Vaccine Trials

[gerntz]

Now AstraZeneca vaccine showing good efficacy. Not as high so far as first two. Uses different mechanism to deliver also. And can be stored with just refrigeration. Still a two shots system.

 

[Chuckanut]

If you can get a 95% effective vaccine and you are in the highest risk group, what are the chances tht you will go without a mask among Covid-ineffected people?

Emphasis added.

I would say if I was that person, I would wear a mask, but I would also feel much better in the event I found myself in a group of unmasked folks without my own mask. Even a 1 in 20 chance of infection is not that great for highest risk people. Just my 2¢ based upon the very little I know.

 

[explanade]

If you can get a 95% effective vaccine and you are in the highest risk group, what are the chances tht you will go without a mask among Covid-ineffected people?

Emphasis added.

I would say if I was that person, I would wear a mask, but I would also feel much better in the event I found myself in a group of unmasked folks without my own mask. Even a 1 in 20 chance of infection is not that great for highest risk people. Just my 2¢ based upon the very little I know.

Not only that, there's a belief that vaccines, at least the early ones, will prevent disease but not necessarily infections.

The assumption is that the vaccines won't raise an immune response effectively in the parts of the body where you get infected, which are the nasal passages, mouth and possibly the eyes.

What they would do is prevent infection from spreading and taking hold in your lungs and other organs like the heart.

For the upper respiratory tract, there are vaccines and drugs being developed which would be delivered as inhalers, to attack the virus in those areas.

That also means while you are less likely to get sick, you can get infected and be infectious to other people.

 

[audreyh1]

DW and I functionally unblinded our phase 2 Novavax trial today. We apparently beat the odds and are both in the control group based on negative results from the Assure rapid antibody test which has 99% specificity.

So no gym or indoor pickleball this winter. Looking forward to availability of the Pfizer or Moderns version.

Yes, thanks for your contribution! And I hope you have access to a vaccine soon!

 

[Montecfo]

Now AstraZeneca vaccine showing good efficacy. Not as high so far as first two. Uses different mechanism to deliver also. And can be stored with just refrigeration. Still a two shots system.

Looks like there may be quite a few paths to beating Covid, and coming to market pretty quickly.

 

[CaptTom]

That also means while you are less likely to get sick, you can get infected and be infectious to other people.

Oooo. I hadn't thought of that. That's a bit of a bummer. I was thinking about the vaccine as a sort of "super power" that would allow me to relax a bit.

OTOH, at some point everyone who wants one will have the vaccine, and only those who would rather get sick than take the vaccine will be at risk. I'm going to have a hard time working up a lot of sympathy for those folks.

 

[sengsational]

That also means while you are less likely to get sick, you can get infected and be infectious to other people.

The term I've heard for a vaccine that makes it so you can't infect someone else after the vaccine has trained your body to recognize it is a "sterilizing vaccine". No current Sars-CoV-2 vaccine claims to fall into this category. But in my thinking (warning, he's doing it again!), if your body recognizes some virus that enters your body and starts eliminating it right away, there won't be nearly as many virus particles created, and fewer particles to share on your exhales or within your shared 'bodily fluids'.

 

[Chuckanut]

If the vaccine helps with herd immunity, it has to be doing something that keeps the virus from spreading at its normal rate.

 

[Teacher Terry]

We will definitely be getting the vaccine so we can get our lives back. We will probably be in the second group being older with health issues. We are glad we got out some this summer. In light of the cases rising everywhere I am surprised people are traveling for the holiday. We sat outside today with a high of 48 degrees to visit with my son and his wife. Masks were worn and we sat far apart. We lasted 90 minutes until we were frozen).

 

[Alan]

If the vaccine helps with herd immunity, it has to be doing something that keeps the virus from spreading at its normal rate.

My thoughts as well. A spokesman from AstraZeneca yesterday said that they are geared up to produce 3.5 billion doses worldwide next year. That has got to help towards herd immunity.

 

[JoeWras]

I'm hoping the concern about vaccinated people still spreading like super-spreaders is a bit overblown. I like sengsational's thoughts. Maybe spread only a tiny bit for a little while.

You see, if the vaccinated are out and about with their "superpower," yet still spreading like Typhoid Mary, then those of us at the end of the vaccination queues are Sitting Ducks. We're going to have to hunker down deeper than ever.

