The Coronavirus Vaccine Horse-race: 7 Leading Contenders
Scientists have focused on three approaches to developing a vaccine, each with advantages and disadvantages
WASHINGTON – Eight Participants Take the Lead in Race to End the Global COVID-19 Pandemic.
Eight vaccine candidates are being tested in humans in clinics in China, the United States, the United Kingdom and Germany. In addition to them, at least 94 more are at various stages of development..
The Trump administration wants to have millions of doses available before the end of the year, but experts warn that unprecedented speed may be achieved by bypassing security measures, and there is no guarantee that any candidate vaccines will be effective..
“I am concerned that we will not be able to answer key questions about safety and efficacy if we plan to get the vaccine so quickly,” says Paul Offit, director of the Vaccine Education Center at Children’s Hospital of Philadelphia..
The eight candidate vaccines fall into three categories.
The first category can be called the classic method: injection of a killed version of the virus to mobilize the patient’s immune system. Three independent groups of Chinese researchers test inactivated vaccines.
The second method uses one virus to fight another.
Whether it causes COVID-19, Ebola, or the common cold, the virus itself is just a shell containing instructions for making new copies of the virus..
In this new vaccine development strategy, scientists remove instructions from one virus and replace them with instructions to create only a portion of the coronavirus..
The introduction of the modified virus does not cause disease. The virus infects some of the patient’s cells, but instead of copies of the dangerous virus, these cells produce only that very part of the coronavirus. The patient’s immune system reacts to the coronavirus protein and can deal with the intruder later.
This approach is used by two groups of scientists from China and the UK..
The third strategy excludes the middleman. Instead of delivering instructions through a virus, researchers inject the genetic code of a coronavirus element directly into a patient in the form of DNA or RNA..
Two groups are working on RNA vaccines, another is trying to develop a DNA vaccine.
The new methods are faster and more flexible, says Kimberly Taylor, head of biological defense vaccine development at the National Institute of Allergy and Infectious Diseases..
“They are very good for pandemic platforms because they are usually plug and play. They can be produced very quickly and delivered quickly to clinics, ”she explains..
Each technology has its pros and cons.
“We’re not going to put all our eggs in one basket,” says Walter Orenstein, deputy director of the Emory University Vaccine Center. “Different groups are looking at what will work and what may not.”.