| Reduce varicella disease incidence, as compared to the pre-vaccine era |
Yes, by ~64% over an 80-year projection period * |
Yes, by ~86% over an 80-year projection period * |
| Reduce hospitalization |
Yes |
Anticipate further reduction |
| Reduce mortality |
Yes |
Anticipate further reduction |
| Reduce zoster incidence (all ages), as compared to pre-vaccine era |
Yes, by ~5% over an 80-year projection period * |
Yes, by ~11% over 80-year projection period * |
| Reduce zoster in the vaccinees |
Yes |
Anticipate further reduction |
| Reduce risk of secondary invasive Group A Streptococcus infection |
Yes (shown in the study by Patel et al.) |
Anticipate further reduction |
| Breakthrough disease (severity) |
Yes (in 7%–30%; the majority were mild cases) |
Yes, further reduction (in ~2%; all cases were mild) |
| Breakthrough cases can transmit infection |
Yes (especially if breakthrough disease is moderate–severe) |
Unknown (due to anticipated small number of cases) |
| Reduce outbreaks |
Yes, but outbreaks continue to occur in childcare centres and schools in the U.S. |
Anticipate further reduction (still too early to ascertain) |
| Antibody levels |
Lower seroconversion rates in post-licensure studies (after resetting the seroprotective titer to a higher level – see text) |
Significant boosting after the second dose whether administered 3 months later (2 doses of univalent vaccine) or 6 weeks to 4 years later (with 2 doses of MMRV) |
| Waning immunity |
Yes (based on outbreak studies) |
Anticipate less waning immunity (but rate of decline is unknown) * |
| Shift of varicella disease to older ages |
Shifted to mean of 22 years for wild type, and 41 years for breakthrough disease * |
Shifted to mean of 32 years for wild type, and 48 years for breakthrough disease * |
| Cost-effectiveness |
Cost-saving, for a single dose at 12 mos.* |
Cost-effectiveness ratios per QALY gained of 2-dose versus 1-dose vaccination: $106,000 (2 doses in the second year of life), $41,000 (2 doses at 12 mos. & preschool) and $28,000 (2 doses at 12 mos. & Grade 4), respectively *. |
