NOTTINGHAM, England — Waking up on the right side of the bed on the morning you go to get the flu shot might help ensure you survive the fall and winter influenza-free. That’s because a new study finds that simply being in a good mood when you get the flu vaccine actually boosts its effectiveness.
Researchers at the University of Nottingham in the UK examined 138 older adults, aged 65 to 85, over the weeks preceding and following receiving an influenza vaccination.

Participants moods, diets, physical activity levels, and sleep were evaluated three times a week for six weeks leading up to the vaccination. Four weeks after getting the flu shot, the research team measured the level of the influenza antibody in each participant, and then again at 16 weeks.
The only factor that showed any correlation to the shot’s effectiveness was mood. Those who were the most upbeat in the six weeks leading up to the shot showed the highest levels of antibody.
What stood out to the authors in particular was how influential a participant’s mood was on the actual day of the shot.  They found that those who were in good spirits on the day of their flu shot showed a greater level of the shot’s protective effects in subsequent weeks — accounting for up to 14% of the variability in antibody levels.
“We have known for many years that a number of psychological and behavioural factors such as stress, physical activity and diet influence how well the immune system works and these factors have also been shown to influence how well vaccines protect against disease,” says Professor Kavita Vedhara, from the university’s Division of Primary Care, in a press release.
Since the flu vaccine’s effectiveness varies year to year — the last two seasons it was about 48% effective, but just 19% effective in the 2014-2015 season, according to the CDC — these findings reveal a way to help ensure that one wards off illness, which is timely considering the recent commencement of fall.
Still, estimates show that getting the shot reduces the risk of the flu spreading among the general population by up to 60%.
Health officials highly recommend patients get their shots by the end of October. While the flu generally results in a fever along with upper respiratory symptoms, more serious health complications, including death, can occur among older individuals who contract it.
According to the World Health Organization, the flu kills 250,000 to 500,000 people a year.
The vast majority of fatal and non-fatal flu-related hospitalizations occur among those age 65 and older, the researchers note.
“Vaccinations are an incredibly effective way of reducing the likelihood of catching infectious diseases. But their Achilles heel is that their ability to protect against disease is affected by how well an individual’s immune system works. So people with less effective immune systems, such as the elderly, may find vaccines don’t work as well for them as they do in the young,” says Vedhara.
While previous studies had looked at individual variables that could influence the effectiveness of a flu shot, such as one’s nutrition, level of physical activity, or feelings of stress, no study had combined these factors, along with mood, into a more comprehensive inquiry.
It is believed that positive indicators on any one of these three variables may be correlated with improved mood, partially explaining why a good attitude may mean favorable flu shot outcomes.
The full study was published this month in the journal Brain, Behavior, and Immunity.