Suzanne Humphries on chickenpox: what the evidence says · JRE #2294
SUBJECT: CHICKENPOX
Not a true/false call. Every claim is logged with its sources; read the exhibits below.
So it's been a detriment for measles and it's been a detriment for chickenpox. So chickenpox we used to get continuously. Adults didn't get shingles. It was very rare for adults to get shingles before the chickenpox vaccine came out.
What the evidence says 01 / RECORD
Shingles (herpes zoster) was common in adults long before the varicella vaccine, and its incidence had been rising steadily for decades before the U.S. childhood program began in 1996. A 60-year population-based study in Olmsted County, Minnesota found age- and sex-adjusted zoster incidence climbed from 0.76 per 1,000 person-years in 1945 to 1949 up to about 2.39 per 1,000 in 1990 to 1999, all before vaccination, with no change in the rate of increase before versus after the vaccine was introduced. A large U.S. database analysis likewise found adult zoster incidence rose 39 percent between 1992 and 2010 with no statistically significant acceleration after 1996, and incidence did not vary by state-level varicella vaccination coverage. The claim that adults very rarely got shingles before the chickenpox vaccine is contradicted by the surveillance record: the pre-existing, decades-long increase predates the vaccine, and studies find no substantial population-level impact of the vaccine on adult zoster.