Perry World House and the Penn Medicine Center for Research on Coronavirus and Other Emerging Pathogens hosted a discussion about lessons learned during the COVID-19 crisis and how to prepare for future pandemics. Virologists and center co-directors Frederic D. Bushman and Susan R. Weiss discussed the pandemic’s first year and what lies ahead in a conversation moderated by Harvey Rubin, professor of medicine and computational biology.
After an introduction by Perry World House Director Michael Horowitz, Rubin kicked off the discussion by emphasizing that “this is not the last pandemic,” and the importance of learning from COVID-19 to better prepare for new and emerging diseases. “The way we need to respond is a whole-of-society approach, and having the world consider this question is maybe the most important thing we could do,” said Rubin.
Weiss, who has been studying coronaviruses for her whole career, first shared a brief history of coronavirus, from discovery in the 1960s to the basic science that was key to understanding replication and infection of cells. During the SARS outbreak in 2002, researchers quickly identified a new coronavirus, SARS-CoV-1, as the infectious agent, she said.
After having known SARS-CoV-1 primarily as the cause of the common cold, Weiss said that researchers in her field were “shocked” that it could be causing such a deadly disease. “Until that day we had heard of not any pathogenic human coronaviruses,” she said. “Because of all we knew, we identified the virus quickly, and we started to make vaccines. But then the epidemic was gone in eight months, and people forgot about it.”
The story was similar with MERS, which emerged in 2012 and is still endemic to certain regions of the Middle East but, like SARS-CoV-1, had largely been forgotten on a global level. Now, with SARS-CoV-2 being the third coronavirus to emerge in the past 20 years, Weiss said “I was amazed and horrified that we didn’t do more to prepare.”
Weiss’ recommendations to prepare for the next pandemic include continued study of coronavirus biology, surveys of bat populations and other animal reservoirs that have the potential for spread, and the development of antiviral drugs, especially ones that work on all types of coronaviruses. “If another coronavirus emerges from animals, it will likely not be protected by the current vaccines, so we will need the antivirals as a quick response to whatever virus emerges,” she said.
Bushman, who has studied both HIV and coronavirus, discussed what characteristics give a virus pandemic potential, specifically efficient human-to-human spread and an animal reservoir. For SARS-CoV-2, efficient spread seems to be linked to its ability to spread asymptomatically; Bushman also mentioned that the coronavirus’ ability to only make a “single jump” could make them vulnerable to eradication, similar to what happened with SARS-CoV-1.
To prepare for the next pandemic, Bushman emphasized the importance of stockpiling personal protective equipment, continued research on antivirals, and the development of infrastructure for the new “game-changing” mRNA vaccine platform. “We need to build out this infrastructure so that if a new epidemic emerges, we can quickly make vaccines,” he said.
Rubin fielded questions from the audience and first asked Weiss what is known about when SARS-CoV-2 first emerged in humans. Weiss clarified that the complete picture of how SARS-CoV-1 emerged took some time, and that the question of how SARS-CoV-2 emerged is now being studied by a WHO team, with a report due soon. “Most people think that it came from a bat, probably through an intermediate host, and there’s good evidence that it was in China earlier in December,” she said.
On the topic of science communication and who the public should be listening to during a time of crisis, Bushman emphasized the importance of communicating uncertainty while reassuring the public that decisions are being made using the best available information at the time. “Subject area experts are who should be generating policies, but who should articulate that message? It should be anyone who can get through,” he said.
Responding to a question about variants, Bushman, whose lab is involved with sequencing SARS-CoV-2 samples from the Philadelphia area, emphasized the importance of continued genomic surveillance to figure out how the virus is changing and if changes to vaccines are necessary. “We’re in a race between the virus evolving and suppressing the virus with vaccines, masks, and social distancing,” he said. “We’re in America’s costliest war, with 500,000 people dead, and we’re now in the final battle, but it could go either way.”
Weiss agreed that continued vigilance is key, but is not as concerned about new variants changing the overall course of this pandemic. “RNA viruses change a lot, and more time means more changes, ones that allow it to replicate better. At some point we could reach an equilibrium where the virus is optimized for spread, and this could be the point where we should make a second vaccine or a booster,” she said.
Rubin asked what made this pandemic so difficult to manage and what types of government policies should be put in place to better address the next pandemic. Weiss said that the failure to address COVID-19 in the early stages was likely due to a combination of not quite believing how bad the pandemic would be and a lack of available funding and resources. Weiss also specifically highlighted the challenges in getting widespread testing up and running in the early days of the public health crisis.
“It’s hard for leadership under any circumstances to set aside resources for something that might possibly happen in the future when there are immediate demands,” said Bushman. “Going forward, we’ll have mRNA vaccine plants, we can stockpile PPE and do more antiviral research, but in the future sound and well-informed leadership will be key.”
The panelists also discussed how adverse events are analyzed in light of the recent pause in rollout for the AstraZeneca vaccine in Europe, how the pandemic has shaped the global response to other ongoing outbreaks like Ebola, how climate change will influence the spread of new infectious diseases, and COVID-19’s impact on how drugs and vaccines are tested in the future.
While revisiting the topics of booster shots, Bushman and Weiss shared their thoughts on how the rest of this pandemic might unfold. One extreme, said Bushman, is that COVID-19 is driven to “extinction” much like SARS-CoV-1. Alternatively, COVID-19 could become more like the flu, a virus that circulates and mutates enough to require a new vaccine. “That’s not the greatest because of the high morbidity and mortality but manageable and easier with the mRNA platform,” he said. “We’re really on the edge of both, which is why it’s important to keep up precautions. The enemy is starting to crack, and we need to keep up the pressure.”
Weiss, on the other hand, explained that, because coronaviruses don’t evolve as quickly as flu, there may be less of a chance it will become endemic and require regular boosters. “I may be optimistic, but, unless it keeps infecting vaccinated people and does immune escape mutations, in which case we would need a booster, I don’t see it as something chronic that we need to keep vaccinating. I don’t know for sure, but I would bet on maybe one more booster.”
A video of the virtual talk can be seen on Perry World House’s YouTube channel.
Frederic D. Bushman is the William Maul Measey Professor in Microbiology in the Department of Microbiology in the Perelman School of Medicine at the University of Pennsylvania.
Harvey Rubin is a professor in the Department of Medicine in Penn’s Perelman School of Medicine and a secondary appointment in the Department of Computer and Information Science in the School of Engineering and Applied Science.
Susan R. Weiss is a professor in the Department of Microbiology in Penn’s Perelman School of Medicine.
