23 May 2021 Blog Post: Approaching Containment, Hoping for Elimination

23 May 2021 Blog Post: Approaching Containment, Hoping for Elimination

What a year it has been. Here in Los Angeles County we experienced a pandemic high of COVID-19 cases the week of 1/5/2021 at 145.0 new daily cases per 100,000 population. For the most recent week of data ending 5/18 we have dropped to 1.8 new daily cases per 100,000.  Viral containment is generally defined as fewer than 1 new daily case per 100,000 and we should be there within the next 2 weeks.

Similarly mortality has plummeted from 2.76 deaths per 100,000 the week ending 1/12 to 0.04 deaths per 100,000 last week (Figure 1 below).

A number of factors account for this dramatic turn around, but none more powerful than the role of vaccination. It is for this reason that mortality rates declined more precipitously than did case rates.  However, mortality rates have been flat – low at 0.04 per 100,000 – but still flat for the past three weeks.

With vaccination as our best and most effective preventive measure, then it is here that our public health officials need to focus their efforts.  There remains a significant disparity in vaccination rates, with Latinx and African-American residents under the age of 65 less likely to be vaccinated.  Over 75% of White and Asian residents over the age of 65 have been vaccinated, compared to 63% and 66% of African-American and Latinx residents. This difference is even more marked among those under the age of 65. Whereas 70% and 62% of Asian and Caucasians have been vaccinated, these drop to 39% and 44% for African-American and Latinx individuals (source:  http://publichealth.lacounty.gov/media/coronavirus/vaccine/vaccine-dashboard.htm#selectcity).

This remains our health officials’ greatest responsibility at this point, as we have made tremendous strides towards viral containment. But to move from containment to elimination, we must address these glaring disparities.

𝗦𝗶𝗴𝗻 𝗨𝗽 𝗳𝗼𝗿 𝗢𝘂𝗿 𝗡𝗲𝘄𝘀𝗹𝗲𝘁𝘁𝗲𝗿

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18 May 2021 Blog Post: CDC, Masks and “The Science”

18 May 2021 Blog Post: CDC, Masks and “The Science”

I – like most of you – was completely caught off guard by the @CDCGov guidance this week stating that if you have been fully vaccinated then you can “resume activities without wearing a mask or staying 6 feet apart.” As somebody who has been wearing a N95 for my entire workday since March of 2020, nobody had more reason to be thrilled on an individual level than I.  Except, I wasn’t.

The announcement seemed to catch most municipalities off stride as well, as evidenced both by an initial muted response as well as some very long press interviews by the CDC Director on weekend news programs. California State Health Department and the Los Angeles County Health Department, as you probably know, announced that mask mandates would extend until June 15th, 2021. The same day that our functionally abandoned tier system is officially abandoned.

What is interesting to me is that both the CDC and our State/County/Local Health Departments are wrong. Further, this indistinct messaging (apparently the CDC did not have discussions with hardly anybody in state or local governments about their announcement) is emblematic of how disrupted our public health system has become. Traditionally, the CDC functions in an advisory role and provides expertise. Public health decision-making and communication is the role of the municipal health department. From the outset of the pandemic, however, the Executive Branch essentially discredited them as experts and, so, this most recent communication seems to be an attempt to restore their former luster.

However, neither the CDC nor California State pronouncements make any sense.  Why?  The core issue in public health communication lies in the Venn diagram of personal versus public health and, in this case, the CDC made the wrong call. They have over-emphasized the personal over the collective risk.  Let me explain further. (Side note:  for future reference, this disconnect can be identified when folks start talking about ‘the science.’)

At the individual level, the CDC has set forth a perfectly valid recommendation. In my own clinical experience I have only seen a handful of COVID-19 infections after vaccination. In all of these instances, the exposure occurred 3-4 days after vaccination, well within the 5 week window of safety recommended by Pfizer and Moderna. Interestingly, the J&J vaccine guidance suggests that one is fully protected from infection two weeks after the jab – although the New York Yankees’ experience might make us rethink that recommendation and extend it to five weeks (a topic for another time).

However, at the population level the CDC has completely overstepped their bounds. Any communication of this magnitude needs to be more carefully signaled, explained and then applied. For instance, the CDC could have shared vaccination percentage targets or incidence rate goals or hospitalization metrics as a way to gauge the loosening of restrictions. Instead, they incited a wholesale mad dash for the door that has left some states simply abandoning all mask guidance whatsoever (even among the unvaccinated) or other states (like North Carolina) which had clearly delineated metrics for mask lifting to simply open up.

