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Testing continues to be a problem in Arizona. Demand far outstrips the supply of available tests and the time it takes to get samples back from the lab is too slow. Reports from the field suggest that samples sent to the Sonora Quest labs are coming back between 7-14 days after specimen collection.

That kind of turn around time doesn’t provide actionable information to persons that get tested because they don’t know their status in time and they are far less likely to go into isolation if they’re not sure whether or not they really have COVID. 

In addition, the county health departments get the data back from the lab too late to do an effective case investigation and conduct contact tracing. The case may have already recovered and infected their roommates, family members, co-workers and community persons. 

Business owners (especially assisted living and skilled nursing facilities) are also behind the 8-ball because the data on their employees comes back so late that there’s no real actionable information- and they’re unable to make evidence based decisions about who is safe to attend work.

Fortunately the governor and health director have committed to increasing statewide testing capacity to 35,000 tests per day by July 31 (2-weeks).  Great that they set a discrete goal – but I would have loved to see a SMART Goal something like this:

By July 31, Arizona will be testing 35,000 persons per day with 90% of tests returned to the patient within 72 hours. I  addition, I think we really need to have the ADHS dashboard track sample turn-around times. After all, What Gets Measured Gets Done.

Editorial Note: The governor has yet to use public health emergency authority to require assisted living and skilled nursing facilities to routinely test their staff in order to prevent the virus from leaking into these congregate settings. Folks in these facilities continue to be a very large portion of the hospital patient census, and better testing and infection control in these settings could improve available hospital capacity and save lives. 

Last week the FDA has granted emergency use authorization for pooled coronavirus testing for Covid-19. The approach involves combining samples from multiple people, which are only tested individually if the batch comes back positive. Perhaps this approach, along with increased use of antigen testing and requiring routine staff testing in congregate settings can help us out with our hospital capacity issues.

However, none of these things will work if the turn around times for samples continue to be insufficient.

School season is rapidly approaching. A huge public health policy question out there is “how do we decide when school can start this Fall (if at all) and under what circumstances”?  Thus far, the governor has been talking about when schools would be allowed to open for in-person instruction rather than under what circumstances.

A couple of weeks ago, he postponed the start of school until August 17, a date that he described as “aspirational”.  Setting a date for school to start is arbitrary if it’s not linked with evidence-based public health metrics. It makes a lot more sense to tie school openings to evidence-based performance criteria.

There are 2 categories of criteria that should be used to make the school opening decision:

• The quality of school district mitigation plans & their ability to execute those plans with fidelity; and

• Evidence-based criteria that measure community transmission. 

Both these factors should be in place before considering setting a date for in-person instruction to begin.

While many school districts have quality mitigation plans to lower the risk of spread, community transmission is too high right now to adequately protect kids and staff- even if they have good plans.  Testing capacity is inadequate, sample turn-around times are insufficient, contact tracers get tardy data, public health laws are inadequate and unenforced, and testing & infection control are inadequate in care homes.  All the above issues are fueling community spread and need to be improved before schools open this Fall.  But, how would we measure success?

Fortunately, we can come up with evidence-based performance measures to help determine whether community transmission is low enough warrant opening our K-12 schools for in person instruction.

Let’s explore the possibilities.  Consider the 4 bullets below as the criteria that would need to be met to set a date to open schools for in-person instruction:

• A 30-day reduction in the number of new COVID cases in the community measured by a 7-day moving average;

• A community percent positive rate of less than 5% for 2-weeks measured by a 7 day moving average;

• Eighty percent of case and contact tracing investigations completed within 96 hours of sample collection over a 21 day period; and

• Community hospitals open for elective procedures.

When a community meets all these criteria, the district could be free to set a date for in-person instruction (if their county health department has validated their mitigation plans).  County personnel could conduct periodic on-site validation of school’s mitigation plans.  If community transmission rebounds and the above criteria are no longer met, then districts would need to suspend in-person instruction.

Another advantage to this evidence-based performance criteria approach is that members of a community would have a common goal to work toward- as nearly everybody agrees that in-person school instruction is important and worthy of trying to achieve.  Having measurable criteria in place to make that happen can build additional community motivation to achieve and maintain the important mitigation measures that reduce transmission of the virus.

We just received Dr. Gerald’s latest COVID analysis. For the first time in many weeks there are some encouraging signs. New cases have stabilized (albeit at a very high level). Likewise, the percent positive drifted downward slightly in the last week. Hospitalizations for COVID also stabilized (although at extremely high levels). Take home for this week is at least things didn’t get worse- so by that standard- things got a little better.

For the week ending July 12th, Arizona recorded 15,160 new Covid-19 cases. However, this undercounts the actual number of new cases because as 50% of PCR results take more than 5 days to be reported. For example, last week’s tally has been revised up by 32% because of slow turn-around times.

The percent of patients testing positive drifted down slightly – going from 23% the week ending July 5 to 19% the week ending July 12. A declining test positive percentage in the face of declining testing capacity lends additional evidence that viral transmission is slowing in response to the public’s adherence with new face mask ordinances, additional business restrictions, and other recommended health behaviors.

On the hospitalization front, total Covid-19 hospitalization increased 311% from 1093 to 4487 occupied beds between May 22 and July 13. The good news is that In the last week total Covid-19 hospitalizations increased only 1% (going from 4384 to 4410 occupied beds). If the trend continues hospitals should see stabilizing or declining admissions over the coming weeks.

