Daily COVID-19 Briefing: Saturday

Top news, reports and insights for today:

  1. Daily headline summaries for Saturday:
  • Despite widespread belief that the epidemic has moved past New York, over 47,000 people in New York, New Jersey and Connecticut tested positive over the last two weeks, over 13,000 in New York City alone. Essential workers (including medical personnel on the front lines) are still falling ill (New York Times)
  • Historian John Barry who wrote the definitive account of the “Spanish” influenza of 1918-19, said that President Trump has ignored the most important lesson of that tragedy: National leaders must tell the truth (CBS News)
  • New Harvard working paper reviews data on impact of weather, pollution and sunshine finding that warmer temperatures and moderate outdoor UV exposure may offer a modest reduction in the rate of viral transmission. They warn that weather alone will not be enough to fully contain the epidemic (Harvard University). 
  • As U.S. funnels billions toward companies rushing to create a COVID-19 vaccine before the election, Gail Van Norman, a professor of medical ethics at University of Washington said this week that “A new investigational drug that’s going into human trials has a 90% chance of failing” (Vanity Fair)
  1. New case update: Which state has the most newly reported daily COVID-19 cases? Maryland
     On Friday, 23,862 new COVID-19 cases were reported, a rise of 1.4% in total cumulative cases, now standing at 1.73 million. Last week, there were 143,328 reported new cases, a 9% increase, but the growth factor for the week was 0.92, indicating that overall, growth in cases is nearly flat. The bottom graph is something new. This figure compares daily new case reports per 100,000 people over the last week by state. This is a useful number to watch because it gives a rate of new cases which evens the playing field among states with very different population sizes. Also, numerous experts have said that new cases should be below 5 per day per 100,000 people before we can say that widespread transmission has stopped. As with other graphs I have made, this one shows states grouped by region in different colors. The vertical axis is daily new cases per 100,000 averaged over the last seven days. Looking at the data this way, the west is doing best, with no state reporting more than 6 daily cases per 100K, and 8 states with fewer than 5. Southern states are mixed with Florida, Kentucky, South Carolina, Texas and West Virginia with sub-5 new cases per day. Alabama, Mississippi and Virginia are all above 9. Four midwestern states saw 11 or more new cases per day per 100K last week: Iowa, Illinois, Minnesota and Nebraska. Only 1 northeastern state meets this benchmark (Vermont), the remaining states have seen 5 or more per 100,000 new cases. The fastest rate of growth in new cases came from my state, Maryland, which had 15.5 new cases per day per 100K. This comes after 2 consecutive days of more than 1,200 new cases on Thursday and Friday. By this metric, Maryland is a clear hotspot with more than 3 times the rate of new daily cases that are safe for reopening.
     The bottom line: Different metrics tell different stories about where the epidemic is going. Despite reassuring signs that things are slowing in the northeast, daily new case rates indicate there is a long way to go before the epidemic is under control in this region. Maryland, DC and Delaware continue to be in the cross-hairs of this disease.
  1. Big news: the first evidence that previous exposure to other coronaviruses may offer some partial immunity
    The top story today is one I am particularly excited about. I don’t want to overstate the case, but this may turn out to be an important turning point in solving the case of this disease. First, a little context. Two days ago, David Wallace-Wells, who is perhaps my favorite health journalist, posted a terrific article in New York Magazine, posing a good and simple question: Has the epidemic peaked? In that article, he reminds us that 3 weeks ago, the New York times broke a story about an internal CDC model, predicting 200,000 cases and 3,000 deaths a day by June 1. That’s tomorrow. We are now at about 20,000 cases and 950 deaths a day. The biggest question right now is why those models were so wrong? Even though it’s a positive development, that cases and deaths are not soaring as our models predicted, but it means we have some part of the bigger story wrong. Where is the equivalent of “dark matter” in cosmology that will make the math add up? Over the next week I will be covering several of the hypotheses that have gained traction to explain this, but first I am excited to tell you about one of them.
     A big idea: It’s possible that the rate of infections is slowing because some percentage of the population is partially immune to the new SARS-CoV-2 virus as a result of previous exposure to other coronaviruses. This idea has been sitting in the background waiting for some foundational scientific research start teasing this apart. The first compelling evidence came out in a paper published in the journal Cell on May 14 by Alba Grifoni and colleagues from the Center for Infectious Disease and Vaccine Research at the La Jolla Institute for Immunology in California. They looked at immune system response to SARS-CoV-2 in patients who were known to have had the disease and found more good evidence that the key cells in charge of spotting and attacking the virus were widely circulating in recovering patients, meaning that they were now immune to re-infection. Most interestingly, they also found that several of the primary immune system sentry cells capable of recognizing SARS-CoV-2 were present in about half of the people who were as yet unexposed to the new virus. This may be due to cross-immunity. That means previous exposure to one of the four coronaviruses that cause the common cold may have created a partial immune memory that allows some individuals to recognize and mount a response to the new virus. The study was small, using just 20 previous COVID-19 patients and 20 “unexposed” patients. Much more work needs to be done to determine whether the presence of immune cells that might recognize SARS-CoV-2 translates to actual partial or full immunity to the disease because of a prior common cold. One very cool feature of this study is that they used blood from samples taken years before COVID-19 started to make sure that the unexposed group really had not been infected.
     Bottom line: This is the first well-done peer-reviewed study that demonstrates it’s possible that COVID-19 cases and deaths are less than expected because some fraction of the population may be partially immune. That would be a game changer, because it would mean the threshold for herd immunity may be much closer. This doesn’t prove that half the population is partially immune, but its one piece of a very big and growing puzzle.

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