Swine flu is less contagious than previous pandemics, according to a new study.
According to the WebMD.com report, the study examined 216 households consisting of two to six persons in which one family member had a confirmed case of the H1N1 disease.
Just 13 percent of family members caught the flu from the infected relative.
That's an average figure, with the transmission rate being higher - 28 percent - in two person families, and lower - just 9 percent - in households with six persons.
The flu affects younger people more often than old. Those aged 18 or younger were twice as likely to catch it from a family member as people 19 to 50. Those over 50 were a whopping 80 percent less likely to get the bug than the youngest group in the study.
"Our results underscore the critical role children play in the unfolding pandemic," the New York Daily News quoted study author Simon Cauchemez and his colleagues.
The study also showed that when a family member did catch H1N1, their symptoms appeared two to four days after symptoms appeared in the first affected family member.
On average, the second person in the household to get it came down with symptoms 2.6 days after the first person showed symptoms.
The study appears in the Dec. 31 issue of the New England Journal of Medicine.