 

[NanoSour]

I'll be the first to admit that I know nothing, but my understanding is that coronavirus immunity, whether natural or through a vaccine, is relatively short lived. On the order of 2-6 months and most certainly varies person to person. This is why you can sometimes have several colds in one season. I know I have.

Given this, I'm not that excited about the recent reports that only checked for immunity efficacy at 1 and 2 weeks post the 2nd vaccine dose. I'm very interested to know what the efficacy will be at 1, 2, 3...etc months.

Also, given that this could potentially be the first mRNA vaccine approved for human use, we are not at all sure about the long-term impacts of messing with the DNA blueprints of the human genome. Scary stuff from where I sit.

 

[Aerides]

I'll be the first to admit that I know nothing, but my understanding is that coronavirus immunity, whether natural or through a vaccine, is relatively short lived. On the order of 2-6 months and most certainly varies person to person.

While the definitive answer is still unknown, recent reports suggest immunity may last a lot longer, based on antibodies staying present in patients at decent levels, months after recovery. NYT published a piece on 11/17.

 

[Rustic23]

If you can get a 95% effective vaccine and you are in the highest risk group, what are the chances tht you will go without a mask among Covid-ineffected people?

I depends on weather you use suspenders with your belt

 

[gerntz]

Also, given that this could potentially be the first mRNA vaccine approved for human use, we are not at all sure about the long-term impacts of messing with the DNA blueprints of the human genome. Scary stuff from where I sit.

OK, then give it just to those of us past the reproductive stage in life.

 

[Aerides]

If you can get a 95% effective vaccine and you are in the highest risk group, what are the chances tht you will go without a mask among Covid-ineffected people?

in an at-risk group, I'd recommend maintaining common-sense protocols until both are true:

The community/stores no longer requires/recommends masks
and
The R0 rate in the areas I'm going to be are super low (like way sub sub 1%)

Even then, with things like flying? I might keep up a mask for a long time. I got a cold or something, way more than 25% of the times I flew in the past.

 

[Christine]

Over in the UK Dr John Campbell explains how the Oxford vaccine works. The AstraZeneca one. The gist of it is that it will take several weeks from getting the shots until you get the full immune effect. But then it's 90% efficiency for this one too.



So after the first of two shots there is an approximately two months of waiting before life can go back to more normal. Is this slow build of immunity how the other two current vaccines work?

 

[harllee]

If you can get a 95% effective vaccine and you are in the highest risk group, what are the chances tht you will go without a mask among Covid-ineffected people?

As a high risk person I think my life has been altered regarding wearing masks. I have not had so much as a sniffle since last February when I started wearing masks. I can see myself wearing masks from now on when I am in crowds. Even after the Covid vaccine a mask will help protect me from the diseases like the common cold and flu. I don't mind wearing a mask at all--I have gotten use to it.

 

[Aerides]

Over in the UK Dr John Campbell explains how the Oxford vaccine works. The AstraZeneca one. The gist of it is that it will take several weeks from getting the shots until you get the full immune effect. But then it's 90% efficiency for this one too.

So after the first of two shots there is an approximately two months of waiting before life can go back to more normal. Is this slow build of immunity how the other two current vaccines work?

The flu vaccine works that way, about 2 weeks to build up antibodies. I would expect all of them to have some delay guidance, even the one-and-done shots.

 

[sengsational]

Weird results with the AstraZeneca with 1/2 dose / full dose. So far, I haven't heard why it was weird.

The results show 90% effectiveness, but only if the first dose was half of the normal dose. This part of the trial was in Brazil, so maybe they wanted to make "n" large, but didn't have enough vaccine? Somehow they gave 1/2 dose on the first shot. Then, a month later, they gave a second dose, this time full dose. It turns out that the Brazilians in the study did better than the other group in the UK, where it was two full doses. The p values were great (1 in 10,000), so it's not like this could have happened randomly. I wonder if the Brazilian population is different. I'm sure they are genetically different than the UK group (UK would probably tend to be more genetically diverse). Or it could be the strain in Brazil was different. It will be interesting to watch this play out.

 

[Amethyst]

Based on what I've read, they made an error with about 2,800 of the first doses - accidentally cutting them in half.

