Difference between third dose and booster

[PinkWednesdays]

I’m struggling to understand the difference between a third dose and a booster. Does anyone know

Google tells me a third dose is just that, another dose, whereas a booster is intended to boost the previous doses. That makes sense but what does it actually mean?

Is a booster a smaller dose, or is there something else in the booster?

I’m just curious, as I was having this discussion with my parents who were talking about a third dose and a booster interchangeably, and we realised we didn’t know the difference in practical terms.

@ChessieFL

The booster is half the dose of the third dose e.g. 0.25 of the active ingredient instead of 0.5 or whatever.

Only for Moderna. Pfizer booster is full dose.

I wonder why on the government site they lump all additional doses into the same catagory? Really they should distinguish between those with a booster and those who've had a third primary dose since they are different things?

I had AstraZeneca for my first three then my fourth was Moderna.

@mynameiscalypso you have to go to a clinical setting for the booster. I went to a walk in at a community centre for my fourth and they wouldn't do it. I had to go to one where a GP was on duty.

@containsnuts they wouldn't know as all third doses have gone down as boosters.

A third dose is offered to the immunosuppressed, they will then be offered the booster later on. They get extra to support their immune system.

This issue is actually affecting me.

I have had 2 full dose primary vaccines of Pfizer.
In November I had my booster. I wasn't given a choice of vaccine - I was given a half dose (booster) of Moderna.

In December I've received a letter from the hospital telling me I need 3 primary dose of vaccine plus a booster.

I'm now in a situation where I don't know what happens in February.
I'm seeing the gp soon and in the new year will need to call the consultant to see if they can clarify what I should do, as I've had the wrong doses.

I haven't had the 3 full primary doses that I should have had, due to the Moderna booster being a half dose. So I have no idea what I should be having when I go for my fourth jab.

In the pamphlet I got when I had my booster they wrote it as 'third dose (booster)' so I thought they were the same. Maybe some say third dose if it was the same vaccine? I had A Z first two then Moderna.

Third dose is definitely different to booster.

Only a small percentage of our population are invited to have a third dose. You can only have a third dose with a letter stating you are eligible. These people will have 4 doses in total, over a year.

"3rd covid booster" implies I've already had two boosters?

Should it not say "booster" I'm autistic I may be looking too much into it.

@onedayoranother

In the pamphlet I got when I had my booster they wrote it as 'third dose (booster)' so I thought they were the same. Maybe some say third dose if it was the same vaccine? I had A Z first two then Moderna.

There was a stage where government (and Prof Spector if I remember correctly) were actually referring to boosters as third doses in order to encourage up-take. The explaination at the time was that the course was incomplete with only two doses.