week 3 quarantine current event

Science & Math

Search speeds up for vaccine against the new coronavirus

This conceptual illustration shows vials of blood in a centrifuge being tested for coronavirus infection. Today, several companies are working to develop vaccines that will prevent the spread of the new coronavirus. Graphic: KTSDesign/Science Photo Library/Getty Images 

By Tina Hesman Saey, Science News for Students

A mystery illness emerged in China late last December. As word of its spread got out, researchers at Inovio Pharmaceuticals paid close attention. This was even before anyone knew what was making people sick, a new coronavirus.

Inovio, based in San Diego, Calif., is no stranger to such viruses. A different novel coronavirus had emerged in 2012. It, too, caused potentially deadly infections. This disease would come to be known as MERS. (That's short for Middle East respiratory syndrome.) Inovio became one of the first companies to develop a vaccine against MERS. (That vaccine is still experimental.)

Early in the latest outbreak, Chinese researchers posted details of the genetic makeup of the virus that was making so many people sick. The disease, which causes fevers, pneumonia and other serious symptoms, is now called COVID-19. The virus responsible has just been named SARS-CoV-2. Based on Inovio's work on the MERS vaccine, its scientists sprang into action. They thought they might be able to roll out a version of the MERS drug to tackle COVID-19.

Kate Broderick is Inovio's senior vice president for research and development. "We'd all hoped that there would be enough overlap that our previously developed MERS vaccine would be helpful in this case," she recalls. Like MERS and another severe coronavirus — one that causes the disease SARS — the new virus uses RNA as its genetic material.

But in the end, Inovio's researchers found, SARS-CoV-2 was too different for its vaccine against MERS to take down this virus. So the scientists set to work on creating a new vaccine.

Its design relies on a relatively new approach. Vaccines usually are made from weakened or killed forms of viruses or parts of viruses. Those viral parts may include some proteins that serve as building blocks of the germ. When injected into somebody new, their immune system recognizes these viral bits as an invader. It now makes antibodies. These should help to fight off future invasions by the whole, live virus. But to make enough vaccine for millions of people, it can take months or even years to grow enough disabled virus or to purify enough viral proteins.

So for their SARS-CoV-2 vaccine, Inovio scientists took a different approach. They converted the virus's RNA into DNA. They also selected pieces of the virus that computer models suggested would prod the immune system into making antibodies. Then they inserted selected bits of the DNA into bacteria. Those bacteria now used instructions in the bits of DNA to make large quantities of the viral protein. And it's those proteins that will be used in the vaccine.

This approach drastically shortens how long it takes to make a vaccine, Broderick says. Normally, it might take two to three years. For Inovio's product, it took three hours to design. Then it took roughly a month to make, Broderick reports.

The company started testing the vaccine in animals at the beginning of this month. It hopes to begin safety tests in people by early summer.

Even so, Inovio's vaccine is still at least a year away from widespread use. As the number of cases of COVID-19 continues to rise, several other research teams are also racing to develop vaccines and treatments. They, too, are using unusual ways to fight the new virus.

Novel vaccines for a novel coronavirus

Messenger RNAs are copies of protein-making instructions found in the DNA of genes. Cells "read" these instructions to build proteins. Researchers are now developing a messenger RNA — or mRNA — vaccine. Its goal would be to stimulate the body to produce vaccine components.

Part of the research team behind this project works for Moderna. It's a Cambridge, Mass.–based biotechnology company. The other scientists work for the National Institute of Allergy and Infectious Diseases, or NIAID. It's one of the National Institutes of Health.

Kizzmekia Corbett is an immunologist at NIAID's Vaccine Research Center. It's in Bethesda, Md. She's also the scientific leader on the center's effort to develop a COVID-19 vaccine. Scientists on this project have selected portions of the SARS-CoV-2 virus that may spark a vigorous immune reaction. This mRNA vaccine, she explains, would then tell human cells which viral proteins to make.

"We're literally giving the cells a genetic code," Corbett says. It's being delivered as RNA. And it will tell cells, 'Hey, make this protein.'"

Those proteins — Corbett wouldn't say which ones — will then prod the immune system to make antibodies against the virus. Here, the body does all of the protein-making work. That means researchers can skip the time-consuming and costly step of making those proteins in some lab.

This approach could be used in making vaccines against future new coronaviruses or other new infectious diseases, Corbett says. "What we feel we have developed," she adds, "is [a new way] to quickly deploy a vaccine if another novel coronavirus should pop up."

Other mRNA vaccines for other infections are still undergoing tests.

On February 24, Moderna announced that the new mRNA vaccine is ready for testing in people. It will be tested first in 45 adults to see if it is safe. If it passes that test, researchers will do more testing to see if it also protects against the virus.

But even if the vaccine works, there is another problem. The researchers don't yet have a company willing or able to produce the huge amounts of mRNA doses. And that would be needed to make enough vaccine to treat a large share of the public.

Beating vaccines to the punch

People who get over infections will retain antibodies to the germ that made them sick. It may stick around in their blood for years — even decades. Those antibodies can give them some protection when that person later encounters a similar germ. But those antibodies also might protect others.

How? Give people a shot of somebody else's protective antibodies. This might prevent infections in healthy people. It might even treat infections in people who are already sick. And these injections could work faster than vaccines.

Vaccines can take weeks or months to prod the immune system into making enough antibodies to stave off an infection.

Regeneron is now developing antibodies against the COVID-19 virus. For instance, the team has learned more about which parts of the virus make the best antibody targets. The proteins on the surface of a virus that are needed to infect cells — such as the spike protein — generally are best.

Regeneron researchers have made SARS-CoV-2 proteins in the lab. They have injected them into mice that have human versions of antibody-producing genes. These "humanized" mice make human antibodies. Such mice could provide a ready supply of antibodies to treat people.

As soon as those antibodies are available, the company hopes to run lab tests on how well they work against the virus. If they work well, safety tests in animals and people might be able to start soon.

The team also hopes to get some blood from people who recovered from COVID-19 and retrieve some of their antibody-producing cells. But, mining antibodies from people's blood won't easily yield enough to treat masses of people.

As these programs all show, getting a treatment for a new virus is not something that can be done overnight. It can take months or years.

So in the midst of a new outbreak, "You're not going to just pull a vaccine out of your pocket," notes Anthony Fauci. He directs NIAID in Bethesda, Md. If the current outbreak proves to be "really bad," the FDA might allow emergency use of promising vaccines that haven't completed their full safety and efficacy testing. But researchers won't know for at least six months whether any of the vaccines in development will help against COVID-19 virus.

Other strategies to fight the new virus, including using existing drugs designed to fight other diseases (such as AIDS and hepatitis C), also are underway. But no one knows which ones are winners. So for now, people exposed to the new virus must rely on their own immune systems and care from doctors and nurses to fight off COVID-19.