Expert Q&A: KCH's Jeff Woods on COVID-19 and epidemiology questions
The College of Applied Health Sciences has experts in many areas that have been affected by the COVID-19 outbreak. Periodically we will ask these experts about how their areas of expertise have been impacted and what we can expect in a post-COVID-19 world. Today, we ask KCH professor Jeff Woods about complicating risk factors, vaccine production and virus spread.
Q: What are some of the complicating risk factors of COVID-19?
A: There seem to be many conditions, including advanced age, that complicate the severity of SARS-CoV-2 infection. Others include cardiovascular disease, asthma, obesity, high blood pressure, and diabetes. Exacerbation of COVID-19 symptoms in those with underlying respiratory or heart problems is self-evident, but we do not know why other comorbidities make some susceptible to it. In addition, recent reports indicate that even young adults can experience hospitalization and severe symptoms. On the other hand, many others have tested positive without symptoms. Bottom line is that it is too early to tell all the factors that may make us susceptible to COVID-19 and it is too early to understand the mechanisms of why some condition increase or reduce severity. One factor that is always difficult to ascertain is the viral load of the inoculum that an infected person experienced. High loads should lead to more severe consequences. This is why wearing masks and reducing exposure to people via social distancing or reducing contact time is so important not just to prevent infection but also to lessen the viral load of exposure.
Q: The Spanish Flu erupted in spring, went dormant in the summer and then came back in the fall. Do you expect a similar pattern with COVID-19?
A: I do not think we know what to expect. This is a new virus we don’t know a lot about and comparing social dynamics as it relates to virus transmission across a century of time (e.g. comparing with Spanish Flu) is fraught with interpretive problems. The main reason that scientists believe that some viruses are seasonal have to do with living conditions—more people inside during winter, therefore greater chance of exposure and spread between people. In addition, some viruses are susceptible to light and humidity, both of which are lower in winter months thereby reducing fomite transmission.
Q: Dr. Fauci expressed hope for a vaccine within the next 6-8 months. But we haven’t been able to find a vaccination for the common cold. Is there any reason to have any greater hope for COVID-19 than we’ve had for these common diseases that have been around for decades?
A: Yes, I think so. The common cold has never shut down our economy before or caused significant human suffering or death. COVID-19 has. This fact alone has motivated much research and development regarding a vaccine. There is currently an unprecedented and well-funded effort to realize one or more SARS-CoV-2 vaccines in the near future. Scientists are also using different strategies, either targeting viral RNA or the ‘spike’ protein of the virus that increases the probability of success. That said, there are no guarantees in a war with a virus. One reason that you need an annual influenza vaccine is that influenza can mutate rather quickly. There is evidence that SARS-CoV-2 mutates more slowly, which is a good thing when trying to develop a universal vaccine against it.
Q: For people who have aging parents or relatives, how do we best protect them?
A: The best thing to do, at least until we get a successful vaccine, is to isolate them against potential infection. This means mask wearing and social distancing of at least six feet, but maybe more. This is important for older adults because their immune systems undergo senescence making the system less effective at combating pathogens or responding to vaccinations. If they get infected, there is a higher chance of a poor outcome.
Q: When will we know that the pandemic is lessening in the U.S.?
A: When the number of laboratory confirmed COVID cases (i.e. virus testing) drops and stays low for a significant time period. Symptom confirmed cases are not a great indicator because some people are infected and remain asymptomatic. Antibody tests tell us about individual exposure and in the case of some other viruses (e.g. influenza) indicates a certain level of protection from reinfection. However, at present, we do not know if antibody presence predicts protection against COVID. This big unanswered question needs to be answered. In short, we do not know if prior exposure leads to protective immunity or whether people can become reinfected after an initial exposure.