By Vivian Ho, Ph.D.
James A. Baker III Institute Chair in Health Economics
Kirstin R.W. Matthews, Ph.D.
Fellow in Science and Technology Policy
Heidi Russell, M.D., Ph.D.
Department of Pediatrics and Center for Medical Ethics and Health Policy
Baylor College of Medicine
Most of us have now endured two months of sheltering in place, yet The New York Times refers to our current situation regarding the spread of Covid-19 as a stubborn plateau. Still, the economic losses from lockdowns are causing many state leaders to continue relaxing restrictions on businesses and other public places. Experts from academia continue to worry that the U.S. lacks sufficient testing and contact tracing to reopen safely. Multiple reports by experts are out this week arguing that the government response regarding the amount of testing, contact tracing and vaccine development is insufficient.
Epidemiology and Treatment
On Friday May 8, data from the Covid Tracking Project indicated that the 7-day average number of daily new cases fell 11% to 25,895 compared to 29,119 a week earlier. Statistics for the country as a whole mask the realization that new hot spots are continually emerging. This New York Times graphic shows that daily new cases are steadily declining in the New York metro area, but new cases in the rest of the country continue to rise. The hotspots are in a mix of urban and rural areas. In Texas, one of the earliest states to relax lockdown restrictions, the 7-day average number of new cases rose 12% (from 778 to 868), although daily testing rose 15% during this time period.
The Institute for Health Metrics and Evaluation released new estimates last Monday, projecting 135,000 cumulative deaths in the U.S. by August 1. The IHME has updated their model since we last reported their predictions, including accounting for increased accuracy of case counts as testing rises, as well as a detailed measure of social distancing based on data from multiple sources. The model is the most sophisticated that we have seen, although the IHME takes the approach of predicting cases and deaths assuming that states maintain their current lockdown policies (announced by April 28) all the way through early August.
The IHME therefore provides optimistic estimates, because it does not account for future relaxation of states’ restrictions which are likely to occur. For example, the model accounts for Texas reopening businesses to 25% capacity on May 4, but does not account for a move to 50% capacity that the governor may allow in mid-May. And because New York Gov. Cuomo has not formally announced any dates for easing restrictions, the model presents predictions assuming the state is on full lockdown through early August. Therefore, the model predicts three infections per day in New York and 865 per day in Texas on August 4. While these scenarios are unlikely to occur, they do illustrate the significant effect that social distancing has on the spread of the virus.
Scientists are steadily increasing their understanding of the virus’ biology and pathology. This week the CDC added additional Covid-19 symptoms including gastrointestinal symptoms, chills and sore throat. In addition, researchers conducting lab experiments in the Netherlands determined that the SARS-CoV-2 virus (the virus that causes Covid-19) can infect cells in the gut using the same ACE2 receptor it targets in the lung. These results suggest that the virus could also cause gastro-intestinal infections, and fecal-oral transmission could be possible. The ACE2 receptor is quite common and found on numerous cell types, so other modes of transmission could be possible. However, at this time the most severe cases seem to be linked to respiratory illnesses.
If one obtains immunity to the SARS-CoV-2 virus, we still don’t know how long it lasts. The preeminent scientific journal Nature released an excellent series of infographics this week. The series walks the reader through how we develop immunity and the biology behind the four types of vaccines currently being developed: virus-based (using a weakened or dead virus), viral vector-based (using another virus that is engineered with SARS-CoV-2 DNA), nucleic acid (using DNA or RNA), or protein-based (using a molecule on the surface of the virus). The vaccine from Oxford University, discussed in last week’s blog, is viral vector-based, while Moderna and Inovio’s vaccines are nucleic acid based.
We mentioned previously that the FDA has been approving Covid-19 tests under the Emergency Use Authorization (EUA) in an effort to speed up test availability. However, The Wall Street Journal reported that 160 antibody tests for Covid-19 entered the U.S. without any FDA scrutiny on March 16, because the FDA felt it was most important to get them to the public quickly. Scientists subsequently determined that only 14 of these tests delivered accurate results, and only three delivered consistently accurate results. Now the FDA will require antibody tests to obtain an EUA. To do so, the tests must be able to correctly detect the coronavirus antibody in 90% of tests and avoid false positive results in 95% of cases.
