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Dr. Gerald just published this week’s AZ epidemiology and hospital capacity report, and the results are alarming. Those of you that read this blog seldom see me using that kind of language (at least since June and July) but there’s no other way to say it. This week’s report feels a lot like early June.

We’re now entering exponential growth of cases especially in the 15 to 24 year-old group but also among 25-64 year-olds. As Dr. Gerald says in his report this week:

“We are now entering a crisis, one in which we have little time to walk-back from. While hospitals still have capacity to care for critically ill patients, we are nearing the point at which noticeable shortages of personnel and resources are going to emerge. owing to rapidly increasing case counts and the lag between case identification and hospitalizations. If this “surge” is not quickly addressed, new Covid-19 cases will overwhelm our capacity to provide optimal hospital care within a matter of weeks.”

Community-driven transmission has surpassed the rates we experienced during the second week of June when 13,000 cases were diagnosed. At current transmission levels, Arizona is not far from exceeding the weekly cases we had just before the state authorized using Crisis Standards of Hospital Care in early July.

We’re also are seeing significant viral amplification in rural areas (that generally have no mask mandates in place) with Graham, Gila, Coconino, Yuma, and Navajo counties having higher than average per capita rates.

Hospital admissions and eroding capacity are lagging the case rates just as we saw in June and July. The percentage of ICU beds occupied by patients with Covid-19 has increased from a low of 6.2% on September 13th to 18.4% on November 10th.

The current hospital surge differs from the one in June in that Covid-19 infections have shifted towards younger patients who are less likely to require hospital and ICU care. Also, better infection control practices and staff testing capacity in long-term care settings have led to proportionately fewer cases among the most vulnerable long-term care facility residents (Figure 8 in Dr. Gerald’s report shows the Pima County data).

Those factors, along with improving treatments, more experienced providers, and greater testing accessibility have led to a 23% reduction in hospitalizations and a 45% reduction in ICU cases for the same number of Covid-19 diagnoses (Figure 9). However, when rising community-transmission spills over into long-term care settings, admissions will rise more quickly. Arizona hospitals also have less reserve capacity now than when hospital occupancy was lower this summer.

The return of part-time residents, a backlog of elective procedures, and non-Covid respiratory illnesses also mean that hospitals will reach capacity sooner than they did this summer. If that happens, Arizona can expect less external staffing assistance this time since many other states are experiencing their own hospital capacity crises.

WHAT CAN BE DONE?

Face Coverings

For the last several weeks we’ve been calling for a statewide face covering mandate. Face coverings are increasingly recognized as the highest return on investment intervention to slow the spread of the SARS CoV2 virus (besides vaccines). Evidence from the National Academies of Medicine and Science demonstrated this effectiveness. More compelling results have been shown in a recent Systematic Review of studies in The Lancet.  It’s past time for Arizona to implement a sensible statewide face covering mandate similar to the one implemented by Utah’s governor last weekend.

Mitigation Measures in Bars and Restaurants

A recent model reported in Nature, shows that many infections are likely  coming from bars and restaurants. Indeed, in Arizona the combination of allowing local jurisdictions to implement face covering ordinances and temporarily closing bars and scaling back restaurant capacity to 50% had a dramatic effect on the spread of the virus.

The best thing we can do as a state right now is to learn from last summer’s lessons and significantly reduce the number of people allowed in bars and restaurants at one time. We know these mitigation strategies work and they are our best option for reducing spread and ensuring that our healthcare system will be able to provide high-level care.

The enhanced mitigation measures will need to be accompanied by better compliance and enforcement than we currently have in place. The governor  should consider an executive order to give enhanced enforcement authority to county health departments so they can get bars and restaurants that aren’t following the mitigation measures back into compliance. Counties will also need CARES Act funds to finance the effort.

Personal Responsibility

As we press into the holiday season, the urge to gather socially with friends and family will be tempting, especially given the stress of 2020. However, it’s important that we think through the ramifications of our decisions. Decisions we make through November and December could be with us for months to come and could impact how we visit loved ones in hospitals or long term care facilities, whether our kids can return to school as well as the level of care we receive from our healthcare system.

Failure to act now in proactive ways will likely result in completely closing bars, nightclubs, schools, hospitals and visitations in long-term care facilities in early December when hospital capacity is exceeded and Crisis Standards of Care are again authorized.

Age specific mortality and immunity patterns of SARS CoV2

In this study researchers explored the case fatality ratio for COVID-19 among all age ranges. They found that mortality is lowest among kids 5-9 years old and that there’s a log-linear increase by age among individuals over 30. They conclude that age and risks from living in a nursing home explains some (but not all) of the differences between countries when it comes to infection-fatality ratios.

“Among the 45 countries included in our analysis, we estimate approximately 5% of these populations had been infected by the 1st of September 2020, with much higher transmission likely to have occurred in a number of Latin American countries. This simple modelling framework can help countries assess the progression of the pandemic and can be applied wherever reliable age-specific death data exists.”

MMWR: Transmission of COVID-19 in Households 

A new MMWR from the CDC describes COVID-19 transmissions in households. The report found that there was a 53% secondary infection rate in households. The results reinforce the idea that folks should self-isolate and wear masks in shared household spaces.

SARS-CoV-2 Neutralizing Antibody LY-CoV555 in Outpatients with Covid-19

In a phase 2 trial, outpatients with Covid-19 who received a single infusion of a 2800-mg dose of the neutralizing antibody had a greater reduction in viral load compared to people who got the placebo. Hospitalization was less frequent among antibody-treated patients too (1.6% vs. 6.3%). Here’s the article.

New and Updated MMWR: Characteristics of Symptomatic Women and Infants Following COVID-19 Infection in Pregnancy

In a new MMWR, authors describe pregnancy outcomes among women with COVID-19 infection. Through the Surveillance for Emerging Threats to Mothers and Babies Network, 16 jurisdictions collected information on pregnancy and infant outcomes among 5,252 women with COVID-19 infection reported during March 29–Oct. 14, 2020.

Both preterm birth and adverse infant outcomes were observed at higher rates among women with COVID-19 infection. Additionally, CDC provided an update on characteristics of symptomatic women of reproductive age with COVID-19 infection.

Pfizer announced on Monday that an early analysis of its coronavirus vaccine trial suggested the vaccine was robustly effective in preventing Covid-19. The announcement didn’t come with many details so I don’t have many details to share except the following:

The Phase III Trial was conducted in the U.S. and has enrolled about 44,000 volunteers. About half of the participants were in the placebo group and about half were in the group that got the vaccine (with a booster a month later). The company said that almost all of the 94 persons in the trial that ended up contracting COVID-19 were in the placebo group. Statistically speaking, they said that the Phase III data (which has not been disclosed) suggests that the vaccine is 90% effective at preventing COVID-19. They also said that no serious adverse events were identified.

A couple of cautionary notes are that these results haven’t been released or published in a peer-reviewed journal article. Also, many of the participants in the Phase III trial haven’t been followed up for even a full 60 days yet (important for identifying adverse events).

There are 11 vaccines in late Phase III trials right now including 4 in the U.S. This Pfizer vaccine as well as Moderna’s candidate use a new Messenger RNA technology that has never before been used to create a vaccine. Both Moderna and Pfizer expect to submit full Phase III trial data in the coming weeks.

Here’s a link to one of my previous blog posts that discusses how vaccines are tested and approved.

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.