How shingles vaccine works
After someone has had chickenpox, the virus stays in their nerve roots, dormant, for the rest of their life. It is held in check and controlled there by the immune system. With advancing age our immune system deteriorates. The virus can then become reactivated and cause shingles.
Shingles vaccine strengthens the immune system’s defence against the chickenpox virus, and thereby prevents the virus from being reactivated and causing shingles.
As with all vaccines, shingles vaccination does not lead to complete protection for everyone vaccinated. However, among those vaccinated who do develop shingles the course of the disease becomes less severe and the risk of long term nerve pain as a complication is decreased.
If shingles has already developed, the vaccine cannot cure the disease. The shingles vaccine is preventive and must be given before the illness appears to be effective.