Home News Those coronavirus vaccines leading the race? Don’t ditch the masks quite yet


Those coronavirus vaccines leading the race? Don’t ditch the masks quite yet

by Ace Damon

Almost $ 6 billion was allocated. Clinical trials are entering a third crucial phase, and Operation Warp Speed is approaching the goal of providing 300 million doses of a COVID-19 vaccine by January.

But when Americans line up to receive their immunizations, the vaccine they receive may not be what they expect. The popular notion of a vaccine – a shot in the arm that prevents diseases like measles, polio, or shingles for years or a lifetime – may not apply.

Under the recently released federal guidelines, a COVID-19 vaccine can be authorized for use if it is safe and proves to be effective in up to 50% of people who receive it. And “effective” does not necessarily mean preventing people from getting sick with COVID-19. It means minimizing the most severe symptoms, experts say.

“We should expect the SARS-CoV-2 vaccine to be similar to the influenza vaccine,” said Dr. Kathleen Neuzil, director of the Vaccine Development Center at the University of Maryland. “This vaccine may or may not prevent people from being infected with the virus, but it keeps people out of the hospital and the ICU.”

Even with low expectations, the development of a vaccine against a virus that nobody knew for seven months is considered remarkable. One assessment calls this “the compression of six years of work into six months”.

Of the more than 150 vaccines underway in the world, Operation Warp Speed ​​identified 14 “promising candidates. ”(A vaccine being developed by ImmunityBio, based in El Segundo, led by Dr. Patrick Soon-Shiong, owner of the Times, is among 14. It has not yet been tested on humans.)

Of those 14, Seven have been designated as pioneers, including three whose initial clinical trial results have undergone independent evaluation.

The vaccine being developed by Moderna and the National Institutes of Health was considered “promising” in an editorial published in the New England Journal of Medicine, and two studies in the Lancet conveyed a similar message for vaccines under development at Oxford University and by the Chinese . CanSino company.

These vaccines elicited an immune response in people taking part in initial tests, but inducing an immune response does not always mean success in fighting a disease. For example, scientists recently developed a vaccine for another respiratory virus that increased antibodies but failed your phase 3 clinical trial.

While there is no way to predict what’s coming, experts say, the first round of vaccines with COVID-19 is unlikely to eliminate the need for other public health measures, such as masks and social detachment.


The 50% minimum efficacy recommendation issued at the end of June by the Food and Drug Administration would likely ease the burden on hospitals. And, whatever the extent to which the COVID-19 vaccine prevents infection, it can reduce the spread of the virus and help create immunity pockets across the country, said Peter Hotez, dean of Baylor’s National School of Tropical Medicine. College of Medicine.

“Ideally, you want an antiviral vaccine to do two things,” said Hotez. “First, reduce the likelihood that you will become seriously ill and go to the hospital, and two, prevent infection and therefore stop the transmission of the disease.”

In that case, he added: “the bar doesn’t look that high”.

Developing a vaccine capable of inducing “immunity to sterilization” – that is, the ability to prevent the virus from causing an infection – takes time and research, which may not be possible, as the death toll continues to increase and the recession continues. makes it deeper. However, with so many companies looking for this vaccine, there is hope that one of them can actually achieve it.

Dr. Mark Feinberg, CEO of the International AIDS Vaccine Initiative, cites the success of the Ebola vaccine. Not only did it speed up its clinical trials – from the start of Phase 1 to obtain the first results of Phase 3 in 10 months – it was also almost 100% effective in 10 days after the administration of a single dose.

This is not likely to be the case now. “The challenge is that the new coronavirus hasn’t been around long enough,” said Feinberg.

The scientists studied other coronaviruses – SARS and MERS – and mapped the genome of the new coronavirus shortly after the first deaths from COVID-19 were recorded. They identified the spike protein in the virus’s outer layer, which the virus uses to infiltrate the host cell, and created a three-dimensional model of the virus to see how antibodies block the infection by binding to the spike protein.

Even so, scientists still don’t know what immunity to the virus is like. This information usually comes from studying the body’s natural response to disease. The number of T cells and neutralizing antibodies that fight infection may become a model for a vaccine.

But the new coronavirus is not giving up these secrets easily.

Doctors observed a wide range of immune responses to COVID-19, said Feinberg. Some patients produce high levels of neutralizing antibodies, while others produce only low levels.

“The interesting thing is that everyone recovered and we don’t know how they did it,” said Feinberg, former director of science and public health at pharmaceutical giant Merck.

Scientists are also uncertain how long immunity – from a natural infection or a vaccine – lasts and whether an antibody decline in two to three months is a cause for concern.

The third phase of clinical trials can answer some of these questions. Moderna is enrolling 30,000 people for its Phase 3 test, which started on Monday.

“If we get a 60% effective vaccine, we can use the information to identify what distinguishes people who are protected from those who are susceptible,” said Feinberg. “Then we will know what the minimum goal for an immune response is.”

But the absence of this information does not prevent the distribution of a vaccine. Many vaccines are effective, although scientists do not know the amount of antibodies needed to prevent infection. A vaccine may even be effective if it does not prevent infection.

The polio vaccine developed by Jonas Salk does not prevent the poliovirus from infecting the gastrointestinal tract, said Feinberg, but it does prevent the virus from traveling to the central nervous system, where it causes the worst symptom of the disease, paralysis.


With so many questions still unanswered, the effectiveness of a COVID-19 vaccine may not be known until long after Americans receive their doses.

Among the recommendations of the FDA guidelines is a provision for emergency use authorization, allowing the distribution of a vaccine if “the known and potential benefits of a product … outweigh the known and potential risks of the product”.

“I imagine it is likely that the FDA will issue an emergency use authorization if any of the vaccines under development show significant and convincing evidence of efficacy and safety,” said Feinberg, whose research organization is collaborating with Merck to develop a COVID-19 vaccine. .

Under an emergency use authorization, the vaccine could be administered before the completion of Phase 3 trials, potentially helping to flatten the curve, but giving scientists little time to study side effects or understand how it interacts with other vaccines.

Dr Paul Offit, a vaccine specialist at the Children’s Hospital of Philadelphia, raised concerns that the FDA would go green manufacturing and distributing vaccines before the necessary reviews are completed.

Offit fears that a vaccine with limited effectiveness delivered prematurely may give people “a false sense of being protected” and “lead to serious outbreaks of the disease”.

“We must wait for the completion of the Phase 3 trials, no matter how long they take,” he said. “With luck, they can finish in six to nine months.”

But postponing a vaccine delivery date would not align with Operation Warp Speed’s January target.

The Trump administration’s ambitious timeline has led to $ 5.7 billion being allocated to seven companies, and critics like Hotez and Offit wonder whether speed is getting in the way of science.

Dr. Robert Gallo, director of the Institute of Human Virology at the University of Maryland, argues that Operation Warp Speed, a public-private partnership, is “science by committee”, run by some people, when there is a need for debate and debate robust. exchange of information.

“If scientific problems need innovation, there must be wide openings for original thinking and a means of arguing or fighting, without worrying that you cannot be funded,” he said.

Gallo, who co-founded the Global Virus Network, is concerned that the seven leaders of Operation Warp Speed ​​are using the same strategy for their vaccine, one designed to neutralize the spike protein.

If this method proves ineffective, the deadline for delivery of the vaccine will be extended.

“I am sure it is not advisable to put all these eggs in one basket,” he said.


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