Posted on 09/27/2020 8:35:15 PM PDT by SeekAndFind
With Covid-19 vaccines currently in the final phase of the study, you’ve probably been wondering how the FDA will decide if a vaccine is safe and effective.
Based on the status of the Phase 3 trials currently underway, it is unlikely that the results of these trials will be available before November. But it is likely that not just one but several of the competing Covid-19 vaccines will be shown to be safe and effective by the end of 2020.
I am a scientist and infectious diseases specialist at the University of Virginia, where I care for patients with Covid-19 and conduct research on the pandemic. I am also a member of the World Health Organization Expert Group on Covid-19 Vaccine Prioritization.
What is the status of Covid-19 vaccines in human clinical trials?
Phase 3 studies are underway for the Moderna and BioNTech/Pfizer vaccines and the Oxford/AstraZeneca viral vector vaccine.
Each of these vaccines uses the SARS-CoV-2 spike glycoprotein, which the virus uses to infect cells, to trigger the immune system to generate protective antibodies and cellular immune response to the virus. Protective antibodies act by preventing the spike glycoprotein from attaching the virus to human cells, thereby neutralizing the SARS-CoV-2 virus that causes COVID-19.
In the case of Moderna’s nucleic acid vaccine, the messenger RNA encoding the spike glycoprotein is encased in a fat droplet – called a liposome – to protect the mRNA from degradation and enable it to enter cells. Once these instructions are inside the cells, the mRNA is read by the human cell machinery and made into many spike proteins so that the immune system can respond and begin producing antibodies against this coronavirus.
The Oxford/AstraZeneca uses a different strategy to activate an immune response. Here an adenovirus found in chimpanzees shuttles the instructions for manufacturing the spike glycoprotein into cells.
Phase 1 and 2 studies by pharmaceutical companies Janssen and Merck also use viral vectors similar to the Oxford/AstraZeneca vaccine, while vaccines by Novavax and GSK-Sanofi use the actual spike protein itself.
Animal tests show the vaccines provide protection from coronavirus infection
Studies in animal models of COVID-19 provide convincing evidence that vaccination with the spike glycoprotein will protect from COVID-19. Experiments have shown that when the immune system is shown the spike protein – which alone cannot trigger disease – the immune system will generate an antibody response that protects from infection with SARS-CoV-2.
In studies in hamsters an adenovirus viral vector – the approach used by Oxford/AstraZeneca, for example – was used to immunize with the Spike glycoprotein. When the hamsters were infected with SARS-CoV-2 they were protected from pneumonia, weight loss, and death.
In nonhuman primates, DNA vaccines – which deliver the gene for the spike glycoprotein – reduced the amount of virus in the lungs. Animals that produced antibodies that prevented virus attachment to human cells were most likely to be protected.
History of vaccines: Smallpox to SARS-CoV-2.
What have the early Phase 1 and 2 studies in humans shown?
Overall, vaccination has triggered a more potent neutralizing antibody response than even that seen in patients recovering from Covid-19.
This has also been the case for Moderna’s vaccine currently in Phase 3 trials and for vaccines from CanSino Biologics and Oxford/ AstraZeneca.
What side effects have been observed?
Physicians have recorded mild to moderate reactions when the subjects were observed up to 28 days after vaccination. These side effects included mild pain, warmth, and tenderness at the site of injection, and fever, fatigue, joint, and muscle pain.
But Phase 1 and 2 studies are by small by design, with just hundreds of participants. So these trials will not be large enough to detect uncommon or rare side effects.
The emphasis on safety as the primary goal was recently demonstrated in the Phase 3 Oxford/AstraZeneca vaccine trial where one vaccinated individual developed inflammation of the spinal cord. It isn’t clear whether the vaccine caused this reaction – it might be a new case of multiple sclerosis unrelated to the vaccine – but the Phase 3 trial was halted in the U.S. until more is known.
How is the FDA ensuring that a vaccine will be safe yet quickly produced?
The FDA has issued guidance for industry on the steps required for developing and ultimately licensing vaccines to prevent Covid-19 – these are the same rigorous safety standards required for all vaccines.
