What's happened to AZ vaccines?

[parsleydog]

Are they still being made/offered/planned?

Seems like all the boosters are Pfizer or Moderna and I just read a Guardian article saying the government has ordered millions more Pfizer/Moderna vaccines for 2022/2023 at huge expense.

Is it because AZ isn't as good? Have they dropped it (in this country)??

I believe 2 AZ gives little if any protection against symptomatic Omicron, though may give more against severe disease.
It wouldn't seem logical to keep using it if omicron is set to be dominant within days but I don't know whether they are still giving it.

The booster studies showed that the mRNA vaccines gave better antibody responses than AZ (as boosters) so it was never planned to use them for boosters unless people couldn't have the mRNA ones for medical reasons, even before omicron. (Putting aside the fact that the AZ ones may give better T cell responses according to some data).

so basically everyone to be hooked on mRNA

AZ was also not to be given to those under 40 due to the risk of blood clots wasn't it? So I suppose it makes sense that it would be phased out if it couldn't be used by everyone.

Yeh, I'm over 40 and only had AZ.

AZ do not produce vaccines in their normal course of business. When the first global pandemic hit they went outside of their normal business lines and threw resources at developing a vaccine, which was why it was developed in tandem with Oxford scientists.

My understanding is that the type of vaccine that they (AZ) developed works in the same way as a flu jab- injecting a weakened strain of the virus so that your immune system learns how to fight it.

The Pfizer and Moderna jabs work differently- they are messenger RNA vaccines which teach the body to produce SARS protein and have the body break it down. This is the first time that mRNA vaccines have been fully licensed and widely used, although they have been used in cancer trials for many years.

AZ were able to get their vaccine developed quicker as it used a familiar regulated technique and was easier to distribute so that is why it was so widely used for the first roll out. The downside of this type of vaccine (same as the flu jab) is that it needs to be updated for each particular strain so can be less effective as covid mutates.

The Pfizer / Moderna vaccines seem to be working better against the mutations because of the way they teach the body to fight the SARS, and there has been enough time to develop infrastructure to transport the vaccines which need cold storage so I think this is why AZ are not being used for the boosters.

Also I personally think that AZ tried to do some good and ended up with a massive backlash for it and have decided not to further pursue vaccine development and are concentrating on their usual business which is oncology, cardio and respiratory drug development.

My understanding is that the type of vaccine that they (AZ) developed works in the same way as a flu jab- injecting a weakened strain of the virus so that your immune system learns how to fight it.
Your understanding is wrong. The AZ vaccine uses an adenovirus vector, there is no attenuated virus involved. One of the issues with AZ is that there was always a risk of people developing antibodies to the vector virus so it was possibly never a long term solution.
The AZ vaccine was a fantastic one which has saved countless lives. Yes there was a problem with blood clots for a tiny minority bit it did a great job at doing what it was designed to do, and cheaply as well. It's ashame they had poor PR.

Thanks everyone.

I also think AZ did an amazing job and the whole non-profit thing was utterly inspirational. Which is why it seems a bit of a shame, especially because Rishi Sunak seems to be wondering about where the money is going to come from for all the Pfizer/Moderna vaccines for next year (and the year after...)