A handful of dozens of experimental Covid-19 vaccines in human trials have reached the last and biggest hurdle: seeking the necessary proof that they actually work, as a U.S. advisory panel suggested a way to ration Tuesday. limited first doses once a vaccine wins. approval.
AstraZeneca announced Monday that its vaccine candidate has entered the final testing phase in the United States. The Cambridge, England-based company said the study will involve up to 30,000 adults of various racial, ethnic and geographic groups.
Two other candidate vaccines began final testing this summer in tens of thousands of people in the U.S. One was created by the National Institutes of Health and manufactured by Moderna Inc., and the other developed by Pfizer Inc. and BioNTech of Germany. .
“ Having a single vaccine in the final stage of trials eight months after discovering a virus would be a remarkable achievement; to have three at that time and more on the way is extraordinary, ” Health and Human Services Secretary Alex Azar said in a statement.
NIH Director Francis Collins tweeted that his agency “ is supporting multiple vaccine trials as more than one may be needed. We have all our hands at work. ”
AstraZeneca said development of the vaccine, known as AZD1222, is progressing globally with late-stage trials in the UK, Brazil and South Africa. More trials are planned in Japan and Russia. The possible vaccine was invented by the University of Oxford and a partner company, Vaccitech.
Meanwhile, a US advisory panel published a preliminary plan on how to ration the first doses of vaccine on Tuesday. The National Academies of Sciences, Engineering and Medicine proposed to administer the first doses of the vaccine _ initial supplies are expected to be limited to 15 million people _ to high-risk healthcare workers and first responders.
Next, priority would be given to older residents of nursing homes and other crowded facilities and to people of all ages with health conditions that put them at significant risk. In subsequent waves of vaccinations, teachers, other school personnel, workers in essential industries, and people living in homeless shelters, group homes, prisons and other facilities would receive the vaccines.
Healthy children, young adults, and everyone else wouldn’t get the first shots, but they could get them once supplies increase.
The National Academies will solicit public comment on the plan through Friday.
There is a good reason why so many Covid-19 vaccines are being developed.
“ The first vaccines that come out will probably not be the best vaccines, ” Dr. Nicole Lurie, who helped lead planning for a pandemic under the Obama administration, told a University of Minnesota vaccine symposium.
There is no guarantee that any of the leading candidates will turn out well, and the bar is higher than for Covid-19 treatments, because these vaccines will be administered to healthy people. The final tests, experts stress, must be performed on large numbers of people to see if they are safe enough for mass vaccinations.
They are made in a wide variety of ways, each with its own pros and cons. One problem: Most of the leading candidates are being tested with two doses, lengthening the time it takes to get a response and, if one works, to fully vaccinate people.
Other: they are all shots. Vaccine experts are closely following the development of some nasal spray alternatives that could begin the first step of human testing later this year, late in the race, but possibly advantageous against a virus that sneaks into respiratory tract.
For now, here is a scorecard of vaccines that have already started or are nearing end-stage testing:
VACCINES WITH GENETIC CODE
Candidates from Moderna and Pfizer began Phase 3 testing in late July.
None use the actual coronavirus. Instead, they are made with the genetic code for the “ spike ” protein that coats the surface of the coronavirus. Inject the vaccine that contains that code, called mRNA, and the body’s cells will produce a harmless spike protein, just enough for the immune system to respond, priming it to react if it later finds the real virus.
These mRNA vaccines are easier and faster to manufacture than traditional vaccines, but it is a new and unproven technology.
VACCINES FOR TROYAN HORSE
The University of Oxford and Britain’s AstraZeneca are making what scientists call a “ viral vector ” vaccine, but a good analogy is the Trojan horse. The injections are made with a harmless virus _ a cold virus that normally infects chimpanzees _ that carries the genetic material of the spike protein to the body. Again, the body makes some spike proteins and primes the immune system, but it’s also a fairly new technology.
Two possible competitors are made with different human cold viruses.
The injections by Johnson & Johnson began initial human studies in late July. The company plans to begin Phase 3 testing in September on up to 60,000 people in the US and elsewhere.
The government of China authorized the emergency use of CanSino Biologics adenovirus injections in the military prior to any final testing.
VACCINES FOR THE DEAD
Making vaccines by growing a virus that causes disease and then killing it is a tried and true approach – it’s the way Jonas Salk’s famous polio vaccines were made. China has three so-called “ inactivated ” vaccine candidates against Covid-19 manufactured in this way.
Sinovac has its candidate’s final studies underway in Brazil and Indonesia. Competitor SinoPharm has announced plans for final tests in a few other countries.
Safely brewing and then removing the virus takes longer than newer technologies. But inactivated vaccines give the body a sneak peek at the germ itself rather than just that single spike protein.
PROTEIN VACCINES
Novavax makes “ subunit protein ” vaccines, growing harmless copies of the coronavirus spike protein in the lab and packaging them into virus-sized nanoparticles.