People make mistakes, but this seems a bit out of line for something as important as sticking needles full of vaccines into people.

Weird results with the AstraZeneca with 1/2 dose / full dose. So far, I haven't heard why it was weird.

The results show 90% effectiveness, but only if the first dose was half of the normal dose. This part of the trial was in Brazil, so maybe they wanted to make "n" large, but didn't have enough vaccine? Somehow they gave 1/2 dose on the first shot. Then, a month later, they gave a second dose, this time full dose. It turns out that the Brazilians in the study did better than the other group in the UK, where it was two full doses. The p values were great (1 in 10,000), so it's not like this could have happened randomly. I wonder if the Brazilian population is different. I'm sure they are genetically different than the UK group (UK would probably tend to be more genetically diverse). Or it could be the strain in Brazil was different. It will be interesting to watch this play out.

 

[explanade]

Key issues still to be determined are vulnerability to infections and whether the vaccinated can still spread the infection to others.

Do vaccines prevent disease or infection?

The type of efficacy that's been reported for these trials is protective efficacy against disease — in other words, how well the vaccine protects people from getting sick.

Whether or not these vaccines prevent people from getting infected in the first place is a separate question, and not one researchers can answer just yet.

Dr Labzin said it's possible there were people in the trials who received the vaccine, got infected with COVID-19, but didn't develop any symptoms.

They wouldn't have been identified, nor included in interim analyses, because researchers were specifically looking at whether the vaccine stopped or reduced the severity of COVID-19 symptoms — not whether the vaccine prevented the virus from entering a person's body.

"That's going to take a lot more analysis of the data and a lot more time," Dr Labzin said.

Both Pfizer and Moderna have indicated that their vaccines appear to prevent both mild and severe forms of COVID-19.

Can a vaccinated person still spread the virus?

One of the reasons it's important to find out whether coronavirus vaccines prevent infection (and not just disease) is because it will help determine whether or not vaccinated people can still transmit the virus — even if they're not sick.

"Ultimately, the best kind of vaccines are the ones that stop infection from being able to establish a foothold at all," Dr Labzin said, "so if we get exposed and we're vaccinated, we're not going to accidentally transmit that onto someone who's not vaccinated."

Dr Quinn said the mechanism used in the experimental vaccines to prevent disease "should also hopefully be reducing viral load in people" and therefore reduce their likelihood of shedding the virus and infecting someone else.

"But it's really hard to say at this point whether either of these vaccines are impacting infection rates … and how they're impacting the likelihood of someone who is vaccinated [passing] the infection onto other people."

That all depends on viral load and how much viral replication is happening, Dr Quinn said.

'They do have ways of looking at that, but that kind of information won't come until later."

Dr Quinn said there are examples of other vaccines where people can be vaccinated, but still spread a disease to others.

https://www.abc.net.au/news/health/...accines-prevent-infection-or-disease/12905654

 

[Mark1]

Weird results with the AstraZeneca with 1/2 dose / full dose. So far, I haven't heard why it was weird.

Yes, very wield results if you listen to the U-tube above. It makes me realize that mixing vendor products is a going to be a huge unknown. What happens if you start down a vendor path and then can't get the second shot (much like we saw with Shingles shots)? How long do you wait before you switch to another vendor product? Hopefully we will get some guidance on this issue as we move forward.

 

[kcowan]

in an at-risk group, I'd recommend maintaining common-sense protocols until both are true:

The community/stores no longer requires/recommends masks
and
The R0 rate in the areas I'm going to be are super low (like way sub sub 1%)

Even then, with things like flying? I might keep up a mask for a long time. I got a cold or something, way more than 25% of the times I flew in the past.

Yes i think I will continue to wear a mask on public transit and other crowds.It just takes a little discipline and could reap outsized rewards.

 

[Popeye]

Yes, very wield results if you listen to the U-tube above. It makes me realize that mixing vendor products is a going to be a huge unknown. What happens if you start down a vendor path and then can't get the second shot (much like we saw with Shingles shots)? How long do you wait before you switch to another vendor product? Hopefully we will get some guidance on this issue as we move forward.

Somehow we need to avoid that kind of mess. Getting the first dose should reserve you the second dose at a specific time/place.