Immune responses to the latest shingles vaccine (Shingrix) last for at least three years following vaccination. The robust immune responses develop and persist in all age groups, according to a recent study in The Journal of Infectious Diseases.
In the study, Australian researchers show that the vaccine stimulates production of CD4 T cells to generate the robust and sustained response. The 24-fold increase in T cells induced by the new vaccine is 12 times higher than that for other less effective shingles vaccines, according to lead researchers Tony Cunningham, from the Westmead Institute for Medical Research in Sydney.
Humoral immunogenicity was assessed in 3,293 adults and cell-mediated immunogenicity in 466 adults who received two doses of the herpes zoster subunit vaccine as part of two clinical trials, one testing the vaccine in adults 50 years or older and the other in adults 70 years or older. A humoral response was achieved by 97.8% of the vaccine recipients compared with 2% of placebo recipients.
Antibody concentrations remained above the humoral response threshold in 77% of vaccines at 36 months following dose 2. “Humoral responses were elevated in all age groups, with anti-gE geometric mean concentrations only slightly smaller in participants 70 years and older throughout the 36 months of observation,” the investigators wrote.
The cell-mediated immunity response rate was 93.3% one month after the second dose, and then decreased to 57.2% at 12 months and remained stable through three years.
The vaccine efficacy was about 90% for all age groups. “This is quite remarkable because there are no other vaccines that perform nearly so well for people in their 70s and their 80s,” said Dr. Cunningham in a prepared statement. “What’s particularly exciting, though, is that 90% of recipients had an increased immune response sustained across the 3-year duration of the study. We anticipate that this protection will actually last much, much longer.”