How to read a vaccine study and Tobak et Al Ann Arbor influenza

what was the study of the Toback et al Vaccine paper

is the nasal spray flu vaccine (LAIV) safe for children age 24-59 months? bc an earlier study found more wheezing in younger kids

What was the methodology of the Toback et al: Vaccine

• followed 28,000 LAIV vax kids @ kaiser from 2007-2010

• excluded kids w asthma or high risk conditions

• compared them to three groups: unvax kids, kids w injected flu short (TIV), and same kids at diff. time windows after vax

• counted medical attended events (diagnosis tied to a medical visit), serious adverse events, and hospitalizations

What were the results of the Toback et al: Vaccine

• Asthma/wheezing was not increased and was actually lower in most comparisons

• No deaths, and serious adverse events were similar across groups

• Of 4,696 comparisons, 1.8% showed higher rates after LAIV and 4.7% showed lower rates. There was no pattern suggesting a safety problem

what were caveats in the Toback et al: Vaccine paper

• With so many comparisons, some “significant” results happen by chance

• The study was sponsored by MedImmune, the vaccine’s maker

• groups weren’t random

What is the key point the Raff blog post “How to read vaccine safety study” is trying to show

people should read beyond the title and abstract before criticizing a study