COVID-19 Vaccine Talk, 2nd Dose

[oldschoolcalgary]

Originally Posted by Weitz

What’s up with the booking site? Saying I’m ineligible to book my third dose of Pfizer? Anyone have this issue?

yes... that also happened to me this morning.

I did book a shot 2 weeks ago, but the pharmacist noted that I was didn't have 5 months between and that I should book in 2 weeks.

so, I tried and couldn't... I am assuming this is just a glitch, as I had no issue booking the booster previously.

outside of my arm being sore and being a little more tired, I haven't had any adverse reactions to Pfizer...

[calf]

Originally Posted by Weitz

What’s up with the booking site? Saying I’m ineligible to book my third dose of Pfizer? Anyone have this issue?

Are you using a mobile site or desktop? I had the same issue when trying to re-book my son's 2nd dose appointment. The mobile site kept on giving the error, but on a desktop, there was a drop-down saying "select 1st, 2nd or Booster", and then by clicking 2nd, it worked fine.

[oldschoolcalgary]

can't speak for Weitz, but I was using the desktop...I'm sure it's just temporary

[Weitz]

Using desktop here too..maybe I’ll just choose second.

[calgarygeologist]

Question for anyone that knows about vaccines either by education or just by significant research recently because I don't feel as though I understand things very well. Does it seems like the effectiveness provided by mRNA vaccine (ie the covid vaccine) is disappointing? There are reports out today that apparently a third dose, booster, loses effectiveness as early as 4 months and this is on the heels of the second dose losing effectiveness after 6 months. Maybe this is just because of the Omicron variant and if we were still dealing with earlier variants the effectiveness would not drop off as quickly but I really don't know. If we had a "conventional" live vaccine instead of mRNA would we be in a better position hypothetically? The biggest benefit of mRNA vaccine is the increased speed of development and production but are we sacrificing protection for that speed?

[opendoor]

Originally Posted by calgarygeologist

Question for anyone that knows about vaccines either by education or just by significant research recently because I don't feel as though I understand things very well. Does it seems like the effectiveness provided by mRNA vaccine (ie the covid vaccine) is disappointing? There are reports out today that apparently a third dose, booster, loses effectiveness as early as 4 months and this is on the heels of the second dose losing effectiveness after 6 months. Maybe this is just because of the Omicron variant and if we were still dealing with earlier variants the effectiveness would not drop off as quickly but I really don't know.

Coronavirus antibodies wane; there's not much we can do about that. However, the reason the effectiveness is waning so quickly is entirely because of Omicron. Antibodies to prior variants can neutralize Omicron, but it's more through brute force so you need a lot of them. So where a 3rd dose could conceivably give very good protection against Alpha or Delta for perhaps a year or so, it's only a few months for Omicron because the antibodies are far less suited to neutralizing it. That is to say, after 4 months you might have an antibody response to Delta that's 10x what's needed for neutralization, but not enough of a response against Omicron to neutralize it.

If we had a "conventional" live vaccine instead of mRNA would we be in a better position hypothetically? The biggest benefit of mRNA vaccine is the increased speed of development and production but are we sacrificing protection for that speed?

Likely not. Inactivated COVID vaccines exist and they're generally not very good at all compared to the better alternatives (though they are much better tolerated). There aren't any live attenuated virus vaccines in use yet, but there is an intranasal one being studied, though there isn't any reason to think it would be inherently more effective. Antibody responses to the non-spike parts of the virus are either more or less useless at neutralization (in the case of the N-protein) and/or only visible to the immune system after infection (the envelope and membrane proteins), so they're not going to help too much by being in a vaccine. There's a reason the spike protein was chosen by virtually every vaccine maker as the target.

And it's not like mRNA are the only ones in use. There are also viral vector (AZ and J&J) as well as recombinant protein (Novavax) vaccines. That's not to say there's no improving on the current vaccines; 2nd generation ones might provide longer-lasting or better protection that's more resistant to variants; or they might have far fewer adverse reactions, but there are going to limits to what's capable with a coronavirus vaccine.

[photon]

When the mRNA vaccines first came out I think everyone was pretty shocked at how amazingly good they were against the strain they were based off of.