There are, however, ways to speed the process of approval that are centered on “platform technology.” What this means is that if a vaccine is using an approach such as an adenovirus that has previously been shown to be safe, it may be possible for a company to use previously collected data on toxicity and pharmacokinetics to fast-track clinical trial approval.
While speed and safety may appear conflicting goals, it is also encouraging to note that the rival vaccine manufacturers have jointly pledged not to bow to any political pressures to rush vaccine approval but to maintain the most rigorous safety standards.
How to develop a vaccine, quickly.
How protective does a vaccine need be to receive FDA approval?
The FDA has set the bar for the primary endpoint of a Phase 3 trial of 50% protection for approval of a Covid-19 vaccine.
Protection is defined as protection from symptomatic Covid-19 infection, defined as laboratory-confirmed SARS-CoV-2 infection plus symptoms such as fever or chills, cough, shortness of breath, fatigue, muscle aches, loss of taste or smell, congestion or runny nose, diarrhea, nausea or vomiting.
This means that an effective vaccine is considered one that will reduce the number of infections in vaccine recipients by half. This is the minimal protection that is anticipated to be clinically useful. That is, in part, because lower levels of efficacy could paradoxically increase Covid-19 infections if it leads vaccinated people to decrease mask-wearing or social distancing because they think they are completely protected.
Since a vaccine might be more effective at preventing severe Covid-19, the FDA instructs that protection from severe Covid-19 should be a secondary endpoint.
How many people have to be vaccinated to know if a vaccine works in Phase 3?
The current Phase 3 trials are enrolling 30,000-40,000 subjects. Most of these participants will receive the vaccine and some a placebo.
When, exactly, the results of Phase 3 studies will be released depends in large part on the rate of infection in the placebo recipients. The way that these vaccine studies work is that they test if naturally acquired new coronavirus infections are lower in the group that received the vaccine compared with the group receiving the placebo.
So while it is good news that Covid-19 infections have dropped recently in the U.S. from 70,000 to 40,000 cases per day, this drop in new infections may slow the vaccine studies.
Will the Emergency Use Authorization fast-track vaccine?
In an emergency such as we are faced with the Covid-19 pandemic, with approximately 700 new deaths and 40,000 new cases per day right now, the FDA is authorized to allow the use of unapproved products for the diagnosis, treatment, and prevention of disease. That includes a vaccine.
The standard approval process for vaccines can require more than one year of observation after vaccination. If the short-term safety is good and the vaccine works to prevent Covid-19, then the vaccine should be approved for use under an Emergency Use Authorization while it is still being studied.
Under Emergency Use Authorization, the FDA will continue to collect information from the companies producing the vaccines for benefit and harm, including surveillance for vaccine-associated enhanced respiratory disease or other potentially rare complications that might be observed in only one in a million.
What should we expect in terms of approvals?
I expect that the FDA will approve several vaccines by the end of 2020 under its Emergency Use Authorization authority so that vaccination can begin immediately, starting with high-risk groups including first responders, health care personnel, and the elderly and those with preexisting medical conditions.
This will be followed rapidly with the roll-out of vaccination to the population at large, while all of the time the FDA and vaccine manufacturers will continue to monitor for side effects and work to improve upon these first vaccines. This process is expected to take months.
It may not be life back to normal next year, but all signs point to a healthier 2021.
This article was originally published on The Conversation by William Petri at the University of Virginia. Read the original article here.
When will we know?
After the election. The whole thing is politicized to get Donald Trump out of office.
Many of the vaccines are using completely different approaches.
Can you take two or three vaccines and get extra protection?
Will these vaccines work like influenza vaccine and not fully prevent sickness, but make you get a much milder case?
I'll take Vaccine Failures for $200, Alex.
In April 1955, soon after mass polio vaccination began in the US, the Surgeon General began to receive reports of patients who contracted paralytic polio about a week after being vaccinated with Salk polio vaccine from Cutter pharmaceutical company, with the paralysis limited to the limb the vaccine was injected into. In response the Surgeon General pulled all polio vaccine made by Cutter Laboratories from the market, but not before 250 cases of paralytic illness had occurred. Wyeth polio vaccine was also reported to have paralyzed and killed several children. It was soon discovered that some lots of Salk polio vaccine made by Cutter and Wyeth had not been properly inactivated, allowing live poliovirus into more than 100,000 doses of vaccine. In May 1955, the National Institutes of Health and Public Health Services established a Technical Committee on Poliomyelitis Vaccine to test and review all polio vaccine lots and advise the Public Health Service as to which lots should be released for public use. These incidents reduced public confidence in polio vaccine leading to a drop in vaccination rates.
