Influenza can ruin Christmas, leaving us in the bed shivering away from the fun.
Half of us had to cancel celebrations because of the virus, a Boots study found. And a quarter is too painful to drink in Turkey on Christmas day.
But staying current should see you through the holiday season as it takes two weeks for protection.
Experts Dr Richard Dowd, of the Fleet Street Clinic and virologist Prof John John Oxford of Queen Mary University in London, established the facts.
How the section works
Prof Oxford said: "Flu vaccination stimulates your body's immune system to make antibodies that fight bacteria.
"Antibodies stay in your body, so if you are exposed to the flu virus after you have been vaccinated, the immune system will recognize it and produce more antibodies to fight it."
Even if you were vaccinated last year, it's important to go again because the circulating strains of the virus change every year.
Who should get it?
People who are more prone to complications from the virus have the right to release the flu from the NHS flu. This includes people over 65, people with chronic medical conditions, such as type 1 diabetes, those with weakened immune systems, and pregnant women.
But Dr. David explained that it is important to vaccinate those who can get in touch with many people, such as medical professionals.
Statistics show that children are vaccinated, the circulation of the disease is reduced because they do not spread it so poorly with hygiene.
He added: "Older people are much more susceptible to harmful complications like pneumonia. Children can also be affected by complications. The outbreak of swine flu has opened our eyes to the seriousness of what can happen.
"In that case, it became clear that pregnant women were likely to die of complications from the flu."
But the flu flu is for anyone who wants to avoid being puffed up by the disease.
Those who are not eligible for NHS netting can get it for £ 12.99 at selected boots pharmacies or in specialized private clinics such as the Fleet Street Clinic, which also vaccines children.
What the virus can do
The effects of influenza can range from mild colds to fever or pneumonia.
Dr David said: "At the low end there are almost no symptoms, just a little bit of weather.
"The typical flu is three to five days of feeling feverish and sick and stagnant.
"It should be improved normally, but in a small number of people it will improve."
This opens the gates to bacterial infections and more serious lung conditions.
Dr David says you can get a painful hand at the rate.
He said: "The side effects of the pulp are much, much less than the flu itself.
"Most people get nothing but they may feel some pain from the injection site.
"You can't catch the flu from getting the flu."
The vaccine offered to children is scattered throughout their nose, so they do not have to worry about needles.
How effective is it?
Flu gaps depend on expert teams predicting which species are likely to hit the UK during the flu season.
However, to begin vaccinating everyone in time for the winter, cuts should start in September, meaning they were made earlier in the year.
Sometimes the virus can be changed or another hit of the virus. But this is not the case when transmission is inefficient, it is just impossible to predict 100% correctly all the time.
Dr Dood added: "Influenza is really a cheap, effective way to prevent many people getting sick in the winter."
■ Boots offer 10% off the flu service if you book online today at boots.com.