When the shingles vaccine was being researched and developed, the patient population was studied for five years. These initial studies showed the vaccine to be 90 percent effective after five years.
Based on that research it was therefore felt that Zostavax (shingles vaccine) could be given once in a lifetime. Unfortunately, it is starting to look like that won’t be the case.
Now that longer-term studies are being completed, it is apparent that immunity wanes with time. In fact, efficacy falls to 46 percent after seven years; 14 percent after 10 years, and roughly zero after 11 years.
Since these long-term research projects have just been completed, the medical community awaits advice from the Centers for Disease Control and Prevention (CDC) regarding re-vaccination protocols.