This February, Keystone held a virtual conference that discussed SARS-CoV-2 transmissibility, immune response, and updates on vaccines and treatments. Here are some highlights of what we learned if you missed the chance to attend the Keystone eSymposia.
Transmissibility of COVID 19
Dr. Anthony Fauci kicked off the event with a keynote presentation providing a look at the general overview of COVID-19 in the United States. He stated that up to a third of all infections develop no symptoms, and 59% of all transmission comes from non-symptomatic or pre-symptomatic patients, which is why it has been so difficult to contain viral spread and perform accurate contact tracing.
Dr. Ben Cowling from the University of Hong Kong elaborated on that point, mentioning that COVID-19 is susceptible to super spreaders, where only 19% of the patients are responsible for 80% of the transmission. He also demonstrated the global nature of the disease and how an outbreak in Hong Kong caused an outbreak in Toronto at the start of the pandemic. One interesting point to note is that once Hong Kong schools reopened with mandatory masking, rhinovirus cases increased as it could easily penetrate masks. Additionally, the children had less immunity against rhinoviruses.
At this time, scientists still do not know how COVID-19 was transmitted from potentially bats to humans. However, they do know that many sarbecoviruses are poised to transfer to the human population. As noted by Dr. Ralph Baric from University of North Carolina at Chapel Hill, these types of viruses cause ARDS in mice. Additionally, it is estimated that 70% of all COVID-19 related deaths are attributed to respiratory failure. For this reason, mouse models of ARDS will likely become more prevalent and utilized in COVID-19 research.
Current Status of COVID-19 Vaccine and Treatment
Many pharmaceutical companies are doing impressive work to develop effective vaccines in an incredibly short amount of time.
Dr. Mark Esser, Vice President of AstraZeneca, demonstrated exactly that in his talk. He discussed the impressive work done by AstraZeneca & Oxford to develop a non-replicating adenovirus vectored vaccine that generated antibody levels similar to mild or asymptomatic COVID-19 infection. AstraZeneca is also working on a combined antibody candidate to treat COVID-19 with Vanderbilt University.
Dr. Kathleen Neuzil, from the University of Maryland, emphasized the importance of science, resources, and partnership on the development of novel vaccine candidates. Dr. Neuzil also stressed that the definitions used for the disease are critical for assessing the efficacy and are inconsistent across various vaccine trials. The FDA sets recommended efficacy at 50%, lower bound 30% in 30,000 sample size for vaccine development. The CDC encouraged enrollment of the older age groups, chronic conditions, and minorities, as they were disproportionately impacted by this devastating disease.