This post was updated June 29, 2020 to include comments from Alexis Kalergis.
A Colorado team says their work on a COVID-19 vaccine is progressing. Other vaccines are much further down the testing pipeline, but none have crossed the finish line yet.
Ray Goodrich directs the Infectious Disease Research Center at Colorado State University. Results haven’t yet been published in a peer-reviewed journal, but Goodrich said studies in about 40 hamsters have shown the potential vaccine is successful on two fronts: It causes the animals to mount an immune response, and it appears to protect them from the disease.
Animals that received the vaccine received two doses, spaced three weeks apart. Control animals were given salt water instead of a vaccine. All animals were then exposed to high concentrations of the live virus in their nostrils.
“In those animals that did not receive the vaccine, we saw high levels of virus present in the lungs, present in the trachea, present in samples that we took from various organs within the body,” said Goodrich. “In the groups that were vaccinated, there’s no evidence of adverse effects and no evidence the disease has actually been occurring."
And, he said, "There was an increase in what’s called neutralizing antibody.” That's a type of antibody that blocks the virus from entering cells, and appears to stick around longer than other types.
There are at least eight different approaches for how to make a vaccine, from a new approach that involves using snippets of the virus’ genetic material to the tried-and-true method of using whole, killed virus. That’s the approach of the original polio vaccine, and vaccines against rabies, hepatitis A and whooping cough. It’s the route the CSU researchers have taken.
“But we're using a new twist in the way that we do that, that we believe will be faster, more efficient, more effective at generating a vaccine candidate, that you don't need to administer a whole lot of to a patient in order to induce a good immunizing effect,” Goodrich said.
According to NPR, about 200 vaccines are currently in development. Some are already being tested in humans.
Goodrich said SolaVAX still has a number of research hoops to jump through before reaching that stage, including additional animal testing and proving that it’s possible to scale up production of the vaccine.
A group of doctors and scientists with the Coalition for Epidemic Preparedness Innovations wrote in the journal NEJM that the newer vaccine approaches, using snippets of virus DNA or RNA, have the “greatest potential” when it comes to speedy production. But, they wrote, “It’s far from certain that these new platforms will be scalable or that existing capacity can produce sufficient quantities of vaccine fast enough. It’s therefore critical that vaccines also be developed using tried-and-true methods, even if they may take longer to enter clinical trials or to result in large numbers of doses.”
Alexis Kalergis, director of the Millennium Institute on Immunology and Immunotherapy at the University of Chile Santiago, agreed that large-scale production could prove to be the Achilles heel of newfangled RNA vaccines. But the traditional approach of inactivated viruses isn't foolproof, either.
"This technology seems useful to produce large amounts of inactivated viruses," he said. "However, it is important to be cautious about the immune response induced by vaccines based on inactivated virus. It has been shown before that for some viruses, such as RSV, a chemical inactivation process can promote an antibody-induced disease or even disease enhancement due to an abnormal activation of the immune response."
He said it's also very important to prove that the virus can't restore itself after inactivation.
If successful, one advantage of the CSU vaccine candidate is that the key ingredient -- inactivated virus -- is produced in a type of portable device that's already used in medical facilities in a number of countries for purifying blood donations. In the U.S., it’s use in blood transfusions is currently being studied in a clinical trial involving 620 transfusion patients.
As Kalergis and his colleagues wrote in 2018 in the journal Frontiers in Immunology, the ability to manufacture vaccines locally is especially important during pandemics, when supplies may be stretched thin and countries may not be able to rely on the usual vaccine manufacturers. That ability, the scientists wrote, should be considered "a matter of national safety."
This story was produced by the Mountain West News Bureau, a collaboration between Wyoming Public Media, Boise State Public Radio in Idaho, KUNR in Nevada, the O'Connor Center for the Rocky Mountain West in Montana, KUNC in Colorado, KUNM in New Mexico, with support from affiliate stations across the region. Funding for the Mountain West News Bureau is provided in part by the Corporation for Public Broadcasting.