Anyone who has recovered from the chickenpox may develop shi…
Anyone who has recovered from the chickenpox may develop shingles, which is very painful, thus the CDC recommends that people 50 years and older get the shingles vaccine. There are two types of shingles vaccine: 1) Zostavax, a live vaccine, and 2) Shingrix a newer recombinant vaccine. Researchers wished to determine whether Shingrix better reduced the risk of shingles in people over the age of 50 as compared to the currently used vaccine, Zostavax. The researchers recruited 1330 participants over age 50 for the study. During routine visits to their primary care doctors, individuals were randomly assigned to either the Shingrix group or the Zostavax group, with 720 people receiving the new Shingrix vaccine and the remaining people vaccinated with Zostavax. In the group that received Shingrix, 27 people developed shingles within a 5-year period. In the Zostavax group, 81 people developed shingles during the same time period. What type of study is this? How do you know?