Streptococcus pneumoniae vaccination in older adults

[Vaccination in advanced age]

Infectious diseases are responsible for up to 5% of fatalities even in developed countries. In addition, there is an increasing susceptibility for infections in elderly people due to physiological aging of the immune system. The principles of vaccination are based on a targeted activation of the human immune system. Principally, a distinction is made between passive immunization, i.e. the application of specific antibodies against a pathogen and active immunization. In active immunization, i.e. vaccination, weakened (attenuated) or dead pathogens or components of pathogens (antigens) are administered. After a latency period that depends on the vaccine, complete immune protection is achieved and immunity is maintained for a certain period of time. In contrast to dead vaccines, by the use of live vaccines there is always a risk for infection with the administered vaccine. In passive immunization antibodies are administered. As a rule passive immunization is carried out in persons who have had contact with an infected person and in whom no or uncertain immunity against the corresponding disease is present. Based on the recommendations of the Standing Committee on Vaccination (STIKO), influenza, pneumococcal, herpes zoster, early summer meningoencephalitis (FSME) and travel vaccines are described.

[Pneumococcal vaccination for prevention of pneumonia]

Aging of the immune system, so-called immunosenescence, is well documented as the cause of increased infection rates and severe, often complicated courses of infections in older adults. This is particularly true for pneumococcal pneumonia in older adults; therefore, the standing committee on vaccination of the Robert Koch Institute (STIKO) recommends a once only vaccination with 23-valent pneumococcal polysaccharide vaccine for all persons aged 60 years and over. Furthermore, the 13-valent pneumococcal conjugate vaccine is also available for administration in adults and is recommended by the STIKO for particular indications. The advantage of the pneumococcal conjugate vaccine is the additional induction of a T-cell dependent immune response that leads to good immunogenicity despite immunosenescence. Initial data from a recent randomized controlled trial, so far only presented at conferences, confirm that the conjugate vaccine also provides protection against non-bacteremic pneumococcal pneumonia, which is not provided by the polysaccharide vaccine. Thus, there are two vaccines for prevention of pneumococcal diseases: one with a broader range of serotype coverage but with an uncertain protection against non-bacteremic pneumococcal pneumonia and another one with less serotype coverage but more effective protection. Vaccination of children with the conjugate vaccine also leads to a rapid decrease of infections by the 13 vaccine serotypes even in adults because of herd protection effects. For prevention of pneumonia in older adults the additional benefit of a concurrent application of influenza vaccine and pneumococcal vaccine should be considered.

Health maintenance in older adults: combining evidence and individual preferences

There is increasing interest in maintaining health and delaying disability for older adults as this population segment expands. And instead of focusing on a traditional disease-specific approach to health maintenance, there is an ongoing shift to a patient-centered approach, and defining outcomes based on the older adults' goals. In this approach, their goals and preferences are central, and other factors such as their health status and prognosis help determine which goals may be realistic. These subjective goals and objective characteristics are then balanced with the risks, benefits, and harms of established evidence-driven health-maintenance recommendations. Hence, older adults share their goals and preferences with clinicians; while clinicians share information on risks, benefits, harms, and uncertainties of existing health-maintenance recommendations, and help guide the older adult through how existing evidence can respond to their health goals and preferences. In this article, the concept of patient-centered care in the context of health maintenance for older adults is discussed; and health maintenance recommendations for older adults are reviewed.

Serotype distribution of invasive Streptococcus pneumoniae in Canada during the introduction of the 13-valent pneumococcal conjugate vaccine, 2010

A baseline serotype distribution was established by age and region for 2058 invasive Streptococcus pneumoniae isolates collected during the implementation period of the 13-valent pneumococcal conjugate vaccine (PCV13) program in many parts of Canada in 2010. Serotypes 19A, 7F, and 3 were the most prevalent in all age groups, accounting for 57% in <2 year olds, 62% in 2–4 year olds, 45% in 5–14 year olds, 44% in 15–49 year olds, 41% in 50–64 year olds, and 36% in ≥65 year olds. Serotype 19A was most predominant in Western and Central Canada representing 15% and 22%, respectively, of the isolates from those regions, whereas 7F was most common in Eastern Canada with 20% of the isolates. Other prevalent serotypes include 15A, 23B, 12F, 22F, and 6C. PCV13 serotypes represented 65% of the pneumococci isolated from <2 year olds, 71% of 2–4 year olds, 61% of 5–14 year olds, 60% of 15–49 year olds, 53% of 50–64 year olds, and 49% of the ≥65 year olds. Continued monitoring of invasive pneumococcal serotypes in Canada is important to identify epidemiological trends and assess the impact of the newly introduced PCV13 vaccine on public health.

Recommended routine vaccinations for older adults

A goal of primary prevention is to avoid the development of disease. Immunizations are one of several strategies used by clinicians in primary prevention. Influenza and pneumococcal disease--both preventable--cause significant morbidity and mortality in older adults who have an altered immune system, often have several chronic health problems, and are at higher risk for complications. Tetanus, while not as common in older adults, carries a high mortality rate in those 65 and older. These infections are associated with significant disability that results from hospitalizations for congestive heart failure, hip fracture, stroke, and pneumonia. The goal of immunizing older adults is to decrease functional decline and disability, as well as potential hospital admissions linked to these preventable diseases, which often exacerbate underlying health problems. Age-defined recommendations are available to guide clinicians on the appropriate vaccinations and schedules for administration to older adults.