There are protein-based vaccines against other diseases, so it is not as new a technology as some of its competitors. But only recently did she finish her first-pass study; The US government’s Operation Warp Speed is targeting advanced testing later in the fall.
AstraZeneca announced Monday that its vaccine candidate has entered the final testing phase in the United States. The Cambridge, England-based company said the study will involve up to 30,000 adults of various racial, ethnic and geographic groups.
Two other candidate vaccines began final testing this summer in tens of thousands of people in the U.S. One was created by the National Institutes of Health and manufactured by Moderna Inc., and the other developed by Pfizer Inc. and BioNTech of Germany. .
“ Having a single vaccine in the final stage of trials eight months after discovering a virus would be a remarkable achievement; to have three at that time and more on the way is extraordinary, ” Health and Human Services Secretary Alex Azar said in a statement.
NIH Director Francis Collins tweeted that his agency “ is supporting multiple vaccine trials as more than one may be needed. We have all our hands at work. ”
AstraZeneca said development of the vaccine, known as AZD1222, is progressing globally with late-stage trials in the UK, Brazil and South Africa. More trials are planned in Japan and Russia. The possible vaccine was invented by the University of Oxford and a partner company, Vaccitech.
Meanwhile, a US advisory panel published a preliminary plan on how to ration the first doses of vaccine on Tuesday. The National Academies of Sciences, Engineering and Medicine proposed to administer the first doses of the vaccine _ initial supplies are expected to be limited to 15 million people _ to high-risk healthcare workers and first responders.
Next, priority would be given to older residents of nursing homes and other crowded facilities and to people of all ages with health conditions that put them at significant risk. In subsequent waves of vaccinations, teachers, other school personnel, workers in essential industries, and people living in homeless shelters, group homes, prisons and other facilities would receive the vaccines.
Healthy children, young adults, and everyone else wouldn’t get the first shots, but they could get them once supplies increase.
The National Academies will solicit public comment on the plan through Friday.
There is a good reason why so many Covid-19 vaccines are being developed.
“ The first vaccines that come out will probably not be the best vaccines, ” Dr. Nicole Lurie, who helped lead planning for a pandemic under the Obama administration, told a University of Minnesota vaccine symposium.
There is no guarantee that any of the leading candidates will turn out well, and the bar is higher than for Covid-19 treatments, because these vaccines will be administered to healthy people. The final tests, experts stress, must be performed on large numbers of people to see if they are safe enough for mass vaccinations.
They are made in a wide variety of ways, each with its own pros and cons. One problem: Most of the leading candidates are being tested with two doses, lengthening the time it takes to get a response and, if one works, to fully vaccinate people.
Other: they are all shots. Vaccine experts are closely following the development of some nasal spray alternatives that could begin the first step of human testing later this year, late in the race, but possibly advantageous against a virus that sneaks into respiratory tract.
For now, here is a scorecard of vaccines that have already started or are nearing end-stage testing:
VACCINES WITH GENETIC CODE
Candidates from Moderna and Pfizer began Phase 3 testing in late July.
None use the actual coronavirus. Instead, they are made with the genetic code for the “ spike ” protein that coats the surface of the coronavirus. Inject the vaccine that contains that code, called mRNA, and the body’s cells will produce a harmless spike protein, just enough for the immune system to respond, priming it to react if it later finds the real virus.
These mRNA vaccines are easier and faster to manufacture than traditional vaccines, but it is a new and unproven technology.
VACCINES FOR TROYAN HORSE
The University of Oxford and Britain’s AstraZeneca are making what scientists call a “ viral vector ” vaccine, but a good analogy is the Trojan horse. The injections are made with a harmless virus _ a cold virus that normally infects chimpanzees _ that carries the genetic material of the spike protein to the body. Again, the body makes some spike proteins and primes the immune system, but it’s also a fairly new technology.
Two possible competitors are made with different human cold viruses.
The injections by Johnson & Johnson began initial human studies in late July. The company plans to begin Phase 3 testing in September on up to 60,000 people in the US and elsewhere.
The government of China authorized the emergency use of CanSino Biologics adenovirus injections in the military prior to any final testing.
VACCINES FOR THE DEAD
Making vaccines by growing a virus that causes disease and then killing it is a tried and true approach – it’s the way Jonas Salk’s famous polio vaccines were made. China has three so-called “ inactivated ” vaccine candidates against Covid-19 manufactured in this way.
Sinovac has its candidate’s final studies underway in Brazil and Indonesia. Competitor SinoPharm has announced plans for final tests in a few other countries.
Safely brewing and then removing the virus takes longer than newer technologies. But inactivated vaccines give the body a sneak peek at the germ itself rather than just that single spike protein.
PROTEIN VACCINES
Novavax makes “ subunit protein ” vaccines, growing harmless copies of the coronavirus spike protein in the lab and packaging them into virus-sized nanoparticles.
There are protein-based vaccines against other diseases, so it is not as new a technology as some of its competitors. But only recently did she finish her first-pass study; The US government’s Operation Warp Speed is targeting advanced testing later in the fall.
.
