You can’t get influenza from a flu shot – here’s how it works

[AussieNeil]

..while you might sometimes get sick after having a flu shot, it’s a myth that having a flu shot can give you the flu

:

How the immune system fights the flu

The human immune system has several strategies to protect against infection. For viral infections such as influenza, the key strategy is known as adaptive immunity. This part of the immune system can “remember” previous exposure to pathogens.

When you get an influenza infection, the virus enters and hijacks the machinery of the host cell to replicate itself, before releasing these copies to infect more cells.

T lymphocyte cells of the immune system can recognise this viral incursion. T cells protect against further spread of the virus by activating pathways that cause infected cells to trigger a “suicide” process.

Another strategy the body uses is to produce antibodies, which are molecules produced by B cells that recognise components of the viral capsule. These antibodies work by sticking to the surface of the influenza virus to prevent it spreading and facilitating disposal. This is why it is important to be up to date early in your CLL - and definitely before commencing any treatment. You need healthy B-cells which all CLL treatments remove, to be able to make antibodies: See healthunlocked.com/cllsuppo...

Flu shots help mount a quicker defence

On a first exposure to a pathogen, our B cells take at least two weeks to ramp up production of antibodies. However, on subsequent challenges, antibody production occurs much more quickly.

Influenza vaccines harness this arm of the immune system, known as “humoral” immunity. By “practising” on viral components, vaccines allow the immune system to react more quickly and effectively when faced with the real virus.

Allen Cheng, Professor in Infectious Diseases Epidemiology, Monash University and Katherine Kedzierska, Academic, Microbiology and Immunology, University of Melbourne, give four reasons why you may feel sick after a flu shot: theconversation.com/you-can...

Note the conclusion: ..studies have consistently shown that vaccinated people are less likely to get influenza or complications from the flu than those who aren’t vaccinated.

Neil

(This is an unlocked post)

Photo: Some of us stick to old beliefs against the tide of new information

[Mystic75]

As always, thanks Neil for the explanation!

[lexie]

This will be handy for those times I get into a discussion with someone who is convinced the flu shot will give them the flu. Thanks for the ammo, although I promise to be diplomatic.

I love that photo. Is there a backstory on that? Gastropods?

[AussieNeil Partner Administrator in reply to lexie]

Yes, people can be very insistent that they caught the flu from the flu shot, even if the timing isn't right!

I took that photo when recently revisiting seaside rock pools regularly enjoyed when I was a teenager.

[Big_Dee in reply to AussieNeil]

Hello AussieNeil

I am glad you explained the picture, I thought it might be a microscope picture of a flu virus.

[Panz]

Neil, I was also told that the annual flu shot was a great way to stimulate my very compromised immune system and for that reason alone it was very important to get it as early as it was available and every year!

😍🙏💕

[Zia2]

Thanks for the post. Although not 65 my CLL specialist has me receive the high dose flu shot each October (in the US). Thoughts about the difference? Is it just more ?

[AussieNeil Partner Administrator in reply to Zia2]

I'd be interested in what others have heard about the effectiveness of the high dose version for those with CLL, as I seem to recall mixed responses. You may be better off having two flu shots per year, to both extend coverage and take advantage of updates in the serotypes covered (if done). The flu season seems to be lengthening.