I am beginning to think that this pandemic won't end --> now focussed on vaccine booster timing questions

The Quarantine Zone
82

In discussion about medical policy, it’s valuable to make a distinction between “That’s the way we always do it” and “This is the way we should do it”, rather than just advocating doing it the way we always do it, and hoping for the best.

Yes, other ways could provide a bigger benefit. If they work better, they could reduce problems and save resources.

This isn’t a one-sided argument: smart people look at the two sides of the equation and make different judgements, and they aren’t immoral, corrupt or imcompetent for disagreeing with each other on the basis of the same evidence.

83

I just moved a bunch of posts here from

some of the posts refer to prior posts by number – that would be post numbers in the other thread.

I also changed the name of this thread. The original topic had sort of died out, and this topic that was originally a sidetrack seems to be of a lot of interest, now.

84

I don’t think anything could be further from what I am saying. I’m not appealing to tradition, I’m saying we need to rely on science. Like this (posted earlier):

Of course. As long as “both” (or all) sides are relying on evidence and expert analysis, not just saying, "I’m a smart person, so I can put my opinion up against the experts who have the actual data and the expertise to interpret it.

If there are experts with the available data coming to different hypotheses and conclusions and recommendations, then there’s nothing wrong with those different approaches.

85

We don’t actually know how long immunity from any of these vaccines will last, because we haven’t been able to test them for very long.

86

I get what you’re doing - makes sense; this one also belongs here, then:

So: about these COVID variants - we’re going to have to tweak existing vaccines in order to provide protection against them, right? But how do we test the revised vaccines for efficacy before they are made available?

The European Medicines Agency released a reflection paper [Link is to PDF] today - a reflection paper being pretty much what it says - the agency is sharing its thoughts with us; in due course, and taking account of comments from medical, industry and other experts, this will become a guideline which tells you what you have to do.

The (current) EMA position is that no large scale efficacy studies will be required; approval of the updated vaccine - presuming that it is formulated, manufactured, tested etc etc like the “parent” vaccine was - will be based on human immunogenicity studies. Basically, trial subjects get a shot of the vaccine, their immune response gets tested to show that the new vaccine does the same thing against the new strain, compared to old vaccine/old strain. The paper covers combi vaccines (old + new in a single shot) - the approach is similar but (obviously) a bit more complicated. Safety data for authorisation would come from the subjects included in these studies.

The FDA moved faster (I was a couple of days late getting to this) and have already revised existing guidance. As you would hope, they are thinking pretty much along the same lines as the EMA. Link to announcement (from which you can hunt down the guidance document, if you wish).

The updated guidance outlines the FDA’s scientific recommendations for modifications to authorized vaccines. For example, the FDA expects that manufacturing information will remain generally the same for an authorized vaccine and a modified vaccine candidate from the same manufacturer. For clinical data, the guidance recommends that a determination of effectiveness be supported by data from clinical immunogenicity studies, which would compare a recipient’s immune response to virus variants induced by the modified vaccine against the immune response to the authorized vaccine. Manufacturers are also encouraged to study the modified vaccine in both naïve (non-vaccinated) individuals and in individuals previously vaccinated with the authorized vaccine. Additionally, the guidance outlines the FDA’s recommendations for assessments of safety to support an EUA for a modified vaccine. Finally, the guidance states that further discussions will be necessary to decide whether in the future, modified COVID-19 vaccines may be authorized without the need for clinical studies.

Obviously this is just a very brief summary of the documents. If you have questions, I can try to field them, but I’m not an immunologist. @BippityBoppityBoo - you may be better than me in that area (it wouldn’t be difficult!)*.

j

(*) - Answered by BBB in post 80

87

Yeah, hypothetically, I maybe should have started a new thread. But this one had a lot of relevant content, and the initial topic had sort of run out.

88

That would include insisting that a vaccine is strongly likely to become useless after a month. I have seen no experts suggest that – only caution that we don’t know when immunity might drop off.

89

Good news: there are people out there doing just the sort of coordinated international planning that you would want done.

When I posted the (proposed) guidance docs for new vaccines for the new variants, I had it in the back of my mind that there had been some sort of meeting recently. I dug out the details just now. It was a meeting of the International Coalition of Medicines Regulatory Authorities, jointly hosted by the US and the EU.

The ICMRA workshop was organised in light of the possible spread of these new variants globally and the need to consider rapid updates of current vaccines. The objectives were to discuss current surveillance activities to monitor the spread of the variants, and minimal elements of data that would be required to swiftly approve updated versions of available vaccines against emerging variants of SARS-CoV-2.

The European Medicines Agency has released a summary minute of the meeting: here it is. It was immediately after this meeting that the EU and US guidance documents were published. A couple of highlights from the minute:

Assuming that much of the manufacturing process and controls, as well as the facilities for vaccine production, for the variant COVID-19 vaccine would be identical to that of the prototype COVID-19 vaccine and depending on platform specific aspects, data to be generated may be confined to critical aspect of product characterization, potency assay and stability.

That is to say: just tell us about the bits you’re doing differently. Everything else we’ll take as good.

Inference of efficacy would need to be supported by conducting clinical non-inferiority immunogenicity studies comparing the immune responses induced by a variant COVID-19 vaccine against the SARS-CoV-2 variant of concern to the immune responses induced by the prototype vaccine for which clinical studies demonstrated efficacy and when administered according to the authorized dose and dosing regimen.

No (big, slow) clinical efficacy studies. Is the immune system response for new variant/new vaccine the same as for Original SARS/original vaccine? Yes? Then we’re good to go.

j