Annual vaccination is recommended in most cases
Now that summer is over, the flu season is fast approaching.
Flu is a highly contagious virus (influenza) that is spread by droplets that are released when we cough and/or sneeze. In densely populated urban areas such as Tokyo, flu spreads rapidly during the winter months.
Flu symptoms are usually much worse than those of a bad cold and can involve several days off work or school.
Also, certain groups of people are at high risk of developing complications from the flu, such as bronchitis or pneumonia. Serious complications such as these can result in hospitalisation and even death.
Those at increased risk of complications include children under five (especially the under-twos), adults over 65, pregnant women and people with chronic health conditions, such as asthma and diabetes.
Recommendations regarding vaccination vary from country to country.
In England, flu vaccination is currently only offered to some high-risk groups, although the National Health Service plans gradually to expand the programme to include all children from age two to 16.
In the US, flu vaccination is recommended for all aged six months and older. Here are some common questions regarding the flu shot I encounter in my daily practice.
Why do I need to have a flu shot every year?
The flu virus can easily mutate, so circulating strains vary from year to year. Based on global surveillance, the World Health Organization decides which viral strains should be included in the annual recommended flu shots.
Can the flu shot actually give me flu?
No, it can’t. The flu shot contains inactivated forms of the virus, so it cannot give you the flu or any other infection. People sometimes catch a common cold around the time they get a flu vaccine; this is just bad luck and coincidence.
What side effects can I expect?
You may experience some soreness at the site of vaccination, a mild fever or muscle aches. However, these usually only last for a couple of days.
How effective is the flu shot?
Unfortunately no vaccine is 100% effective, so there is still a chance of getting the flu. The effectiveness of flu shots depends on the match between the viral strains in the shot you are given and those circulating in the community.
If the match is very close, the vaccine can be quite effective. Even in years when the match is low, if you do get the flu, the symptoms are likely to be milder than if you hadn’t had a flu shot.
Also remember that flu shots are specific to the flu virus—they will not protect you against the common cold.
Are there different types of the vaccination?
Yes, the vaccination is available as an injection and also as a nasal spray.
The nasal spray is most commonly used for children from the age of two as well as other patients up to 49 years old.
Children under two and older than six months can only receive the injected flu shot. The spray has the obvious benefit of being needle-free, and in children it has been shown to be more effective than the injection.
Is it safe for women who are pregnant to get the flu shot?
Yes, the injected form of the flu vaccination is safe at any stage of pregnancy.
In fact, pregnant women are at increased risk of complications if they do get the flu, so most countries actively encourage the vaccination of women who are pregnant or planning on being pregnant during the flu season.
Some protection will also be passed to the baby, which will last for a few months after birth.
Newborn babies less than six months old are too young to be vaccinated, but they are at high risk for serious flu complications. So it is also important for dads-to-be, older siblings, babysitters, and other people in contact with babies to get vaccinated to protect newborns.
I’ve already had influenza this season, so do I still need to get a flu shot?
Since there are several different strains of flu, you could still become infected by a different strain later in the season.
Also, what you may have thought was influenza could just have been a bad cold. So yes, you should still get a flu shot.
October is a good time to get your flu vaccination since immunity typically takes around two weeks to develop and the flu season runs from around November to April.
Finally, remember that other simple actions, such as frequent hand washing with soap and water, can also help protect you from the flu.