What is shingles?
Shingles is caused by the varicella-zoster virus, the same virus responsible for chickenpox. Around 95% of adults in Ireland have had chickenpox, and for all of them, the virus never fully leaves the body. It lies dormant in the nervous system and can reactivate later in life as shingles.
One in three people will develop shingles in their lifetime, and the risk increases with age. The immune system naturally weakens as we get older, making reactivation more likely. Stress, illness, and certain medical conditions or treatments such as cancer or HIV can also trigger it.
When shingles does occur, it starts with pain and tingling before developing into a rash with blisters, usually on one side of the upper body. This can also appear on the head, neck, or around the eyes. The rash typically lasts two to four weeks, but shingles can be significantly more severe in older adults.
One of the more serious complications is post-herpetic neuralgia (PHN), persistent nerve pain that continues long after the rash has healed, sometimes for months or years. The older you are, the higher your risk of developing PHN.
How effective is the Shingrix vaccine?
The shingles vaccine currently available in Ireland is Shingrix, a recombinant vaccine given as two doses, two to six months apart. Research shows it is highly effective:
- Ages 50 to 69: 97% effective at preventing shingles, 91% at preventing PHN
- Ages 70 and older: 91% effective at preventing shingles, 89% at preventing PHN
- Ages 18 to 49 with a weakened immune system: 68 to 91% effective, depending on overall health and underlying conditions
Even if you do develop shingles after vaccination, the vaccine can reduce the severity and duration of symptoms. In people with healthy immune systems, protection lasts at least seven years. There is currently no booster available.
If you have had shingles before, you can still be vaccinated, provided it has been more than one year since your last episode.
Emerging evidence on dementia
The benefits of the Shingrix vaccine may extend beyond shingles. Emerging research suggests a link between the shingles vaccine and a reduced risk of dementia.
A 2024 Oxford study in the US and a 2025 Stanford study in Wales found that vaccinated adults are up to 20% less likely to develop dementia. Research is ongoing, but the findings are compelling.
You can read more about the research at the link below:
https://med.stanford.edu/news/all-news/2025/03/shingles-vaccination-dementia.html
Who should get the shingles vaccine?
The vaccine is recommended for adults aged 50 and over. It can also be given to adults aged 18 to 49 who are at increased risk due to a weakened immune system.
You may be at greater risk of developing shingles if you:
- Are aged over 50
- Have a weakened immune system
- Have recently been ill
- Are under significant or prolonged stress
Who should not get the shingles vaccine?
The shingles vaccine is not recommended during pregnancy. If you are breastfeeding, speak to your doctor before proceeding.
You should not receive the vaccine if you have a history of severe allergic reaction to any of its components. If you have thrombocytopenia or a coagulation disorder, speak to your pharmacist, as you may not be eligible to receive the vaccination in a pharmacy setting.
Allow at least seven days between a COVID-19 vaccination and the shingles vaccine.
What are the side effects?
Most side effects are mild and resolve within a few days. These can include:
- Very common: headache, nausea, vomiting, diarrhoea, stomach pain, muscle pain, pain or swelling at the injection site, fatigue, chills, fever
- Common: itching at the injection site, general feeling of being unwell
- Uncommon: swollen glands in the neck, armpit or groin, joint pain
Therefore we ask you to remain in the pharmacy for 15 minutes after your vaccination in case of any immediate reaction. In the unlikely event of a severe allergic reaction, signs include hives, facial or throat swelling, difficulty breathing, rapid heartbeat, dizziness or weakness, our pharmacy team is trained to respond.
If a chickenpox-like rash develops after vaccination, avoid close contact with people who have not had chickenpox until the rash is fully dry and crusted.
