The COVID-19 pandemic caused by the coronavirus SARS-CoV-2 has dominated life around the world this year. Now, the FDA has granted Emergency Use Authorization for two vaccines, one from Pfizer/BioNTech and one from Moderna. How will they alter the course of the pandemic? We offer listeners a coronavirus update for the close of this pandemic year of 2020.
Dr. Ralph Baric has been studying coronaviruses for three decades, and he has a wealth of information about SARS-2.We check in with him for the third (and last) time this year.
We get a quick summary on how these new messenger RNA vaccines work. In animals, they stimulate a very robust immune reaction with neutralizing antibodies. They seem to do that in humans as well. In addition, they have excellent efficacy, much better than the original goal of 50 percent or higher. The AstraZeneca vaccine uses a different approach, but it also seems to provoke a strong immune response.
There are a number of things we don’t know yet about the new COVID-19 vaccines. For example, we know that they keep people from becoming seriously ill, but we don’t know if they prevent low-level or asymptomatic infections in nasal tissue. Moreover, we do not yet have evidence on whether they can prevent transmission of the coronavirus. We will need more research to determine that in the future.
Preventing infection is only part of the story. To overcome this pandemic, we also need good treatments for people who are infected. The monoclonal antibody treatments are helpful when used appropriately, but not enough people are getting access to them. Antiviral treatments such as ivermectin, remdesivir and EIDD-2801 are promising. However, direct-acting antiviral compounds such as EIDD-2801 are most effective when given early in the course of infection. We haven’t yet figured out how to administer them reliable to people who have recently become infected
New research suggests that some people may have been exposed to this novel coronavirus before the first infections were reported from Wuhan, China, in December, 2019. There is a lot of travel between Asia, the US and Europe that could have helped to spread it. The focus now is on new strains with mutations that help them spread more efficiently. How will viral mutations affect vaccine efficacy? We don’t yet know if SARS-CoV-2 will end up mutating so quickly that we will need a new vaccine every year or two, as we do for the flu. That doesn’t seem likely right now, but we keep learning new things for the coronavirus update
Many people have talked about achieving herd immunity, and we wonder if that is a realistic goal. There are two ways to make sure that enough people are immune to the virus that it doesn’t spread through the population unchecked as it has in 2020. The first and by far the preferred way is to vaccinate a lot of people. Most experts estimate that when at least 70 percent of us have been vaccinated, SARS-CoV-2 will have trouble spreading to people who have not been vaccinated. The other way to achieve herd immunity, by letting people become infected with the coronavirus, would result in an unacceptably high death toll, not to mention disabilities among survivors with long COVID.
In this coronavirus update, we ask Dr. Baric for his predictions for future waves. Under worst-case scenarios, we could see many hundreds of thousands more deaths in the US. Even under the best circumstances, we may see another 200,000 or 300,000 deaths in this country before the pandemic is controlled. Dr. Baric offers his advice for safe celebrations as we bring the year to a close. He also offers an assessment for how we can use this experience to overcome the next emerging pathogen before it becomes a pandemic.
Ralph Baric, PhD, is the William R. Kenan, Jr. Distinguished Professor in the Department of Epidemiology and Professor in the Department of Microbiology and Immunology of the University of North Carolina at Chapel Hill. He is a Harvey Weaver Scholar from the National Multiple Sclerosis Society and an Established Investigator Awardee from the American Heart Association. In addition, he is a World Technology Award Finalist and a fellow of the American Association for Microbiology. In this recent study by Dr. Baric and his colleagues, older adults responded well to an mRNA vaccine against SARS-2 (New England Journal of Medicine, Dec. 17, 2020).
He has spent the past three decades studying coronaviruses and is responsible for UNC-Chapel Hill’s world leadership in coronavirus research. For these past three decades, Dr. Baric has warned that the emerging coronaviruses represent a significant and ongoing global health threat, particularly because they can jump, without warning, from animals into the human population, and they tend to spread rapidly.