Efficacy of vaccines - Printable Version

Efficacy of vaccines - Printable Version

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Efficacy of vaccines - Mick - 09-26-2020

The Chinese approach to vaccines sounds perfectly safe...
https://worldnewsera.com/news/business-news/china-gives-unproven-covid-19-vaccines-to-thousands-with-risks-unknown/

Could be worse. Could be the mystery illnesses in AstraZeneca's trials:
https://www.cnn.com/2020/09/25/health/astrazeneca-covid-19-vaccine-trial-questions-fda/index.html

RE: Efficacy of vaccines - BostonCard - 09-26-2020

Quote:...crucial questions remain about neurological illnesses suffered by study participants who received injections of the experimental vaccine.

It says “neurological illnesses”, plural. This is concerning.

BC

Vaccines - BostonCard - 09-28-2020

This is a super long (>100 tweet) Twitter thread, but very much worth reading if you want to understand the state of COVID-19 vaccine development. Skip to the end if you want a prediction of which vaccine is likely best.

[tweet]https://twitter.com/florian_krammer/status/1310372301314101250?s=21[/tweet]

For those who would rather get your vaccine information from peer reviewed journals than Twitter, Kramer wrote a review on the subject in Nature. Link is in the thread.

BC

RE: Vaccines - OutsiderFan - 09-29-2020

It seems we can have a vaccine with low efficacy and distribute widely in the near term. Or, we can have a vaccine with high efficacy that will take a long time to distribute widely.

For those looking to have political victories more than they care about actually addressing the problem in a meaningful way, the choice will be obvious. It sets up like the scene in Jaws where the Amity Mayor declares victory after a Tiger Shark was caught, when the “man eating” Great White Shark was the problem and still at large, to justify opening the beaches on July 4. Then the kid is killed and his mother slaps the Mayor after she learns the Mayor knew the real problem shark was not addressed before the beaches were opened.

Is a vaccine that is 50% effective worth distributing, when if we wait a few months more, one with 80% efficacy is widely available? That extra 30% is the difference between on way to effective virus elimination and it still being a problem even after widely distributed vaccine is taken by masses.

For me, it would be very bad to go with the lower efficacy option that can be distributed right away, because not only will it not be as effective as necessary, a vaccine that doesn’t work will make it more likely people won’t get the next higher efficacy one, and may also lead to more people questioning other vaccines across the board, when the reality is they shouldn’t trust political figures.

Would the WHO or FDA endorse a 50% effective vaccine today, when an 80% effective one is a few months away? I honestly don’t know. This in and of itself is pretty f*cking scary.

RE: Vaccines - BostonCard - 09-29-2020

First, here is the the thread reader link (the entire 100+ tweets in the thread in a single place):

https://threadreaderapp.com/thread/1310372301314101250.html

I don't draw the same conclusion as you do. The Pfizer vaccine is the one that is probably most likely to give an early readout (the Pfizer CEO has talked about preliminary data being ready by the end of October). It is also one of the two, that the thread author would take himself (based on the data to date). If you read the Nature review, he notes:

Quote:It is highly likely that the AstraZeneca, Moderna and Pfizer vaccine candidates, which are along the furthest in the US and Europe, all show sufficient efficacy and will be licensed if sufficiently safe. However, it may also be that these vaccines will later on be replaced by vaccines that show similar efficacy but have reac- togenicity profiles that are more tolerable.

So, you are looking at vaccines that he believes (based on the data that has been generated to date, and with all the caveats that come with that), will have "sufficient efficacy", the Pfizer one (as well as the ones from AZ and Moderna) may well clear that bar. However, he believes that they will be more reactogenic than subsequent vaccines and thus cause more interferon-related side effects (fevers, fatigue, headache, esp), but he notes that "These site effects are unpleasant but usually transient and not too concerning (they might be problematic in kids, more about that later)." Subsequent vaccines may cause fewer side effects, but may or may not be better.

The other thing about the Pfizer (and Moderna) vaccines are mRNA vaccines, and thus will need a cold chain until they are administered. This will make them challenging to distribute, but that doesn't mean he believes they will be less effective.

Based on his assessment, however, the protein based vaccines will have the best combination of low reactogenicity and high immunogenicity. That would mean the Novavax vaccine amongst the vaccines in Phase 3.

None of this means that someone (especially a high-risk individual) couldn't take an early approved vaccine, and then take a more effective vaccine if one were to come out later.

BC

RE: Efficacy of vaccines - Hurlburt88 - 10-05-2020

https://www.msn.com/en-us/money/companies/report-moderna-and-pfizer-vaccine-trial-participants-report-serious-side-effects/ar-BB19IGK0?li=BBnbfcL

a bit of vaccine news. I believe the Oxford/AstraZeneca vaccine remains on FDA hold in the US while proceeding in the UK and other countries. Other news stories obviously eclipsing that one

RE: Efficacy of vaccines - BostonCard - 10-05-2020

The Moderna severe adverse events were predictable based on the Phase 1 data. If the drugs work, it is probably acceptable for 1 patient in 5,000 to have severe symptoms if they resolve within a day.

