Author: Will Humble

Here is Dr. Gerald’s latest weekly epidemiology and hospital capacity report. Here is his narrative summary (below) and here’s his full weekly report.

 Cases and hospitalizations continue to increase state-wide with the more rural, previously spared counties leading the charge. Pima County saw a second straight week with a fairly large increase. Last week’s increase was due in part to a confirmed outbreak in a correctional facility. Even so, there is ample evidence of broader community-level transmission.

While not yet a crisis, hospitals capacity is at the point where Covid and non-Covid occupancy is placing a noticeable strain on personnel and resources.

More than 90% of Mild to Moderate COVID-19 Patients have Strong Antibody Response

Most people with mild-to-moderate COVID-19 produce antibodies that can fight off the infection that remain at similar levels in the body for at least 5 months, suggests research carried out at Icahn School of Medicine at Mount Sinai in New York.

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Regeneron’s Two-Antibody COVID-19 Treatment “Cocktail” Reduces Viral Load

REGN-COV2, has met its primary endpoint of significantly reducing viral load and medical visits in ambulatory adults with COVID-19. However, the company is reviewing a possible change of dosages in the study after finding no significant difference in efficacy between the high and low doses of the treatment.

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Facial Masking for Covid-19 — Potential for “Variolation” as We Await a Vaccine

M. Gandhi and G.W. Rutherford N Engl J Med 2020;383:e101

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Evaluating and Deploying Covid-19 Vaccines — The Importance of Transparency, Scientific Integrity, and Public Trust

J.L. Schwartz N Engl J Med 2020;383:1703-1705

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CDC Releases Two New MMWRs

The first release describes an investigation of a university’s men’s and women’s soccer team where 17 COVID-19 cases were identified. Lax social distancing and mask use during social gatherings were thought to contribute to the spread.

The second release describes results from the Data Foundation’s COVID Impact Survey. Self-reported adherence to COVID-19 mitigation measures was lowest in the 18-29 age group, while those 60 years or older reported the highest adherence.

COVID-19 Mortality Risk in Down Syndrome: Results from a Cohort Study of 8 Million Adults

In this study, researchers compared risk factor for death from COVID-19 by doing an analysis of individual-level data in a cohort study of 8 million adults in the U.K.  Their primary outcome of interest was COVID-19 mortality within 28 days of a confirmed SARS-CoV-2 infection.

After adjusting for age and sex, ethnicity, BMI, care home residency, congenital heart disease, and a range of other comorbid conditions the researchers, found that folks with Down Syndrome had a 10 times higher risk of death if diagnosed with COVID-19.

As you interpret the study, keep in mind this this result is after age adjustment. Far and away the dominant risk factor for dying from COVID-19 is age, even among those with Down syndrome. Think of it this way. A 26-year-old man with Down syndrome starts out with a case fatality rate of that of a typical 26 year-old. You’d then factor in an additional 10-fold increased risk. 

A 26-year-old typical male would have an approximately 1/100,000 case fatality ratio (CFR) from COVID-19. A 26-year-old person with DS would then have a CFR of 1/10,000.

Compare that however, to a pair of 50-year-old males. The CFR starts out at approximately a 1/10,000. The peer with Down’s syndrome would have a CFR of 1/1,000. 

For perspective, an 80-year-old male has a CFR of about 1/200. Here’s the article where I retrieved the case fatality ratios.

In a normal clinical trial for a vaccine, a person in the vaccination group is given the vaccine while those in the placebo group get something like a saline injection. Both groups then go out to the community. Observations are made over time in both the vaccine and placebo groups to determine whether the vaccine protects people from infection.

There’s another kind of trial which speeds things up a lot called a “Challenge Trial”.  That’s when a person is vaccinated and then is later intentionally exposed to the virus to see whether they get sick.

There are obviously some ethical questions about challenge trials but they have some real advantages as well because they can speed up getting results by weeks or even months. You get cleaner data as well because you are sure about the exposure. So, in a public health emergency – when people are losing their lives every day- should we be using Challenge Trials to speed things up? After all, you know for sure that people are dying every day and that if you can speed up the trial, you’ll be able to save many lives by accelerating the trials.

Persons in Challenge Trials are volunteers. They are also done after  the Phase II trial has been completed so you have at least some information about the safety.

On the other hand, you may need to challenge persons that got the placebo (not the vaccine)…  posing clear ethical questions.  An alternative could be to challenge just the vaccine group (not the placebo group) with various doses of challenge virus and look to see whether there’s a dose-response. That might be a way around exposing the placebo group.

Anyway- take a look at this essay about Challenge Trials in Medscape this week.  Interesting short read.

Here’s a link to Dr. Gerald’s latest Epi report for Arizona. Below is his introductory paragraph. You can go to the full weekly report at this link.

For the week ending October 25th, 7221 new Covid-19 cases were diagnosed in Arizona (Figure 1). This represents a 19% increase from last week’s revised tally of 6064 cases. Reporting delays continue to be minimal.

Accordingly, last week’s tally of 5779 new cases was only upwardly revised by 5% (285 cases) this week. Some of this backfill was also attributable to moving this report earlier in the week. Case counts continue to increase among all age groups (Figure 2 following page). Rising case counts warrant reappraisal of government policies as well as individuals’ adherence with face masks, physical distancing, and hand hygiene practices. Current transmission levels are just shy of those observed during the first week of June when 8239 cases were diagnosed. A mere 3 weeks later, Arizona’s case count reached a peak of 27796 cases.

Given the possibility of exponential growth, current conditions could deteriorate rapidly.

CDC released new guidance strongly recommending face masks be worn by all passengers and personnel while on public transportation (including airplanes, ships, ferries, trains, subways, buses, taxis, and ride-shares) and at transportation hubs (such as airports, bus or ferry terminals, train stations, and seaports).