While these leading and contemporary indicators are stabilizing- no such luck for deaths. The week ending July 5th is now the week with the largest number of Covid-19 deaths (339). Because deaths lag new cases by about 2 weeks, deaths will continue to increase for the next week or two before moderating or declining.

The Arizona Hospital and Healthcare Association recently asked the ADHS for some regulatory relief so that their member hospitals can more effectively respond to the ongoing surge of COVID patients.

AzHHA asked for waivers that would allow the transport of patients in private vehicles, let hospitals send some emergency room patients to urgent care, and allow them to put adult and pediatric patients in the same room among other things. 

The ADHS responded later in the week and agreed to waive some but not all of the requests. Here’s the letter from ADHS and here’s the administrative order.

A mathematical model reveals the influence of population heterogeneity on herd immunity to SARS-CoV-2

DOI: 10.1126/science.abc6810

Population heterogeneity can significantly impact disease-induced immunity as the proportion infected in groups with the highest contact rates is greater than in groups with low contact rates.

We estimate that if R0 = 2.5 in an age-structured community with mixing rates fitted to social activity then the disease-induced herd immunity level can be around 43%, which is substantially less than the classical herd immunity level of 60% obtained through homogeneous immunization of the population.

Our estimates should be interpreted as an illustration of how population heterogeneity affects herd immunity, rather than an exact value or even a best estimate.

The ADHS is implementing a new Surge Staffing Initiative. Similar to the Surge Line, this program will try to stabilize community hospital hot spots to deal with the ongoing surge of patients. It may also provide some relief for nursing staff. 

The initiative allows hospitals to apply to receive out-of-state nurses. The nurses will be deployed for a 6 week period for up to 20% of their licensed capacity at no cost.  The Arizona Surge Line staff will make the deployment decisions. 

Hospitals received the application forms this week. Here’s an example of the application questions and attestations.  

https://www.nejm.org/doi/full/10.1056/NEJMoa2022483

BACKGROUND

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in late 2019 and spread globally, prompting an international effort to accelerate development of a vaccine. The candidate vaccine mRNA-1273 encodes the stabilized prefusion SARS-CoV-2 spike protein.

METHODS

We conducted a phase 1, dose-escalation, open-label trial including 45 healthy adults, 18 to 55 years of age, who received two vaccinations, 28 days apart, with mRNA-1273 in a dose of 25 μg, 100 μg, or 250 μg. There were 15 participants in each dose group.

RESULTS

After the first vaccination, antibody responses were higher with higher dose (day 29 enzyme-linked immunosorbent assay anti–S-2P antibody geometric mean titer [GMT], 40,227 in the 25-μg group, 109,209 in the 100-μg group, and 213,526 in the 250-μg group). After the second vaccination, the titers increased (day 57 GMT, 299,751, 782,719, and 1,192,154, respectively).

After the second vaccination, serum-neutralizing activity was detected by two methods in all participants evaluated, with values generally similar to those in the upper half of the distribution of a panel of control convalescent serum specimens. Solicited adverse events that occurred in more than half the participants included fatigue, chills, headache, myalgia, and pain at the injection site. Systemic adverse events were more common after the second vaccination, particularly with the highest dose, and three participants (21%) in the 250-μg dose group reported one or more severe adverse events.

CONCLUSIONS

The mRNA-1273 vaccine induced anti–SARS-CoV-2 immune responses in all participants, and no trial-limiting safety concerns were identified. These findings support further development of this vaccine. (Funded by the National Institute of Allergy and Infectious Diseases and others; mRNA-1273 ClinicalTrials.gov number, NCT04283461. opens in new tab).

The most talented scientists around the world are busy developing vaccines for the virus that causes COVID-19. There have been some encouraging developments in recent weeks. There are 18 vaccine candidates under clinical evaluation world wide right  now.  The one that’s the furthest along is an 8,000 person Phase III trial in the UK.

There aren’t any Phase III trials underway in the US yet, but Moderna vaccine expects to go to Phase III at the end of the month or the beginning of August. Moderna’s vaccine had positive early results, developing antibodies against the virus. Another Covid-19 vaccine candidate being developed by Pfizer and a  German company called BioNTech had positive data in early tests.  Their preliminary findings last week (in this pre-print) developed antibodies and the vaccine was well tolerated.  The company said it remains on track to be able to deliver approximately 500 million doses per year, and possibly up to one billion doses per year, beginning in 2021 from both its internal U.S. manufacturing site and a strategic collaboration with Lonza.

Inovio has stated that they have promising early data (Phase I). In that Phase I trial 94% of people developed a specific immune response in six weeks after receiving two doses of the vaccine INO-4800 and by eight weeks, the vaccine regimen was found to be safe and well-tolerated with no serious reactions.

There have several areas of the state that have had a dearth of COVID testing opportunities because community testing has been lacking or absent.  Examples tend to be in areas with lower average incomes like in Maryvale and South Phoenix. Looks like those areas will be getting some relief. 

Last week the ASU Biodesign Institute and the ADHS sealed an agreement which will provide free saliva diagnostic testing in high-need under-served communities around the state. The testing began yesterday in the West Valley. The tests are by appointment only, which can be scheduled by visiting azhealth.gov/testing. 

ADHS will be paying ASU up to $12M to fund the initiative. They’ll be using the new test procedure developed by ASU’s Biodesign Institute a few months ago. It’s the first saliva-based test in the state.  They’ve been using it over the past several weeks to test critical workforce including healthcare workers, first responders, and infrastructure personnel. ASU is also using the saliva-based test with employees and students.

ASU’s turn around time is less than 2 days- so that’s an added bonus for these communities!