The role of vaccination in prisoners’ health

Keywords::

• hepatitis
• prison health
• vaccination
• vaccine

After the introduction of clean drinking water, vaccination is probably the public health intervention that avoids the most premature deaths [1]. Vaccination, in general terms, is highly efficacious and cost effective and can eliminate and even eradicate some communicable diseases. In general, vaccines are administered according to age criteria (systematic vaccination schedules) or to individual criteria in risk groups (e.g., people with some chronic diseases). These strategies have gradually achieved higher vaccination coverages and in many vaccine-preventable diseases, herd immunity, which can reduce or even halt the transmission of certain diseases. Specific vaccination strategies include the search for and immunization of identified closed communities or difficult-to-treat population groups that may harbor pockets of susceptible subjects. In these cases, targeted interventions can improve coverages considerably with respect to the immunization policies of traditional healthcare services. The prison environment, with a defined population confined within a limited space, provides a paradigm for this type of intervention.

In addition to being an accessible population, the benefits of vaccination programs for prisoners are immense, as the risk of acquiring both vaccine-preventable and non-vaccine-preventable diseases is extremely high among prisoners compared with the general population. The determinants that increase the risk of these diseases include the large number of incarcerated persons, prison overcrowding, rotational dynamics in the prison population, the social heterogeneity of prisoners and the high prevalence of transmissible diseases in prisoners belonging to lifestyle risk groups, among others.

Although there are some guidelines and recommendations, both local ones and those of various international agencies, on the health aspects of prisons, the sections on the prevention of communicable diseases and vaccination are generally limited and do not adequately reflect their importance. Furthermore, most recommendations and approaches are not easily applicable to the reality of prison life [2]. There are few reports on this subject and operational research into vaccination programs and factors related to vaccination coverage in prisons is limited [3]. One potential explanation for this may be related to the fact that prisons were designed and structured essentially to ensure public safety. This ‘limited’ concept, which persists today, may work against the idea that a prison can be a place that provides a real opportunity and space for inmates to access healthcare and an important point in the overall, integrated strategy of reducing the incidence rates of vaccine-preventable diseases, both within and outside prisons. Access of prisoners to vaccination has a direct impact not only on the target population but also in the community, by preventing possible infections and the complications of transmittable diseases.

From the vaccinology point of view, prison inmates should be considered a health priority for the following reasons:

High risk of acquiring vaccine-preventable diseases

The prison population is mainly composed of young men from the lower social classes with low educational levels, family problems, poor work records and low use of health services. More than a third of prisoners remain sexually active in prison, mostly without protection [4]. In surveys in Welsh prisons, the proportion of men having sex with men was 14%, of whom 20% only carried out this type of activity while in prison [5]. More than half the prison inmates in the UK have a tattoo and 11% were tattooed during their imprisonment, generally using homemade, shared implements [6]. The prevalence of illicit drug use in prisons, according to self-reports, ranges between 22 and 48% around the world. Injecting drug use is between 6 and 26%, of whom 25% began injecting while in prison [7–10].

The aforementioned risk factors entail a much higher prevalence of viral hepatitis among prisoners than in the general population. For example, the mean seroprevalence of hepatitis B is four- to five-times higher in prisoners than in the reference general population. In the USA, 40% of chronic viral hepatitis carriers were once imprisoned [2].

With respect to the prevention of the complications of chronic infectious diseases in prisons, one study found that the seroprevalence of HCV infection in Western European prisoners is approximately 25% [11], a figure that reaches 40% in some US states [12]. In addition, some studies suggest that 25% of HIV-infected individuals are former prisoners and that in most prisons the rates of HIV and TB infection are systematically higher than those of the general population. In all of these cases, routine influenza, viral hepatitis or conjugate pneumococcal vaccination could prevent serious complications among carriers of these diseases.

