Pamela Bjorkman Answers Community's Questions on COVID-19

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As part of Caltech's new public communication initiative, Science Exchange, Bjorkman leads a webinar for the community on the novel coronavirus.

Pamela Bjorkman Answers Community's Questions on COVID-19

July 13, 2020

Pamela Bjorkman, the David Baltimore Professor of Biology and Bioengineering, investigates how the immune system reacts to viruses. Bjorkman aimed to shed light on the science behind the pandemic in a recent Caltech webinar, where she provided an introduction to viruses, antivirals, and vaccines in the context of the virus that causes COVID-19.

A few of the questions she answered:

Is there a means to determine whether a virus has developed naturally in the wild versus one synthesized or modified in the laboratory?

It's unfortunate that conspiracy theories are being spread (sort of like a virus) about the origins of SARS-CoV-2. When you look at the sequence of SARS-CoV-2, it's clear that it evolved from a particular bat coronavirus. There's no way, in my mind, that a scientist could design a viral sequence based on a bat coronavirus sequence or any other sequence to ensure that it would be very highly transmissible and also induce serious illness. From what we understand about COVID-19, the progress to ARDS (acute respiratory distress syndrome) is caused by our own immune system's response to the virus. I teach immunology every year, and I would have no idea how to design a coronavirus (or any other virus) to produce ARDS. Nor would any other scientist. So even if you believe that scientists would deliberately synthesize a deadly virus in the laboratory for release to the public, there's no way of someone knowing what they would have to start with and modify (e.g., a bat coronavirus) to make it easily transmissible among humans.

Even if we develop a vaccine against COVID-19 quickly, it is not going to be a cure. Do we know how quickly COVID-19 evolves, and how do we deal with such moving targets? Any lessons we can borrow from the experience of developing flu and HIV vaccines (or failure to do so)?

The formulation of the annual flu vaccine is chosen by the WHO, which predicts which three or four influenza strains are likely to circulate during the next flu season. So, flu vaccines work best when the prediction is correct. Yes, there is information about how quickly SARS-CoV-2 evolves, and the good news is that it evolves more slowly than flu and a lot more slowly than HIV-1. Even though SARS-CoV-2 may not mutate to develop resistance, we might need an annual coronavirus vaccine if a vaccine and a natural infection produce only short-lived immunological memory.

Watch the entire webinar on Caltech's YouTube page.

Read more interesting and accessible scientific articles on the newly launched Caltech Science Exchange.