Many Greek alphabet letters later...

[bizaro86]

Originally Posted by opendoor

There aren't any live attenuated virus vaccines in use yet, but there is an intranasal one being studied, though there isn't any reason to think it would be inherently more effective.

Be interesting to see where they try and get test subjects for that. Vaccine uptake is already very high, and the folks who aren't vaccinated aren't likely to sign up for a vaccine trial at this point, imo.

Could you trial a new vaccine on people who are already vaccinated and compare that to a control group of other already vaccinated people?

[MissTeeks]

Health Canada approved use of Novavax:

https://www.ctvnews.ca/health/corona...nada-1.5785244

Health Canada has authorized the use of the Novavax COVID-19 vaccinefor adults in Canada.

The two-dose Novavax Nuvaxovid vaccine showed 90 per cent effectiveness in protecting clinical trial participants from symptomatic COVID-19, and 100 per cent effectiveness in preventing severe disease, according to a press release from the agency.

[opendoor]

I'm sure all the antivaxxers who claimed they were waiting for Novavax will be beating down the doors of vaccination clinics. Or maybe now they'll hold out for Medicago.

[opendoor]

Originally Posted by bizaro86

Be interesting to see where they try and get test subjects for that. Vaccine uptake is already very high, and the folks who aren't vaccinated aren't likely to sign up for a vaccine trial at this point, imo.

Could you trial a new vaccine on people who are already vaccinated and compare that to a control group of other already vaccinated people?

Well some of the trials started a while ago when there were more immunologically naive people. And at this point, they're moving away from worrying about that since barely anyone is going to fit that category, so why bother trying to use them as any kind of reference point?

[GoinAllTheWay]

Originally Posted by opendoor

Or maybe now they'll hold out for Medicago.

What are they up to these days? I remember reading about the plant based vaccine and it seemed promising. Haven't heard anything from the in ages.

[opendoor]

Originally Posted by GoinAllTheWay

What are they up to these days? I remember reading about the plant based vaccine and it seemed promising. Haven't heard anything from the in ages.

They released phase 3 data a couple of months ago which was pretty good (~75% against Delta), and are currently under review by Health Canada. Not sure if they've produced much of anything in terms of doses though (that's also Novavax's issue). The rate of adverse events was fairly high though; nothing serious in the trial, but generally the COVID vaccines that are less well tolerated in trials tend to also have higher rates of more serious adverse events in the real world. So it's not really clear where it fits in with the current vaccine landscape.

Probably the only thing that's going to really supplant mRNA vaccines in industrialized countries in the near term will be if Novavax can be shown to have fewer adverse events. If it can maintain mRNA level efficacy while eliminating myocarditis risk, it could be the best option for further doses. But who knows what will happen in the real world. 1 in 50-100K side effects like myocarditis won't show up in trials where only 15K people are vaccinated.

[Fuzz]

Novavax Inc NVAX.O said on Monday that an extended analysis of a late-stage study conducted in the United Kingdom showed that its COVID-19 vaccine provided long-term protection against the coronavirus.

The protein-based vaccine, NVX-CoV2373, continued to provide protection and maintained overall efficacy of 82.7% over a six-month period, the company said.

Additionally, vaccine efficacy of 82.5% was maintained against both symptomatic and asymptomatic infection, while vaccine efficacy against severe disease was 100%.

The analysis was conducted between November 2020 and May 2021 before the Delta and Omicron variants became dominant.

https://www.ctvnews.ca/health/corona...rial-1.5799676

[bizaro86]

One of my wife's close friends called EMS for her elementary age son having chest pain. Diagnosed as arrhythmia, 1 day after second Pfizer dose, with no previous medical history. Medical staff say timing is a coincidence and it won't be reported as a potential vaccine reaction.

My plan of getting our kids second doses took a huge hit - my wife and I are both vaccinated but she was already hesitant about getting it for the kids. They do have their first doses already.

[#-3]

Originally Posted by bizaro86

One of my wife's close friends called EMS for her elementary age son having chest pain. Diagnosed as arrhythmia, 1 day after second Pfizer dose, with no previous medical history. Medical staff say timing is a coincidence and it won't be reported as a potential vaccine reaction.

