If you start taking an antiviral medication after catching the flu, will it keep your family members from catching the bug, too? Maybe not, according to a study in The Journal of Infectious Diseases.
The prescription antivirals oseltamivir (Tamiflu) and zanamivir (Relenza) can cut a case of the flu short by suppressing the virus's overpowering urge to copy itself inside you. Less viral "shedding" by the body could, hypothetically, make it less likely that people who live in the same house will also get sick.
The study tracked 582 people, both adults and children, recruited at outpatient clinics in Hong Kong, with flu symptoms that had started within the past 48 hours. People who started taking the prescription flu-stopper Tamiflu within 24 hours of their first symptoms (38% of the total) cut the duration of fever and other symptoms by about half.
Study participants had contact with an average of three household members. Unfortunately, prompt treatment with Tamiflu did not appear to reduce flu transmission to these innocent bystanders.