And it isn’t as if the United States is on its own here – there is a perfectly good example to follow from Israel which has fully vaccinated 56% of its population.  Israel began its vaccination campaign on December 20th, 2020 prioritizing those 60 years of age and above. Cases and hospitalizations in this group peaked around January 10th and from January 15th until February 24th, cases, hospitalization and deaths fell rapidly. Cases then shifted to younger age groups until they too were prioritized for vaccination.

A careful analysis of Israel’s implementation programme was published recently in Nature by Rossman et al (link: https://www.nature.com/articles/s41591-021-01337-2).  The key finding in that paper was:

“Decrease in the clinical measures that we analyzed occurred only after more than 50% of the population in a given age group had been vaccinated by the first dose or recovered “

Currently in the United States, 47.7% of the total population has received at least one dose of the vaccine so we are very, very close to the threshold established by data from Israel (note that some will throw in natural infection rates to augment this number and they aren’t wrong, but the percentage they use is 30-40%. In our clinic under 8% of our population has antibodies consistent with natural infection). However, we must acknowledge that there are significant disparities in vaccination rates – by age, gender and ethnicity. For instance, vaccination rates are 0% for those under the age of 12 – jokingly I have heard people say that the CDC mask guidance includes “don’t have children under 12.”

In Los Angeles County for instance (data link: http://www.publichealth.lacounty.gov/media/Coronavirus/vaccine/vaccine-dashboard.htm), three groups have first dose vaccination rates above 50% – Native American/Alaskan Native (56.7%), Asian (66.0%) and White (59.1%).  Vaccination rates are significantly lower among African American individuals (36.5% first dose) and Latinx (40.2%).

It is for this reason that California’s guidance also falls short. By establishing an arbitrary date (6/15/2021) for rescinding mask mandates, we again miss an opportunity to link mitigation effort relaxation with measurable outcomes. Instead, we have pushed a community obligation down to the individual level, isolating those who may have legitimate concerns about vaccinations or simply have not had the opportunity to receive one.  

Wouldn’t it be much better if we said we would all continue to wear masks until every demographic stratum of our community met or exceeded a 50% 1st dose vaccination threshold? This would best demonstrate the previous CDC adage of “my mask protects you and your mask protects me.”

𝗦𝗶𝗴𝗻 𝗨𝗽 𝗳𝗼𝗿 𝗢𝘂𝗿 𝗡𝗲𝘄𝘀𝗹𝗲𝘁𝘁𝗲𝗿

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11 May 2021 Blog Post: On Containment and “Go For Zero”

11 May 2021 Blog Post: On Containment and “Go For Zero”

If you missed it yesterday, a Bengal Tiger was on the loose in a Houston neighborhood. I found it interesting that somebody would keep on in their backyard, but also sort of terrifying (link:  https://www.nbcdfw.com/news/local/video-shows-tiger-in-front-yard-of-houston-neighborhood/2628266/)

So what does a loose Bengal tiger in a Houston neighborhood have to do with COVID-19?  I’m glad you asked.  And while it isn’t customary to respond to a question, I’ll ask one.  What, if you were a neighborhood resident, would be the first thing you’d ask after hearing about the tiger?

Most would say – was it caught?  Or, in epidemiologic terms, was it contained? 

An even better question would be “do I have to worry about it again?”

These are the same questions we should be asking as a community, a county and a country. Not “when will we reach herd immunity?” but instead, “when will we reach containment?” and then, “when will we eliminate COVID-19 entirely?”

So how do we know when we reach containment and what does it mean in practical terms?  Lucky for us, the Harvard Global Health Initiative has defined containment as fewer than 1 new daily case per 100,000.  As Figure 1 shows below, we are slowly approaching that goal here in Los Angeles County. We are now at 2.5 new daily cases per 100,000 population

The last two months have brought very slow (but steady) declines in incident case rates but more rapid decrease in mortality rates (Figure 2). The more steep decline in mortality indicates that vaccines (which provide essentially 100% protection against hospitalization and death) are indeed working.

So now that we have defined containment, and find ourselves at a caseload that only needs to drop by 1.5 new daily cases per 100,000 population – what’s next?