Meanwhile, we are encouraged that pharmaceutical company Roche Holding received an EUA for its antibody test. Roche says its test is 100% accurate in identifying Covid-19 antibodies, and it yields a false positive result in only 2 of every 1,000 tests. The tests will be manufactured in Germany, and the company aims to produce in the high double-digit millions per month by June.
We continue to be concerned about the lack of sufficient testing and contact tracers across the country, particularly since Harvard’s Institute for Global Health concludes that the U.S. needs to be conducting 900,000 tests a day in order to control the pandemic. The Institute previously recommended 500,000 tests a day, but they found that the outbreak is worse than projected earlier. The Institute found that Georgia, which has some of the laxest restrictions in the country, is testing at 67% below its recommended rate. Texas and Florida, which have also eased more restrictions than most states, have testing rates which are roughly one-third below recommended rates.
Reporters have written that the Trump administration held back a 17-page report prepared by the CDC that was to be released several days ago. Reporters obtained a copy of the document, which provides step-by-step advice to local authorities on how and when to reopen restaurants and other public places. For example, the report recommends that communities of faith limit gatherings to those that can maintain social distancing and consider video streaming or drive-in options for vulnerable populations. White House coronavirus adviser Dr. Deborah Birx stated that the guidelines are still being edited, and that they needed simplification. Nevertheless, a CDC official said that agency scientists were told the guidance “would never see the light of day.”
Two Yale economists recommend substantially higher reimbursement for coronavirus tests, along with robust government action to increase test availability. They reason that reduced economic activity due to the pandemic has likely reached $100 billion per week. They further note that lab tests (and PPE) yield significant positive externalities to the economy, because they are instrumental in slowing disease spread and perhaps eventually eradicating the coronavirus. That is, reimbursement for lab tests should be commensurate with the benefit they will yield in reopening the economy more quickly. The federal relief package allotting $25 billion to facilitate and expand Covid-19 tracking is therefore far too low. Potential suppliers of test kits need greater economic incentives, particularly since they are being asked to re-tool and expand production for a product that could see a rapid drop in demand when antivirals or a vaccine becomes available. The economists recommend that the federal government should set a fee schedule for Covid-19 testing that applies to all payers, and the payment should likely be double the current $100 amount paid by Medicare.
Four prominent economists are recommending that the federal government create a Covid-19 vaccine Advance Market Commitment (AMC) to promote vaccine development. Under the AMC, the government would guarantee that it would spend $70 billion on vaccine discovery and manufacturing capacity. The guarantee would include $100 per person for the first 300 million vaccinated. They seek to encourage 15 to 20 vaccine candidates. The AMC would guarantee firms partial reimbursement for production capacity built or repurposed, so that the manufacturers have “skin in the game” when building capacity.
A Washington Post article notes that state and local health departments do not publish the occupations of individuals who test positive, even though this information would be invaluable in the absence of robust contact tracing. The same article quotes an assistant medical director who found recent positive results from a grocery store worker, a day-care employee, and a housekeeper; all had contact with a Covid-19-positive person at work. The reporter observes that the pandemic is infecting those with limited ability to social distance, who are afraid to lose their jobs. Although the Families First Coronavirus Act provides paid sick leave for many workers affected by Covid-19, it excludes companies that employ more than 500 people, as well as gig workers. The federal government should pass legislation providing paid sick leave for these lower-wage workers, which would reduce their desire to continue working if they experience Covid-19 symptoms.
In the coming week, we will be closely watching statistics on testing availability and number of new positive cases, particularly in states that have begun lifting restrictions. We are surprised that we have not heard more about the contact tracing app that is being designed by Apple and Google, although it is expected to be ready this month. We hope to hear more encouraging news about states increasing their number of contact tracers as well.