Can the flu jab give me flu?
It can appear that way, but the strictly accurate answer is no.
However, people may experience 'flu-like symptoms' such as aching muscles and joints or even a slight fever after a flu jab. This normally lasts for 1 or 2 days and feels similar to the start of a bout of flu.
The reason for this is that in some people, the viruses in the flu jab trigger a strong immune response because the body thinks that the infection is real. Immune chemicals are released as a result, leading to aching muscles and joints, headache and fever.
If you are experiencing any discomfort following the flu jab, it may be advisable to stretch your arm regularly to avoid any stiffness occurring, as well as ensuring you get enough rest and sleep and stay hydrated.
So, what is the flu jab and how does it affect the body?
The flu vaccination is an injection of viruses into the body. These viruses are grown in a laboratory and then killed so that they do not have the ability to reproduce themselves.
The strains of viruses found in the flu jab change every winter. At the start of each year, the World Health Organisation (WHO) looks at the viruses hanging around and picks a few suspects that are most likely to cause problems during the next Northern hemisphere winter.
So, the viruses present in the 2019 flu jab are:
• B/Victoria/2/87 lineage
• B/Yamagata/16/88 lineage
Although the viruses are 'dead' when introduced into the body, the purpose of the flu jab is to allow the cells of our immune system to see what these viruses look like. It is a bit like issuing 'wanted' posters of dangerous criminals – even if you have not previously come across one of these troublemakers, your body's immune system now knows what they look like, will recognise them quickly and will mount swift and strong action if they enter your body.
Who should have the flu jab?
Guidance from health authorities around the world suggests that people who are over 65, those with a significant underlying health problem and those vulnerable to infection should be vaccinated by their GP or local pharmacy in October or November each year. The reasoning is that, if infected, this group of 'vulnerable' people will suffer more severe symptoms and are more likely to develop complications.
In 2019/2020, the flu jab will also be offered to people considered to be at risk, including:
• Pregnant women
• People living in nursing homes
• Children aged 2-3 years
• All primary school aged children.
There are two different vaccinations this year which have been recommended by the NHS: Fluad for people aged 65 and over and the Quadrivalent vaccine for those aged 18-65. Research has shown the Fluad vaccine is more suitable in those aged 65 and over, however, both vaccines will protect against the flu.
What the flu jab does not do
The flu jab will not prevent you catching the common cold. Nor will it prevent infection by the many influenza viruses hanging around, other than those you are actually vaccinated against.
There is also another problem. Viruses that cause flu have a habit of changing their appearance. This process, known as mutation, is the reason why, on average, we suffer from 3 or 4 cold or flu infections each year. By contrast, the chicken pox virus does not tend to mutate and so it is unusual to get this infection twice in a lifetime.
The viruses in the flu jab look back at what caused problems 9 or 12 months ago. This means that it is unlikely to help with any 'new' viruses or mutated viruses arising out of the strains you have been vaccinated with.
So, what should I do?
As the flu jab will not give you protection from the majority of viruses encountered each winter, the key principle is to keep your immune system as strong as possible.
You will have heard the usual advice of watching your stress levels, ensuring plenty of sleep and having a good diet. Whilst seemingly obvious and mundane, this still stands as the best advice you can follow. If you are prone to infections, a vitamin supplement containing vitamins C and D and zinc, such as our immune support tablets, and Echinacea will help. As well as strengthening the immune system, Echinacea also has the advantage of direct anti-viral properties, as well as the ability to relieve the symptoms of colds, flu and upper respiratory tract infections.
So, we've come around full circle. If your immune system is strong, your body will be able to mount a healthy response to any virus invading your body. This is where the flu jab will help against the 4 viruses hanging around this year. If you are not vulnerable to infection you might, logically, fall outside the guidelines set by the government and perhaps there won't be any need for you to have the flu jab. If you are unsure about whether you should have the flu jab, ask your doctor for advice.
Originally written 30 October 2014 (updated 4 November 2019)