To find that answer, we need to turn to a country that has been successful in not just containing the virus but eliminating it – Australia.  How did they do it?  Quite simply, they moved past “flattening the curve”and “slowing the spread” but instead insisted upon “zero community transmission.”  And they accomplished it without one very powerful tool which we have here in the US – they did it without vaccines.

  1. “A strong test-trace-isolate system is crucial in getting case numbers under control and preventing further outbreaks.”  This takes an army of contact tracers – a reasonable estimate is 30 per 100,000 population which would mean 3,000 full time tracers in Los Angeles County. Further, at least 90% of identified contacts would need to be traced and it is here that we fall far short with 47% traced in the last 7 days, and 44% cumulatively (link:  http://publichealth.lacounty.gov/media/coronavirus/data/contact-tracing.htm)
  2. “Be explicit about the goal and what should be done to achieve it.” This is also a point at which our US and County public health messaging has become muddled. The focus on ‘herd immunity’ and masking/unmasking obscures our overall goal which is to eliminate community transmission.
  3. “Be clear about when restrictions will be phased out (and in).”  Again, this is another core issue, in California particularly where our tier system is being phased out. Without a structure, we are left to guess what we may be able to do and when we may be able to do it.

Let’s be very clear here, we have made tremendous strides in Los Angeles County and are approaching containment. A redoubled public health commitment from our County Health Department, most particularly when it comes to contact tracing, will get us to zero. Have you seen the pictures of Australians at concerts?  Walking in crowds without masks?  We are almost there – and with the huge advantage of protective, effective vaccines.

It is not enough to get to zero; one also has to plan to stay zero. 

And, best of all, plan ways to celebrate it.

𝗦𝗶𝗴𝗻 𝗨𝗽 𝗳𝗼𝗿 𝗢𝘂𝗿 𝗡𝗲𝘄𝘀𝗹𝗲𝘁𝘁𝗲𝗿

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2 May 2021 Blog Post: Further Decrease in COVID-19 Mortality Rates In Los Angeles County

2 May 2021 Blog: Further Decrease in COVID-19 Mortality Rates In Los Angeles County

Today Los Angeles County reported no new COVID-19 related deaths.  The last time we had a zero count was March 18th, 2020. Today’s count is an additional manifestation of the continued divergence between case rates and mortality rate (Figure 1 below).

The peak in cases occurred the week of January 5th (at 143.7 new daily cases per 100,000) and deaths occurred a week later at 2.66 daily deaths per 100,000.  However, since that time these rates have plummeted and, for the week ending April 27th, there were 3.1 new daily cases and 0.04 daily deaths, both per 100,000 population.

Although we have covered this topic before, we are continuing to see a greater rate of decline in mortality rates than cases.  Case rates have remained relatively steady for the last month and a half:  4.4, 4.2, 4.4, 4.5, 4.0 and 3.1.  However, in that same time period mortality rates have been: 0.20, 0.17, 0.11, 0.09, 0.05, and 0.04. This is directly attributable to the efficacy of the COVID-19 vaccine which provides essentially 100% protection against hospitalization and death.

But the relatively flat COVID-19 case rate represents the continued laissez-faire attitude of the County Health Department in terms of actually containing COVID-19 [Note: “containment” is formally defined by the Harvard Global Health Institute as fewer the 1 new daily case per 100,000 – in Los Angeles we are typically 4-5 times above this goal]. Without a focus on containment and then eradication, we will ultimately transition from a pandemic to an endemic state. One would rather, of course, eliminate the virus entirely but when a virus becomes endemic (an example is HIV), it will continue to circulate in the population, causing sporadic infections. Contact tracing is the solution to eliminating COVID-19 entirely from our population, but the County continues to have absolutely abysmal case follow-up rates.  Although there were only 1,291 cases in the past week, the Health Department only completed 594 interviews (46%). This is only slightly better than its performance through the entire pandemic – 44.8% of more than 470,000 cases.

In spite of this, there is only good news when it comes to our current COVID-19 state in Los Angeles County.  At the height of the pandemic, there were over 24,000 active cases per 100,000 population.  Now?  27 active cases per 100,000 – a 99.9% decrease.

𝗦𝗶𝗴𝗻 𝗨𝗽 𝗳𝗼𝗿 𝗢𝘂𝗿 𝗡𝗲𝘄𝘀𝗹𝗲𝘁𝘁𝗲𝗿

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