Prison population in close contact with the general population

Although considered as closed institutions, prisoners have visitation rights, leave periods and other privileges that allow them to mix with the nonprison population, as well as the fact that many prisoners are serving only short sentences. The annual flow of prisoners may be as much as five-times the total permanent prison population, an indirect indicator of the interaction between the prison population and the rest of society [13].

Easily accessible population susceptible to vaccination

Access to prisoners is simple. This should ensure that high vaccination coverages are easy to reach and satisfactory results easy to obtain [14,15].

The three reasons referred to above explain the importance of vaccination programs in prisons. However, the precarious structural and logistical conditions of prisons in some countries, which are associated with overpopulation, overcrowding, poor ventilation of cells, poor sanitation and hygiene, poor food quality and so on, are additional risk factors that should be considered per se as additional risk factors for the transmission of vaccine-preventable diseases.

Likewise, prisons often contain a substantial proportion of prisoners with chronic diseases (whether infectious or not) and of people aged 65 years or more. In these groups, specific vaccination programs are necessary, just as in the general population.

In prisons, vaccines are administered for various purposes or objectives. The most common is systematic vaccination, either as primary vaccination, as a booster dose or as postexposure treatment (e.g., booster doses of tetanus and diphtheria vaccine in adults or primary hepatitis B vaccination). In recent years, the prison population has undergone demographic changes that mirror those of the general population, such as the increase in the number of immigrants in prisons in Europe and the USA. This has resulted in the need to access and vaccinate a population coming from countries where vaccination coverage is poor or where there is little data, making catch-up or rescue vaccination strategies necessary to prevent outbreaks within prisons, as has been described for measles, mumps or chickenpox in several countries with high immigrant populations [16–18].

In addition to ensuring the completion of the recommended adult immunization schedule in prisoners, vaccinations that may be associated with the intrinsic epidemiological risk of each individual prison must be identified and then administered. This helps improve disease prevention, not only among prisoners but also among prison workers and, secondarily, their families and the wider community. Vaccination programs in prisons are therefore essential to achieve population-based health objectives, without ignoring other, more basic interventions that help to reduce the spread of infections and improve the quality of life in prisons, such as the quality of prison sanitation, drainage, ventilation or food, combined with programs to facilitate easy access to syringes or condoms, for example.

In the UK, one of the indicators of quality care in prisons is that 80% of all prisoners be immunized against hepatitis B in the first 30 days after incarceration [101]. It is debatable whether offering immunization immediately after incarceration is the most appropriate strategy, when the mood and psychological state of a newly incarcerated prisoner is considered. This strategy could be a barrier to adherence to the recommended vaccination schedule and result in noncompletion. Prisoners may be less likely to reject vaccination if this is offered actively and continuously some time after incarceration, when the inmate’s attitude may be more responsive and the environment may seem less alien. Therefore, ideally, the vaccination of prisoners should be seen as something that is not applied automatically, but rather is linked to ethical concerns and respect for the individual [19].

Given all this, the dynamic and constantly changing group of people who reside and work in prisons should be taken into account in the immunization programs of countries, regions and cities. Although immunization in prison may be designed as a strategy of preventive interventions focused on high-risk groups, this opportunity, which may be the only way that these persons can easily access the health system, should be based on a policy of permanent access to vaccination that is actively pursued. Completion of the recommended adult vaccination schedule should be the first priority, followed by vaccinations associated with the intrinsic risk posed by prison life and each individual prison. Such a policy makes it easier to prevent disease transmission in prisoners, prison staff, families and the wider community, and provides benefits for the health system in general [20] and is also cost-effective [21]. Therefore, it is essential to seek systematic, consensual guidelines for specific programs of vaccination and their management in prisons. These should not merely be independently applied actions but rather measures integrated and spelt-out in national or regional public health plans for the control of vaccine-preventable diseases.

Financial & competing interests disclosures

JM Bayas has been principal investigator in vaccine clinical trials sponsored by GlaxoSmithKline and Sanofi Pasteur MSD. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.