3.1. Awareness and vaccination rates

Generally, awareness of HBV as an occupational risk and existence of the HBV vaccine was relatively high among health workers, with HBV awareness ranging between 52.0% [20] and 98.3% [24] and vaccine awareness ranging between 70.2% [21] and 98% [38]. However, vaccination rates were lower, with “ever vaccinated” rates ranging from 0% among medical-waste handlers in Ethiopia [45] to 91.9% in a study where a hospital in Nigeria introduced an HBV vaccination campaign for all staff [34]. Despite these wide ranges, the majority of studies found rates of 35–65% (Fig. 1). Completion of all three doses was much lower, ranging between 4.6% [7] and 64.4% [48], with post-vaccination immune testing ranging between 0% [20,46,48] and 12.7% [36] (Table 2).

Fig. 1

Boxplot of “ever vaccinated” vaccination status of Sub-Saharan health workers in studies that provided estimates of vaccination rates from 2000 to 2005 (n = 29).

3.2. HBV immunology

Seven studies assessed laboratory-based markers of HBV [7,27–29,42,43,48]. There was great variability in the immunological status of health workers, with the range of anti-HBC (indicating natural immunity from exposure to HBV infection) from 41% in Kenya [48] to 92% in Niger [43]. Acute infection and chronic carriage as determined by detection of HBV surface antigen ranged between 4% [48] and 25.7% [27] (Table 2).

3.3. Strategies and challenges

Only two studies reported on mandatory vaccination, including a subset of nurses in the Tshwane metro region [30] and some training institutions [35] in South Africa, but did not include comparisons of vaccination rates between mandatory versus voluntary participants. Vaccines were provided free of charge in most settings, but where health workers had to pay for vaccination, cost was often cited as a reason for non-uptake. Lack of awareness of vaccine availability in the institution/country, lack of time, and inadequate vaccine information were other commonly cited reasons. While HBV vaccination was generally acceptable in most of the studies, some health workers did not see its importance, and others feared the side effects of the vaccine.

Only two studies specifically targeted improved uptake of HBV vaccine, with one based in a hospital in Nigeria [34] and the other in a district in Kenya [48]. Both utilized an increased awareness/education of HBV, followed by achievement of vaccines being provided free on a voluntary basis, “ever vaccinated” rates of 91.9% and 81.8%, and completion rates of 50.3% and 64.4%, respectively. The Kenya study utilized pre-vaccination testing for anti-HBC to determine vaccination eligibility.

A key gap identified in several studies was the lack of comprehensive strategies for targeting health workers, resulting in inconsistent policies and implementation, lack of treatment options for infected health workers, and overall poor uptake of vaccine.

3.4. Malawi case study

There is no specific policy and no dedicated department overseeing issues of hepatitis in Malawi. The current 5-year strategic plan guiding prioritization of all activities in the health sector [52] does not mention hepatitis for health workers or the society overall. While HBV vaccination has been universally provided to infants in a combination vaccine (Pentavalent) since 2002 with coverage rates >95% annually [53], the immunization program does not provide HBV vaccine to health workers.

Of the nine policies and acts that address health-worker welfare, two mentioned the HBV vaccine and mainly mandating “employers” to provide the vaccine to newly recruited staff and to train health workers on risks (Table 3). While the government is the major employer of health workers in the country due to the decentralized system, this mandate falls on individual districts to decide when and how vaccination will be provided. The regulatory authorities have no explicit mandate to follow-up if this is done, and their major tracking is to ensure training institutions include training of nosocomial infections in their curricula.

The sampled training institutions did not have written policies on HBV vaccination for health workers, but do provide a mandatory HBV vaccine to students prior to clinical attachment. The government-run schools provided vaccination free of charge, while Mulanje Mission included payment for vaccine as part of the fees. None conducts pre- or post-testing for immune status (Table 4).

While the Infection prevention policy indicates the importance of HBV vaccination for healthcare personnel, it is unclear whether this extends to cleaners and other staff working in the hospital environment. As shown in the cases associated with the sample districts, the policy is interpreted differently at ground level (Table 4) and in some districts, does not extend beyond the district hospital setting to smaller facilities.

4.1. Vaccination of health workers in endemic settings

The primary challenge of whether it is necessary to provide the vaccine in highly endemic settings where potentially the majority of health workers may have already been exposed is a critical one that countries need to address. Studies from Niger and Cameroon found natural immunity rates (anti-HBC) >90% [28,43], and, therefore, few health workers needing vaccination. However, the diversity in HBV endemicity in the region, as seen in the wide range between 41% in Kenya [48] and 92% in Niger [43], means that ideally each country would be required to base their vaccination policy on its local levels of HBV endemicity among health workers.

According to WHO estimates for the general adult population, countries in the northern and western parts of the region (including Cameroon and Niger) are high endemicity countries, while the rest of the region is categorized as high intermediate [19]. In the USA and six European countries, health-worker vaccination is universally provided without prior testing due to their low HBV endemicity [58,59], except in special cases. This means that while universal vaccination of health workers (without prior immune testing) can be implemented in intermediate-endemicity countries in the region (since they will have higher proportions of susceptible health workers), targeted vaccination after immune testing may be an option for high-endemicity countries. Pre-vaccination screening may not only identify those needing to be vaccinated, but also chronically infected health workers that may benefit from antiviral treatment. While the studies above showed that it is possible to conduct pre-vaccination screening in a hospital/district setting, the logistical challenges and financial implications may limit its feasibility on a national scale. Additionally, with the increase in infant immunization in the region, there may be a need to continually review the strategies of addressing health-worker immunization as endemicity levels change [31].

