COVID-19 treatment, with a slightly higher rate seen in PRIVS. This perspective diverges from findings from another South African study, which reported that a significant proportion of university staff and students utilised traditional medicines during the nationwide lockdown (Mphekgwana, Makgahela & Mothiba 2021). However, WHO emphasises the importance of an evidence-based approach to traditional medicine, advocating for the establishment of efficacy and safety through rigorous scientific validation (WHO 2025). Additionally, a total of 30% of PUBS and PRIVS in our study cited natural immunity as a reason for vaccine refusal, with a higher rate in PUBS. This is similar to findings of SA and global studies, which underscores natural immunity and a low perceived severity of COVID-19 among these groups (George et al. 2023c; Wong et al. 2023). This study raised concerns about microchips in vaccines (Wong et al. 2023), which were dismissed by the majority of participants in our study. Approximately one-third of study participants expressed distrust in the government, aligning with the primary reasons identified by George et al. 2023c. Religious reasons were cited by about a quarter of PUBS and PRIVS refusing the vaccine, and higher in PRIVS. Similarly, a Malaysian study highlighted the significance of the ingredients and halal status of vaccines on the uptake of vaccines (Wong et al. 2023). This highlights a disparity between religious and traditional leadership and public health programmes. The influence of anti-vaxxers, particularly via social media, remains a significant threat to public health initiatives (Hoare, Mendelson & Frenkel 2022). Effective communication strategies must address misinformation directly and be tailored to the unique challenges of online platforms and resistant groups. The majority of PUBS and PRIVS participants acknowledged encountering negative effects on social media. Social media was consistently identified as a prominent source of adverse information, mirroring global patterns in the dissemination of vaccine misinformation (Skafle et al. 2022). The rapid development of COVID-19 vaccines and uncertainties regarding long-term side effects were particularly influential among PUBS and PRIVS, consistent with research suggesting that perceived scientific uncertainty can undermine vaccine confidence (Dror et al. 2020; George et al. 2023c).

The study found that half of the PUBS and PRIVS participants refusing booster were uncertain about booster safety, mirroring findings both nationally and internationally (Dror et al. 2020; George et al. 2023b). Public sector participants predominantly rejected the belief that booster doses compromise the immune system, reflecting a moderate level of vaccine literacy within this group, potentially linked to their higher rates of training. This is consistent with the findings of Fenta et al. (2023), who concluded that improving health literacy through varied vaccine promotion strategies can increase COVID-19 vaccine acceptance and support informed decision-making, ultimately reducing the impact of the pandemic (Fenta et al. 2023). Almost half of PUBS participants agreed that acquiring natural immunity and antibodies after COVID-19 infection paralleled evidence that perceived natural immunity often diminishes the need for booster uptake (George et al. 2023b; Wong et al. 2023).

While most of the vaccine side effects were mild or moderate, a substantial proportion of the study participants did not report side effects, indicating a need for improved pharmacovigilance education and awareness (South African Health Products Regulatory Authority [SAHPRA] 2023). Concerns about vaccine effectiveness against emerging variants were prominent, with about one-third expressing doubts – consistent with literature highlighting the impact of viral mutations on vaccine efficacy (George et al. 2023a; Ghildiyal et al. 2024).

This study concludes that vaccine acceptance and confidence among HCWs are shaped by a complex interplay of workplace environment, demographic factors, training and exposure to information or misinformation.

Notably, PUBPR participants demonstrated the highest rates of vaccine and booster acceptance, suggesting that a dual work environment may provide more practices and educational resources that fostered greater vaccine confidence and uptake. Public sector participants exhibited strong training and showed greater resistance to misinformation. However, PUBS noted firmer belief in acquired immunity and the vaccine’s ineffectiveness against new COVID-19 strains. Moreover, PUBS recorded neutrality towards some conspiracy theories, along with the highest booster refusal rate, reinforcing ongoing uncertainties. In contrast, PRIVS participants reported more chronic medication use and COVID-19 cases, greater uncertainty about vaccine safety and efficacy, and were more influenced by social and religious factors, contributing to higher booster hesitancy.

Across PUBS, PRIVS and PUBPR, attitudes and beliefs were influenced by personal experiences, demographic background, training and social influences.

Addressing the complex determinants of vaccine hesitancy across healthcare sectors necessitates a structured, integrated, and sustainable policy-driven approach reinforced by multidisciplinary stakeholder engagement.

This should commence with the incorporation of vaccine education into undergraduate healthcare curricula, extend to continuous workplace training, and include targeted programmes for religious, community and traditional leaders. The implementation of such comprehensive, proactive strategies is critical for enhancing vaccine confidence, increasing uptake and safeguarding public health, thereby ensuring preparedness for future pandemics.