Process is virus pretty much is a joke and the average age of death is 82 I’d say the whole idea of a vaccine is absurd.
It is the next step in our enslavement by Bill Gates and Soros and the deep State and actually China. Ironic in that they started this
Here in Idaho, only NINE people under age 50 have died from it. That’s out of 1.6 million people. It is utterly ridiculous.
Your chances of dying from it are quite low if you are under age 70.
Fortunately, I’m under 70 for another ten months!
So, after reading all that comes the detail that the protection from the phase 3 tests of the vaccine is only 50% effective. Also sounds like the side effects are not much fun either. I will try my best to keep my routine of no Flu vaccines ever and no Flu either.
Exactly!
The vaccine industry is evil and wants compulsion
They already have media and government fooled
They don’t care about your health at all. Only profits. It’s big $$
Don’t be fooled. They DONT WORK and cause MUCH HARM
USE YOUR OWN METHODILOGIES TO COMBAT ILLNESS CAUSED BY VIRUSES AND BACTERIA
I USE SILVER. ITS VERY EFFECTIVE
I’m curious to see if this next “flu-season” won’t be a dandy. With everyone running around with masks on (many even when outside), and applying hand sanitizer every few minutes; it will be curious to see if our systems have weakened any.
From the article:
“...the FDA is authorized to allow the use of unapproved products for the diagnosis, treatment, and prevention of disease. That includes a vaccine. ...”
OK, FDA, how about OKing the use of HCQ + Azithromax/doxycycline + zinc to prevent and treat —early— the WuhanVirus??
“rival vaccine manufacturers have jointly pledged not to bow to any political pressures to rush vaccine approval”
Well hell, that settles it since we see so much integrity and objectivity from “experts” about everything from climate change to gender possibilities. Bring on the Orwellian vaccine.
The sad truth of it all is that this will all be over long before there’s a vaccine, but they will continue to present useless data as facts and ‘science’ to compel fear and compliance.
The fact of the matter is that “cases” are a dog whistle for the stupid.
Including here at FR.
You cannot get a case of CoVId from these vaccines. You ask that question an awful lot and the answer is still the same
As stated iin a previous thread you are being totally irresponsible
The Mayo Clinic
The Cleveland Clinic
Sloan Kettering
Harvard university school of medicine
All have extensively researched colloidal silver. All point out that silver is NOT an essential element and ingesting silver leads to HEAVY METAL POISONING and argryia. You previously stated this is conspiracy which would require all 8 Billion people in the world to be in on it to be true
Please stop practicing medicine and disseminating false and dangerous news. You are a menace.
I am a proponent of silver biotics (nano technology) and ingest it every day and have for many many years. In fact my entire family will not be without it. No blue tint to my skin or any of my siblings or their children or my friends. I love the gel and the lozenges, too. I gave the liquid to my father who had been given umpteen antibiotics for urinary tract infections with no relief. Every doctor’s visit was the same. . .more high powered antibiotics. I decided to give him the nano silver without telling the doctor. No more antibiotics needed. . . .the poor doctor kept thumbing through my dad’s records every routine visit. I silently laughed. The side affects of the antibiotics . . . .do the research. By the way, I squirt the gel on my dogs’ and cats’ food . . . my 12 year old beagle was almost mauled to death by another dog when he was 5 and I ditched the vet’s myriad of medicines and poured the liquid silver down the many tubes coming out of his body and lathered the stiches with gel . . . .people are amazed. . .absolutely NO scars. I’ll stick with the nano silver. Many companies are adding it to their products as well as bandages.
Me, too. I’m 77. Last flu bug I had was in 1970. No flu shots ever and no flu so far.
Hundreds of drugs have been approved and then recalled. Pleeeez...this is a race for the bank...
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