BC

RE: Efficacy of vaccines - BostonCard - 10-05-2020

Here's a relevant (free) webinar:

https://pharm.ucsf.edu/acdrs/webinar

Quote:The Challenges of Vaccine Development (Without and With a Pandemic)

Speaker: Emilio A. Emini, PhD, FCCP, FAAM, Director, TB and HIV Program, Bill & Melinda Gates Foundation

The development of novel vaccines designed to prevent disease caused by infectious agents is a highly complex process. It is characterized by a large set of parallel development risks ranging from uncertainty over the nature of the desired immune response to uncertainty over the ability to fully control at-scale manufacturing. In “normal” times, the investment risks (financial and opportunity) are mitigated by addressing the challenges in a roughly linear fashion to de-risk the uncertainties and increase the relative probability of success over time. As such, it is not unusual for a novel vaccine development program to take up to ten years and occasionally more. The development process requires a high level of control, continuous quantitative characterization, and rigorous regulatory supervision. The presentation will discuss the “nature” of prophylactic vaccines and how this nature underlies specific development challenges and uncertainties. The presentation will also discuss the unique circumstances surrounding the development of COVID vaccines, and specifically the extraordinary challenges associated with the goal of developing and scaling-up an effective vaccine in less than one year(!). The discussion will conclude with lessons learned that will (hopefully) help in the vaccine response to the next pandemic.

__________________________________________________________
October 26, 2020
noon - 1:00 pm eastern / 9:00 - 10:00 am pacific
__________________________________________________________

There is no registration fee, but advanced registration is required for planning purposes.

Registration: https://ucsf.zoom.us/webinar/register/WN_QECz4iWcRg6jrxxljDRFUA

Please pass along this announcement to any of your colleagues who may be interested in attending.

Further information on the ACDRS Webinar Series can be found at https://pharm.ucsf.edu/acdrs/webinar .

RE: Efficacy of vaccines - fullmetal - 10-05-2020

I'm not looking forward to a low efficacy vaccine even if it is widely distributable sooner specifically because I think you're going to see a lot of folks relax public health measures as soon as they hear that a vaccine of any kind is available. Of course, the demographic that's itching to ditch the masks/social distancing measures probably also overlaps highly with the demographic that rejects vaccines...

RE: Efficacy of vaccines - Goose - 10-05-2020

(10-05-2020, 01:04 PM)fullmetal Wrote: Of course, the demographic that's itching to ditch the masks/social distancing measures probably also overlaps highly with the demographic that rejects vaccines...

I think you are trivially correct because essentially EVERYBODY is itching to ditch masks/social distancing. The real question is how many people will equate the availability of a vaccine to safety in ditching these precautions. Even if we have a very good vaccine it is going to take a while for the population as a whole to get it. I think it is virtually certain that far too many people are going to assume that all is now safe way way too early.

RE: Efficacy of vaccines - BostonCard - 10-05-2020

Supposedly the White House is blocking the CDC's COVID vaccine criteria.

https://thehill.com/homenews/administration/519742-white-house-blocks-new-fda-coronavirus-guidelines-that-may-have

Quote:The FDA first submitted the proposal for new guidelines in late September, but they were immediately rebuffed by President Trump and top officials who worried it would delay the release of a vaccine as Trump's "Operation Warp Speed" has sought to quickly move one through the approval process.

I wish this were not around an election so that any consideration of granting an EUA wasn't tied to an arbitrary date on the calendar.

BC

RE: Efficacy of vaccines - BostonCard - 10-06-2020

The FDA released its vaccine EUA guidance:

https://www.fda.gov/media/142723/download

BC

RE: Efficacy of vaccines - BostonCard - 10-12-2020

Now Johnson & Johnson pauses its vaccine trial as it investigates an "unexplained illness"

https://www.statnews.com/2020/10/12/johnson-johnson-covid-19-vaccine-study-paused-due-to-unexplained-illness-in-participant/

Hope it winds up being unrelated to the vaccine (ideally having occurred in a placebo patient).

BC

RE: Efficacy of vaccines - magnus - 10-26-2020

The AstraZeneca vaccine has induced an immunological response from older patients.

https://www.reuters.com/article/reutersComService_2_MOLT/idUSKBN27B0IV

RE: Efficacy of vaccines - BostonCard - 10-26-2020

https://www.wsj.com/articles/covid-19-vaccine-trial-from-astrazeneca-oxford-can-resume-in-u-s-11603476923

The FDA has lifted its clinical hold on trials from Astra Zeneca and Johnson and Johnson. In the AZ trial:

Quote:The AstraZeneca decision, which was first reported by The Wall Street Journal, came after the FDA didn’t find the vaccine was responsible for the two cases, though the agency couldn’t rule out a link either, a person familiar with the matter said.

The agency plans to require researchers to inform study subjects of the cases and monitor them for any related neurological events, such as numbness, the person said.

It is very hard to prove or disprove causality in single events. It is concerning that there were two neurological cases, though they must have been dissimilar enough for the agency not to have found a pattern (one sounds like a patient who developed MS, the other remains a mystery).

Based on the article, it sounds like the J&J was on a voluntary hold (not by the FDA), and the company was comfortable enough to resume.

BC

RE: Efficacy of vaccines - dabigv13 - 10-28-2020

Pfizer has been talking publicly for months now about late October, but apparently they have not been able to demonstrate efficacy at this point. Seems they haven't gotten enough infections to know yet.

https://www.politico.com/news/2020/10/27/vaccine-race-meets-harsh-reality-432964

RE: Efficacy of vaccines - BostonCard - 10-28-2020

(10-28-2020, 09:10 AM)dabigv13 Wrote: Pfizer has been talking publicly for months now about late October, but apparently they have not been able to demonstrate efficacy at this point. Seems they haven't gotten enough infections to know yet.

https://www.politico.com/news/2020/10/27/vaccine-race-meets-harsh-reality-432964

Ironically that could be good news, if the reason they haven't had enough events is that the vaccine is working and only patients in the placebo arm are accruing events.

BC

RE: Efficacy of vaccines - dabigv13 - 10-28-2020

Right. Still could be a great, average, or poor vaccine from what we know publicly thus far. In any case, the Pfizer CEO probably shouldn't have been speculating like he was for so long about late October when he knew it was only an interim endpoint, and with the political background that this vaccine is being developed in.