UF Geography Lecturer answers Reddit AMA questions on pandemics

Gabriela Hamerlinck, a lecturer in the Geography Department at the University of Florida, teaches students about the ins and outs of pandemics.

Hamerlinck, a cultural ecologist who focuses on vector-borne illnesses and medical geography, began to incorporate COVID-19 into her Spring 2020 course material as the global pandemic unfolded in real time. Check out some of the questions and answers from her Reddit AMA on the social, demographic, economic and environmental contexts of historical and modern epidemics:

Q: Do you have any insight on what sorts of models have been used to drive the pandemic response? I remember learning about things like SIR (during) undergrad, but I was wondering what the state-of-the-art looks like.

A: SIR models are simple, but can be very powerful! The type of model you develop depends on what your question is, what sort of data you have to parameterize the model with, and any assumptions you’re making. You can start with a simple SIR model and build it up to fit your needs – which is what I do when I start modeling a new disease because it helps to understand the basic dynamics of the system.

Nina Fefferman from the University of Tennessee at Knoxville gave a great webinar about applied math in real-time pandemic response. It was recorded and is very approachable if you wanted to watch it: https://youtu.be/Ewuo_2pzNNw. The National Institute for Mathematical and Biological Synthesis (NIMBioS) has some other webinars that deal with modeling and disease: https://www.nimbios.org/webinars

Q: How do you see today’s technology and geopolitics shaping how information is shared?

A: We have been trained to expect immediate information at our fingertips. Social media can be a force for good – where you can find and share correct information with the whole world. But the downside is that we also have the extremely fast propagation of false information. That “fake news” puts millions at risk and can be very damaging to our pandemic response. The UN put out a statement on fake news and risk during COVID19 that you might be interested in.

Q: Do you have an informed “best guess” opinion on the future global availability of a potential vaccine? (Or barriers to same?)

A: There are so many barriers to the development of an effective vaccine. The timeline is long – for a very good reason. We need the vaccine to be safe, as well as effective. The NY Times has a fun interactive chart where you can see how quick (or how slow) vaccine development could take.

Q: There seems to be a lot of discussion about whether or not having the COVID-19 antibodies in your system will give you immunity to COVID-19. Is it a common occurrence to have the antibodies for a virus in your system but not be immune to that virus?

A: I haven’t been following the antibody testing for COVID-19 as closely as I probably should be, but here are my thoughts. We (the scientific and medical communities) do not know how long it takes for your body to develop antibodies to the coronavirus after exposure. We also do not know long long any inferred immunity will last once you do develop antibodies. We also are not sure how effective an immune response will be, so even if you do have immunity, it might not be 100%. There are lots of researchers working on answering these questions, but that science is happening right alongside this novel (aka brand new) virus, so it will take some time.

To compare to the flu, we need to get an annual flu shot to make sure that we have the antibodies necessary to keep us safe from this year’s flu strains. In order to make a flu shot, scientists look at the “worst” strains from this year and predict (with amazing accuracy) what next year’s influenza threat is going to look like. The vaccine is developed to provide protection again a combination of those predicted strains. Sometimes, the flu virus evolves in an unexpected way, and the flu shot that was developed is not as effective. You still have antibodies that recognize the virus, but do not infer much protection. This is a similar story to dengue if you’re interested in more examples!

Q: Coronavirus seems to have come out of the blue, but we sort of had warnings with SARS and MERS. What could we have learned from SARS and MERS that we ignored? What do you think is coming after coronavirus?

A: I think we missed the mark on our pandemic preparedness planning. Hindsight is 20/20, so it is easy to be critical now, but I think there will be a lot of countries taking a close look at what worked and what didn’t as we begin to recover and plan for the next pandemic. I think the next pandemic will be of zoonotic origin (a pathogen that spills over into human populations from an animal source). Humans are continuing to encroach on wild areas, which brings us into close contact with animals, therefore increasing the opportunity for the spill over event to happen.

Q: There seems to be a lot of controversy about this virus. In your opinion, how can scientists and other professionals whose responsibility it is to inform the public of infectious disease developments best communicate the seriousness of this epidemic to people?

A: The nature of science is cyclical, and I think this is widely misunderstood, which leads to a lot of perceived controversy. As scientists, we are continually updating our hypotheses and predictions based on new data or evidence that is being collected. Just because a question is answered once, does not mean we can’t go back and re-evaluate it with new data. Since the science and the pandemic are occurring at the same time, it is difficult to keep up all the new information that is coming out every day.

Q: As a modeling question, how do you factor the possibility of viral mutations into epidemiological forecasting?

A: You can incorporate mutations by adding in some dynamic parameters to your model. The good news is that we have a pretty good idea of how genetic mutations work, so we are able to incorporate that knowledge into mathematical models. For example, we can figure out how often an A->T nucleotide mutation will occur in a species and allow for that variability in the model parameter associated with that type of transversion mutation.

Q: Would it be possible for a vector-borne disease to cause a pandemic or would it be difficult since certain organisms can’t live in certain environments? Are there any vector-borne diseases that you think pose a significant threat globally right now?

A: Vector-borne diseases might be able to turn into a pandemic, but it would be difficult because of the reasons you mention. If a pathogen had a wide variety of hosts that were adapted to many climates and landscapes, it would pose a bigger pandemic risk than what we’ve got now. You have to consider how you define “threat” for your last question. Do you mean threat to the global economy, threat to food security, threat to human life in terms of amount of people getting sick/dying, etc. I bring this up to my students all the time!