Mazen S. Bader, MD, FRCPC, MPH, Department of Medicine, Division of Infectious Diseases, Memorial University of Newfoundland and Labrador, St. John’s, NL.
Daniel Hinthorn, MD, FACP, Department of Medicine, Division of Infectious Diseases, University of Kansas Medical Center, Kansas City, KS, USA.

Preventive health interventions are key to maintaining the health and good function of older adults. Despite being safe and a highly effective method of preventing certain infectious diseases, vaccination rates among older adults continue to lag behind national goals. Vaccines for older adults can be divided into three categories: those that are required for all older adults, those that may be required for special circumstances, and those that are required for travel. Physicians should be familiar with the indications, contraindications, and adverse effects of commonly used vaccines among older adults. This article will focus only on the vaccines required for all older adults.
Key words: vaccines, older adults, influenza, pneumococcal vaccine, herpes zoster, tetanus.

Vaccination Curtails Influenza Outbreaks, but Side Effects are Still Possible

Dr. Allison McGeer MSc, MD FRCPC
Director,
Infectious Control,
Mount Sinai Hospital,
Toronto, ON

Every year, approximately one in six Canadians are infected with influenza. Healthy adults infected with influenza miss, on average, 2-7 days of work, and have a 10-30% chance of being prescribed a course of antibiotics. Influenza causes approximately 20% of all cases of acute otitis media in children,¹ and is the most common single infectious cause of hospital admission in young children.^2-4 However, the greatest impact of influenza is seen in the elderly. Every year, nearly 1% of older adults with any chronic underlying illness require hospital admission due to influenza, and about 4000 die from influenza and its complications.⁵

Vaccination is the only effective method for the prevention of influenza. Annual vaccination is required because influenza viruses are able to mutate their antigenic coat continuously in order to evade the human immune system (see "Chasing Away the Flu Bug" on page 20 for a more detailed description of this process).

Lilia Malkin, BSc

Diabetes mellitus (DM) is estimated to affect approximately 1.5 million Canadians and 135 million people worldwide.^1,2 This article will review some of the recent advances in diabetes care and prevention, including non-invasive glucose monitoring, insulin delivery systems and "vaccination" to prevent the development of type I DM.

Maintenance of a physiologically appropriate blood glucose (BG) level is an essential component of diabetes control, as it has been shown to play an important role in reducing the debilitating sequellae of DM.^3,4 For many patients, good diabetes control may involve not only carefully planned meals, appropriate exercise regimens, and oral medications, but also interventions that may be invasive and painful, such as frequent BG monitoring and insulin injections. Decreasing or eliminating the discomfort associated with some of the more invasive procedures is likely to increase patients' compliance with therapeutic regimens, resulting in improved control of the disease.

The recent advent of minimally- and non-invasive BG monitors has the potential to replace, or at least decrease the use of the traditional "finger-prick" apparatus for the multitude of patients who require self-monitoring of BG levels.

Ruwaida Dhala, BSc, MSc

Vaccination has one of the greatest impacts on disease prevention. Most vaccines generate protective immune responses against a pathogen, preventing disease initiation. Often the immunity generated by vaccines to specific pathogens is lifelong. Preventative vaccines are not effective in cancer prevention, however, mostly because cancer antigens elicit poor immune responses. For this reason many cancers evade the immune system. Cancer vaccine strategy focuses on eliciting anti-tumour responses in patients that are already afflicted with cancer. These vaccines will presumably prevent cancer progression and reoccurrence rather than prevent cancer initiation.

In order for the body to mount an immune response, the invading pathogen, or components of it, must be exposed to the immune system. There are two major components of the immune system, humoral and cellular. Humoral immunity is involved in the generation of antibody responses. These antibodies are usually directed against extracellular pathogens such as bacteria. Most preventative vaccines rely on this arm of the immune system.