COVID-19 Weekly Newsletter: Researchers Study Dining Risks, Asymptomatic Transmission
A recent report from the Centers for Disease Control and Prevention (CDC) revealed that dining out carries heightened risk of COVID-19 transmission, but did not reveal a similar heightened risk related to travel. Studies continue to demonstrate that children and other asymptomatic carriers are still likely capable of transmitting COVID-19 at rates comparable to those displaying symptoms. As cases rise in the U.S., government, academic, and pharmaceutical stakeholders continue efforts to develop, validate, and prepare to distribute an effective COVID-19 vaccine.
After Senate Republicans failed to pass a new COVID-19 relief package last week, it has become increasingly likely that Congress will not pass additional COVID-19 legislation before the election. Instead, legislators are turning their attention to funding legislation to ensure the government remains operational following the end of the fiscal year on September 30.
Travel & Restaurants
A recent report from the CDC showed increased risk of transmission of COVID-19 from dining out and cautioned patrons from going. The CDC ranked eating out from lowest to highest risk based upon the level of interaction and time spent at the establishment, determining that take-out, delivery, and curb-side pick up presented the lowest risk. On-site dining where seating capacity is not limited and socially distant table spacing is not conducted carried the highest risk of transmission. The restaurant industry responded by noting that many factors were not taken into consideration — such as size of establishment, length of time of interaction between customer and server, and variable state dining restrictions. In contrast, airplane travel has surprisingly not been found to be the cause of as many new cases as thought. One explanation for this may be due to the air in modern aircrafts being replaced with new air every two to three minutes, with air filters that trap 99.9% of particles.
U.S. Cases & Response
Though the Trump administration has given hope that a coronavirus vaccine could be ready for distribution by mid-October, CDC Director Dr. Robert Redfield thinks otherwise. In a Senate hearing this past Wednesday, Redfield explained the effectiveness of any vaccine will not be known until spring and, for now, the only known, effective protective barrier is a mask. Recent surveys show Americans believe the vaccine is being developed too quickly and a significant number of them wouldn’t get vaccinated as a result. The U.S. holds only 4% of the world’s population but has 25% of the world’s coronavirus cases.
Vaccine Trial Restarted in U.K., Still Paused in U.S.
AstraZeneca’s Phase 3 COVID-19 vaccine clinical trials have restarted in the U.K. following a voluntary pause when a patient was hospitalized after being injected with the candidate vaccine. In the U.S., the vaccine trial is still paused pending Food & Drug Administration (FDA) and safety panel review. Director of the National Institute of Allergy and Infection Disease Dr. Anthony Fauci has stated it is “just a matter of time” before the trial resumes and “it would be unusual to completely stop a trial on the basis of one adverse event.”
States Plan to Independently Evaluate Vaccine Safety
With concerns of political pressure unduly influencing FDA’s ability to review the safety and efficacy of vaccine candidates as part of the approval process, several U.S. states — Arizona, California, Colorado, Georgia, Michigan, New York, Oklahoma, Oregon and West Virginia, along with the District of Columbia — have indicated they require an independent review of the data before distribution of a vaccine would occur. This approach could disrupt vaccination plans and ultimately cost lives, but it resembles the variable pandemic responses that have been observed among states. States are trying to be reassured that two independent bodies, the Advisory Committee on Immunization Practices and FDA’s Vaccines and Regulated Biological Products Advisory Committee, will help ensure any vaccine has been properly evaluated and vetted before authorized. These bodies, which advise the CDC and FDA, would provide such review through public meetings where any political interference should be known.
While Kids May Be Less Affected by SARS-CoV-2 Than Adults, They Still Are Effective Spreaders of the Disease
Children seem to be less affected by SARS-CoV-2 than adults. The number of pediatric COVID-19 patients is lower, as is the proportion of pediatric cases progressing to severe stages. If kids don’t get sick as much, does it mean they don’t spread the disease as much? One of the defining features of the SARS-CoV-2 infection that turned it into a global pandemic is the possibility of the virus transmission from asymptomatic virus carriers, as explored in studies published in Nature Medicine and by the National Center for Biotechnology Information. For this reason, the role of children in the spread of the virus is an important question that, at the moment, remains open. One recent study determined that the viral SARS-CoV-2 RNA load did not differ between pediatric and adult patients 5 days post symptoms onset, indicating similar transmission capacity at least in those individuals who had started exhibiting symptoms. The age of participants in the study (0-82 years old) showed no effect on their viral load. In a separate study , the viral load was shown to be similar in symptomatic vs asymptomatic patients — in a group of subjects with the median age of 25 years old. This means that even without symptoms, young viral carriers can expose others to high viral loads of SARS-CoV-2. For influenza, the severity of contracted disease had previously been shown to directly correlate with the level of the viral load exposure. For SARS-CoV-2, no published study has definitively quantified the time-course and decisive factors of infectivity yet, but the viral load detected in COVID-19 patients has been shown to be predictive of mortality of those patients.
Taken together, the evidence published to date supports the need for continued adherence to such public-health measures as social distancing, mask-wearing, hand-washing and, whenever possible, tracking and isolation of confirmed cases, be it for children or adults. And with the school year now underway, it is important for students to continue to be vigilant.
Preparing Population for a SARS-CoV-2 Vaccine
Social scientists have long realized that understanding, respecting, and taking into account human perceptions, preferences, and subjective attitudes would be critical in ensuring wide acceptance of any proposed solutions to the current pandemic, which in turn is a prerequisite for the effectiveness of any public health measures in curbing the crisis. Earlier this spring, several leading academic institutions formed a Working Group on Readying Populations for COVID-19 Vaccine. The Working Group’s recommendations have now been published. The Working Group recognized that there are a number of ongoing challenges that complicate the development of an appropriate public health response, such as:
existing scientific and technology-platform uncertainties surrounding the biology of the virus and immune responses to it.
inconsistent or incomplete information communicated publicly about vaccines’ safety and effectiveness.
social challenges unrelated or tangential to COVID-19 but hindering a unified public response and recovery.
Accordingly, the Working Group’s recommendations highlight the following areas that would be key to a successful strategy:
allocating resources and engaging communities in discussion of priorities and solutions.
developing capacity for local vaccine deployment.
communicating thoughtfully and speaking meaningfully.
Antibodies to SARS-CoV-2 in Medical Personnel Decline Markedly Over 60 days
A recent study examined the time-course of antibodies to SARS-CoV-2 in the blood of medical personnel. Over 200 nurses, physicians, and other medical professionals joined the study. Of these, only 19 had detectable antibodies at baseline in April 2020. By June, less than a half of these participants had detectable antibodies. The level at which antibodies circulating in the blood confer immunity has not yet been established, so the decline cannot yet be equated with a loss of immunity. This outcome does suggest, however, that estimating the spread of infection in the general population based on antibody test results would underestimate the total number of prior SARS-CoV-2 infections due to the rapid decline of antibodies in as many as half of the cases. Another informative finding from this study is that the declining trend is essentially the same for both symptomatic and asymptomatic subjects who tested positive for SARS-Co-V-2 antibodies at the baseline visit.