During National Influenza Vaccination Week comes news that over-the-counter medications are not useful in fighting the flu virus or in reducing a person’s temperature or other symptoms. The newly published clinical trial results run contrary to the advice physicians often give their patients who have the flu.

The study included adults aged 18 to 65 years with confirmed flu. They were treated with the maximum recommended does of acetaminophen for five days and were monitored for up to 14 days.

“We initially theorized that taking [acetaminophen] might be harmful, as the influenza virus cannot replicate as well at higher temperatures, and by reducing a person’s temperature, the virus may have thrived,” said Irene Braithwaite, co-author of the study, which appears in the journal Respirology. “Fortunately this was found not be the case. In this study, [acetaminophen] was not harmful, but we also found that [it] was not beneficial either,” added Braithwaite, of the Medical Research Institute of New Zealand.

Although acetaminophen may not help those who have the flu or a flu-like illness, Braithwaite reaffirmed the importance of the flu vaccine. “One of the things we need to take from this … is that those at risk—particularly pregnant women, the very young, the old and those with chronic medical conditions—should have the annual influenza vaccination, as it confers the best protection available against the influenza virus,” she said.