Did you know that almost 30% of all adults will develop shingles within their lifetime? And did you know that by the age of 85, 50% of the population will be affected?
Post-herpetic neuralgia (PHN) is the most common complication. This is the pain caused by shingles, which lasts after the rash has healed. The pain can last for several months or even years and reduces the quality of life, especially in the elderly.
Older age and immunosuppression are the most important risk factors for shingles and PHN. The incidence rates of shingles consultation increase further around the age of 50 and are particularly high after the age of 70. PHN occurs in approximately 20% of adults with shingles and increases with age.
Shingles often begins with localized pain that lasts a few days (4 to 5 days). Then the pain increases, and turns into a rash. The pain becomes deep and constant, and is accompanied by a burning and stinging sensation. This acute stage lasts for about 4 weeks, but post-herpetic neuralgia can last for months, and even years.
It is estimated that in Quebec, each year, there are approximately 27,000 cases of shingles, 600 hospitalizations and 10 deaths caused by the disease. The majority (≈ 80%) of deaths occur in people aged 80 and over.
The impacts on quality of life can be major: fatigue, anorexia, weight loss, physical inactivity, insomnia, depression, anxiety, loss of concentration, reduction in social activities, loss of functional skills such as dressing, eating, moving around, etc.
So the big question is: can we prevent shingles and post-herpetic neuralgia? The answer is YES: Immunization.
Two vaccines are available in Canada: the live attenuated zoster vaccine Zostavax licensed in 2008 and the subunit vaccine Shingrix licensed in October 2017. Both vaccines are safe and effective in reducing the incidence of shingles and PHN.
The effectiveness of the live attenuated vaccine in preventing shingles is approximately 50 to 70%. It decreases with age at vaccination and the time since vaccination. According to the manufacturer, even in those who have received the vaccine and who will develop the disease, pain will be reduced in 73% of patients compared to placebo.
The effectiveness of the subunit vaccine in preventing shingles is approximately 90% in all age groups and remains relatively stable for at least 4 years. The persistence of high antibody levels measured 9 years after vaccination suggests long-term protection.
Who should get vaccinated? As a pharmacist, I suggest the following strategy in accordance with the recommendations of the National Institute of Public Health of Quebec (INSPQ):
- People aged 50 and over AND immunocompromised as defined in the Quebec Immunization Protocol. These people have a high risk of developing shingles and PHN. Unlike the live vaccine, the new inactivated vaccine, Shingrix, is not contraindicated in immunocompromised people;
- People aged 65 and over;
- If it is not possible to target all people aged 65 and over, the Conseil Interprofessionnel du Québec (CIQ) recommends offering vaccination to people aged 70 and over. In this age group, the risk of shingles and that of PHN is particularly high. Vaccination in this age group will reduce the burden of disease more quickly;
- People aged 50 to 64. The burden of shingles begins to increase at these ages, but is not yet maximal. Vaccine efficacy data are available for those aged 50 and over for a minimum of 4 years. However, the duration of the vaccine efficacy could be an issue for this age group, particularly for the live attenuated vaccine. After 4 years, it is not yet determined whether a revaccination would be indicated, and indeed an additional injection may be necessary;
- The current state of knowledge does not allow recommendations to be made for people under the age of 50;
Considering that the risk of getting shingles increases with age, and given the major disadvantages of the symptoms it causes, I believe that patients should be informed by health care professionals that vaccines are available for this purpose.
Consult your doctor or pharmacist to find out if a vaccine would be recommended for you or if there is a contraindication in your case.