My plan of getting our kids second doses took a huge hit - my wife and I are both vaccinated but she was already hesitant about getting it for the kids. They do have their first doses already.

Consider if you will that like half a billion kids are going to get vaccinated, and bad health outcomes probably happen to millions of children around the world daily. Somewhere in there there will be some coincidental overlap.

[ikaris]

Originally Posted by bizaro86

One of my wife's close friends called EMS for her elementary age son having chest pain. Diagnosed as arrhythmia, 1 day after second Pfizer dose, with no previous medical history. Medical staff say timing is a coincidence and it won't be reported as a potential vaccine reaction.

Imagine how often this occurs. Don’t worry, it’s just a coincidence.

[bizaro86]

Originally Posted by #-3

Consider if you will that like half a billion kids are going to get vaccinated, and bad health outcomes probably happen to millions of children around the world daily. Somewhere in there there will be some coincidental overlap.

For sure, it absolutely could be a coincidence. Bad stuff happens all the time and some of it will happen after people get a vaccine. My wife's friend is a chemist and my wife is a science teacher, neither of them are anti-science at all.

But the correct time for that to get declared a coincidence is not with the front line health care workers saying its just one of those things that happen. Worth noting they did not find a specific cause.

It's impossible to do good science without good data. Potential adverse reactions should be reported and analyzed. Then researchers can compare the incidence of specific adverse events post vaccine to those that you would expect to occur in the same timeframe and analyze for statistical significance.

My strong preference is to trust the medical establishment, but they did the wrong thing in this instance.

[opendoor]

Passive reporting systems are pretty much useless for determining rates of adverse events for exactly that reason; they rely on a frontline healthcare worker to decide whether it's related, which often is basically a guess. However, other places have more robust systems where they automatically cross reference these things against vaccination status and when the person was vaccinated, and they're not finding huge increases in adverse events either, so I think the idea that there is this huge undercount of reactions isn't supported by the evidence. They certainly happen, but they're relatively rare.

Obviously the risk/benefit of vaccination changes drastically depending on the age, so the benefit gets less clear as you get younger. Still, there is a pretty clear benefit for all ages. In the last 120 days, about 1 in 2.5K 5-11 year olds has been hospitalized with COVID in Alberta (that's in terms of population, not infections), whereas there hasn't been a single hospitalized case among fully vaccinated in that age group. Assuming a ~30% attack rate in that period, that would suggest that not vaccinating a 5-11 year old is likely risking a 1 in 750 chance of hospitalization or a 1 in 4K chance of ICU admission from COVID in order to protect against a 1 in ~10-20K chance of myocarditis from the vaccine. For an immunologically naive kid that age, I think the math is pretty clear; you're about 10-20x more likely to have a severe case of COVID if you're unvaccinated than you are to have a serious adverse reaction after being vaccinated.

[ikaris]

Originally Posted by opendoor

Obviously the risk/benefit of vaccination changes drastically depending on the age, so the benefit gets less clear as you get younger. Still, there is a pretty clear benefit for all ages. In the last 120 days, about 1 in 2.5K 5-11 year olds has been hospitalized with COVID in Alberta (that's in terms of population, not infections), whereas there hasn't been a single hospitalized case among fully vaccinated in that age group. Assuming a ~30% attack rate in that period, that would suggest that not vaccinating a 5-11 year old is likely risking a 1 in 750 chance of hospitalization or a 1 in 4K chance of ICU admission from COVID in order to protect against a 1 in ~10-20K chance of myocarditis from the vaccine. For an immunologically naive kid that age, I think the math is pretty clear; you're about 10-20x more likely to have a severe case of COVID if you're unvaccinated than you are to have a serious adverse reaction after being vaccinated.

The issue is that you’re calculating the odds assuming all things equal for all children within the age group. This does not look at the particular risk when considering a healthy child versus someone who is immunocompromised or has some other comorbidity. Unfortunately this data is not readily available considering severe outcomes from COVID stratified over age groups (if it is, I would be interested in seeing the comparative risk.)