4.2. Categorization of which health workers should receive vaccine

The next challenge is which health workers require vaccination. While a majority of studies focused on doctors and nurses, others showed that other cadres, including medical-waste handlers, mortuary workers, and support staff, were also susceptible to HBV in the region [23,36,40,45] and could potentially benefit from vaccination. As shown in the Malawi case study, without explicit guidelines on who should receive the vaccine, facilities focus on clinicians and nurses only, leaving other workers susceptible. Additionally, in the Malawi case, the cadres that districts/facilities targeted for on-the-job vaccination could have potentially already received vaccination during their training, even though one district highlighted that most staff had not previously received the vaccine. WHO does not recommend booster doses outside of cases where post-vaccination immune testing shows insufficient immune response [60]. Some settings stratify which health workers are vaccinated by type of work carried out in the hospital. However, the Centers for Disease Control guidelines make provisions that decisions regarding which additional health workers receive the vaccination can be guided by the facility [58], so potentially all workers in a hospital (including administrative staff) can receive the vaccine as was reported by some study sites [34]. Additionally, because students are often at higher risk for injuries (due to their inexperience), prioritizing vaccination while undergoing training is a key strategy that can optimize protection of health workers.

4.3. Competing priorities

While hepatitis is receiving more attention on a global scale, countries often have competing priorities in the health sector, as shown in a Malawi case where there was little-to-no mention of HBV in the key documents guiding the sector. Diseases, such as HIV, malaria, and tuberculosis, often have a more prominent focus in the region, meaning that resources for HBV prevention may be limited. While Gavi (the Vaccine Alliance) has assisted several countries in the region to introduce HBV vaccination (in a combined form, as Pentavalent) for infants at a subsidized cost [2], there is no provision for vaccination of health workers. Countries would have to bear this cost, which could be restrictive, especially if coverage of this cost is then required of the health worker.

4.4. Implementation challenges

Apart from cost, other challenges identified, such as lack of awareness of vaccine availability, poor vaccination-completion rates, and lack of explicit treatment options for exposed health workers, are also pertinent issues that any country in the region developing a policy for HBV vaccination of health workers needs to address. As shown in the two studies aimed at raising vaccine uptake [34,48], voluntary uptake rates can be relatively adequate where deliberate measures are implemented to make the vaccine available and increase vaccine awareness/knowledge among health workers.

There is often debate as to whether vaccination of health workers should be mandatory or voluntary, but both are possible in various settings [59] and as shown in the Malawi case study, where both strategies were used at different levels. None of the studies in our sample compared the strategies in terms of cost, uptake, or other factors. The voluntary or “opt in” strategy, where the institution has the vaccine, but it is up to the health worker to request vaccination, can raise uptake, but may have varying results at different healthcare levels [48]. Introduction of policies that mandate or encourage HBV vaccination in the workplace can result in a higher vaccination coverage [60]. Mandatory or “opt out” strategies, where the vaccine is offered to all eligible health workers and those who do not want to be vaccinated can choose not to receive it, were successful at increasing flu-vaccine coverage among health workers in a study in the USA [61]. Choosing which option to implement will be guided by the overarching laws and principles that guide freedom of choice/public health in each country.

WHO encourages innovative approaches to HBV vaccination, and our findings reiterate that a “one size fits all” policy cannot work across the region. Therefore, countries will need to develop unique and often targeted strategies to suit their specific country context.

4.5. Recommendations

While awareness of HBV and vaccination may be high, it is not sufficient to force increased vaccine uptake, therefore, more comprehensive measures addressing other barriers, such as cost and availability, to ensure uptake and compliance may need to be incorporated.

Where feasible, providing HBV vaccination as part of the default package of provisions for health workers via mandatory/“opt out” strategies may be effective in the region.

4.6. Study limitations

While our study provided an overview of findings related to health-worker HBV vaccination in the region, it had a number of limitations. There have been many changes in policies and modalities regarding HBV vaccination, especially following the WHO 2010 resolution [62]. Due to the 150-year span utilized in our study, older studies may not be reflective of current trends in the countries. However, only 12 of the 33 studies included were published prior to 2010; therefore, the majority of the studies were more recent and likely to reflect the current status of the countries. There was also variability within the studies on how some factors were categorized (e.g., vaccination status, knowledge, etc.). During data extraction and cleaning, we standardized terminology to categories that were more consistent across the studies. Finally, due to our small sample for the Malawi case study, findings from the training institutions and districts may not be reflective of all the facilities, and would likely benefit from a larger study to fully explore practices across the country.

Despite these limitations, our study provided a succinct summary on issues related to health-worker vaccination for HBV and context for further discussion and research on the topic in the region, including exploring cost implications for mandatory versus voluntary policies and how these affect uptake.

4.7. Conclusion

Countries in the Sub-Saharan region who want to implement HBV vaccination of health workers will need to base their strategies on local epidemiology and guiding principles. Such plans ideally should be guided by locally relevant evidence and experts and should be comprehensive (not just vaccination, but treatment and addressing of factors limiting uptake) and consistently applied throughout each country.