Assessment of vaccine candidates for persons aged 50 and older: a review

Abstract

Background: The increasing life expectancy in most European countries has resulted in growth of the population 50 and older. This population is more susceptible to infectious diseases because of immunosenescence, co-morbidity and general frailty. Thus, to promote healthy aging, vaccination against vaccine-preventable-diseases could be one strategy. In addition to its possible individual benefits, vaccination may also yield social benefits, such as a lower overall cost of healthcare. Most European countries, however, offer only influenza vaccine although vaccines for pneumococcal disease, herpes zoster, pertussis, and hepatitis A are also available. Our aim is to review the knowledge of these vaccines for persons aged 50 and older and explore the arguments for expanding current vaccination programmes beyond just influenza.

Methods: The evaluation model of Kimman et al. was used to assess herpes zoster, pneumococcal disease, pertussis and hepatitis A in terms of four domains: pathogen, vaccine, disease outcomes and cost-effectiveness. The sources were Dutch surveillance systems, seroprevalence studies and the international literature.

Results: Herpes zoster, pneumococcal disease and pertussis are prevalent among persons aged 50 and older. Vaccines vary in effectiveness and have mild and self-limiting side effects. Vaccination against pneumococcal disease and pertussis causes adaptation of the responsible pathogen. For pertussis and hepatitis A, the vaccine is not registered specifically for the elderly population. Vaccination against herpes zoster and pertussis could improve quality of life, while vaccination against pneumococcal disease and hepatitis A prevents mortality. However, only vaccination against herpes zoster and pneumococcal disease appear to be cost-effective.

Conclusions: Vaccination can improve the health of the elderly population. As our review shows, however, the data are too incomplete to accurately judge its potential impact. More research is needed to determine how vaccination can most effectively improve the health of the growing population 50 years and older.

Figure 1

Considerations in adapting the national immunization programme [9].

Figure 2

Notifications for pertussis from 2000 to 2011 for persons aged 50 years and older. The dots on the black line represent the number of notifications of pertussis per 100.000 persons 50 years and older for 2001 to 2012.

Figure 3

The effectiveness of Zostavax for preventing HZ, burden of illness and PHN among different age groups [38]. The light grey bar represents the vaccine effectiveness on the incidence of herpes zoster, the burden of illness and postherpetic neuralgia of the total study population. The white bar represents the vaccine effectiveness on the incidence of herpes zoster, the burden of illness and postherpetic neuralgia for those aged 60–69 years. The dark grey bar represents the vaccine effectiveness on the incidence of herpes zoster, the burden of illness and postherpetic neuralgia for those 70 years and older.