Thursday, October 29, 2020

We're Waiting?!?!

We're Waiting?!?!

"Experts predicting that there's only a 40 percent chance of a negative result, that to me actually sounds pretty optimistic."
"Even if  you have fifty percent protection, we still won't know whether these vaccines actually move the needle on the things we need to move the needle on."
"In medicine we license drugs and vaccines all the time, despite lingering uncertainties regarding impact and safety. [We can't wait for absolute certainty.]"
"The point is to make the best choices we can, given the evidence we have and to continue collecting evidence so that we can revise our choices if the data turn southward."
Jonathan Kimmelman, professor, director, Biomedical Ethics Unit, McGill University
"None of those trials [in Phase III studies] currently under way are designed to detect a reduction in any serious outcome such as hospital admissions, use of intensive care, or death. [Even mild infections could qualify as an] event."
"In Pfizer and Moderna's trials, for example, people with only a cough and a positive laboratory test would bring those trials one event closer to their completion."
Peter Doshi, associate editor BMJ (British Medical Journal)

"We just don't know what to expect. You start asking yourself very practical questions: If something doesn't work fifty percent [of the time], then do we really have something?"
"Maybe we do as an emergency response initially, but a fifty percent level we would have to imagine over time has to get better than that."
Bruce Clark, president, CEO, Medicago
A protester holds a placard that says 'Freedom No Lockdown Masks Tests Vaccine'.

Protesters call for an end to COVID-19-based restrictions in Sacramento, California.   Credit: Stanton Sharpe/SOPA Images/LightRocket/Getty

When might a COVID-19 vaccine be available? When no fewer than 28 experts with a quarter-century each experience in the field were asked their opinion by a team from McGill University, the guess was around June 2021 as a best-case scenario, but more likely to come on stream in the fall of next year. The experts were also of the opinion that a 3-in-10 chance existed that an issue of safety would eventuate after approval was given to the first vaccine, requiring a warning accompany the vaccine. More concerning, that a 4-in-10 chance would arise when the first large field study might project a negative result. As in back to Square One.

Professor Kimmelman of McGill University who was the senior author of the paper points out that fewer than five percent of non-pandemic flu vaccines tested in humans get approved; long odds making him puzzled at the state of confident optimism by public health officials such as U.S. coronavirus chief Dr.Anthony Fauci who states his belief with a decided certainty that an effective and safe vaccine will be available in the near future. A more realistic view, suggests Professor Kimmelman, is that an effective vaccine will evade the near future.

There is no certainty that vaccines reaching Phase III  trials representing the final stage before approval may be given, will deliver normalcy back to the world. Proposed FDA and international standards for such vaccines are being raised; how good would be good enough?, added to which looms the logistical challenge in distribution of a two-dose vaccine, and inoculating the world community, much less persuading the young and individuals at low risk of contracting COVID to be vaccinated to help achieve the longed-for herd immunity effect.

Over two hundred vaccines against the SARS-CoV-2 virus are currently in development, eleven of which are now in Phase III studies -- each one of which involves tens of thousands of volunteers. These are double-blind and placebo-controlled blue-ribbon trials where no one is privy to who is being inoculated with the real vaccine and who a placebo. Designed to conclude after 150 to 160 COVID infections are seen among the study volunteers, a data safety and monitoring board would be set to determine whether fewer infections took place among the vaccinated group.

 
 What is of utmost importance, cautions Dr. Kimmelman, is whether a vaccine will prevent deaths, ICU admissions or hospitalizations. Where the difficulty lies is that hospital admissions and deaths from COVID-19 are uncommon -- so that of necessity it would require a large population over a prolonged period of time to acquire sufficient death numbers to determine the existence of a difference between the vaccine and placebo group.

A minimum target of fifty percent efficacy for a COVID-19 vaccine has been set by the U.S. Food and Drug Administration, so that a vaccine would be expected to be fifty percent superior over a placebo at preventing disease. Moderna's vaccine in an early-stage study produced neutralizing antibodies in 45 healthy 18- to 55-year-olds receiving two vaccinations 28 days apart, as reported in the New England Journal of Medicine. Side effects such as fatigue chills, headache or muscle aches occurred in over half the participants.

While AstraZeneca's vaccine produced an immune response in both the young and old, Reuters reported. It was left uncertain how well an antibody response translates into how well any vaccine can prevent COVID, however. In the same token, even a vaccine that works only half the time, offers an opportunity at keeping the potency of the epidemic at a lower level, particularly should it prevent severe disease and deaths.

And then there is the possibility that vaccines with protection of 30 percent could also have emergency authorization under FDA and international standards, when the debate turns to 'how low can you go?'
"The problem you could create is the following: You push a low-efficacy vaccine out on the grounds it's better than nothing. Right now, you've got zero. Thirty percent protection? Better than zero."
"It's a really difficult question to know at what point do you say, 'it's good enough'."
"What's the ideal? The ideal is we totally understand how this virus works, we get a vaccine, we know that it will stop this pathogen from being able to infect humans and we know that it lasts for a specified time, for example, ten years, and then you get a second vaccine."
"You can't wait until you truly understand the scope of the problem because people are dying."
Francoise Baylis, philosopher, university research professor, Dalhousie University
A technician works in a lab at Sinovac Biotech where the company is producing their potential COVID-19 vaccine CoronaVac during a media tour on Sept. 24, 2020 in Beijing, China. Photo by Kevin Frayer/Getty Images

 

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