North Coast cases continue to rise
Active cases of COVID in Ft Bragg and the immediate surrounding communities have risen to about 100 from 52 active cases just ten days ago. This is a significant increase from what we have seen so far in the pandemic where 20-30 local active cases at any one time was the previous norm. Obviously, the number of actively infected persons is much higher than the number identified as not everyone seeks testing. This is most likely being driven by the Omicron variant which is at least 10 times more contagious than Delta.
In southern California, Omicron comprises at least 70% of new cases with 30% being Delta. In the Bay Area, it appears to be about 60%. In Mendocino County, we don’t know what proportion of new cases are from Omicron. However, given how the cases are so quickly rising I would estimate at least half.
Despite early worries that Omicron might become undetectable in our testing, so far that has not been the case. All three of the standard PCR tests used clinically at our hospitals, Biofire, Cepheid, and Abbott, are successfully detecting the virus as is the Binaxnow home antigen test.
While cases are steeply rising, hospitalizations not as much, even adjusting for the expected time lag between testing positive and ending up in a hospital. This could be due to Omicron being less virulent. It could also be due to the combined protective effects of vaccinations and natural immunity following previous infection. As of this writing, we have no COVID patients in our hospital on the Coast (AHMC) and only three in Willits at Howard Memorial (AHHM) plus another five hospitalized at Ukiah Valley (AHUV).
New Changes in Treatments. When we compare treatments, we are principally concerned about three outcomes: preventing hospitalization, shortening the course of a hospital/icu stay and reducing mortality. So, when we talk about effectiveness, we are speaking in terms of preventing hospitalization, serious illness, and death.
The mainstay for treating patients in the hospital remains dexamethasone, an anti-inflammatory steroid, which we have been using since the beginning of the pandemic. We often supplement this with one of three additional drugs: remdesivir, baricitinib, and tocilizumab. The latter two showing much greater efficacy over remdesivir which is more expensive and falling out of favor.
The monoclonal antibody injection, Regencov (casirivimab plus imdevimab), which we have been using for a while, is falling by the wayside as it is much less effective against Omicron perhaps as low as 30%. A newer monoclonal antibody preparation, sotrovimab, is 65% to 85% effective, however, like other monoclonal antibodies has downside of having to be an IV infusion or an injection under the skin. Sotrovimab is in extremely short supply. Our county received only 20 doses with three being given to our hospital on the Coast. A few weeks ago, the FDA gave emergency use authorization to two medications that can be given as a pill and are as effective or more so than the monoclonal antibodies. The first is Lagevrio (molnupiravir), which has already available. It is also in limited supply, but not anywhere as short as the monoclonals. One pharmacy in Ukiah (Rite Aid on South State Street, Ukiah) and one in Ft. Bragg (CVS on Main Street, Ft. Bragg) were chosen as the first sites to get the drug. This choice was made at the request of Dr. Andy Coren, Mendocino Health Officer, and required approval by the California Department of Public Health (CDPH). The ability to provide drive-through pickup was key so that COVID patients would not be required to enter the pharmacy to pick up the prescription. Dr. Coren is working with the State to get a third pharmacy approved in Willits, but that has not yet happened. Lagevrio is equally effective as sotrovimab. Given its easier administration as a pill and greater availability, it will likely soon replace the monoclonal antibody treatments. The main downside to Lagevrio is a concern that it may not be safe in pregnancy.
The second drug, Paxlovid (ritonivir plus nirmatrelvir), is expected to come out in another 4-6 weeks. It has a couple of advantages over Lagevrio and will likely replace it over time. First, it works in a totally different way and does not carry the same concern about safety in pregnancy. The second is that it is more effective at about 89% and perhaps as high as 96%. The downside is that it is more expensive and slower to manufacture.
Treatments that Do Not Work. The two largest studies looking at ivermectin have conclusively shown no significant clinical benefit. Similarly, hydroxychloroquine has not been considered an acceptable treatment for quite some time as rigorous studies have shown either no benefit or perhaps even harm when used to treat COVID. Vitamin D gets a lot of discussion in social networks, but much of the “science” is more opinion based on anecdotal evidence. The large, randomized trials that have looked at vitamin D supplementation in treating COVID have failed to show clear clinical benefit.
Masks Remain Effective Against Omicron. Omicron’s ability to be more contagious is not from developing some new way to float through the air. Omicron is still spread the same way as previous variants, namely respiratory droplets. The reason it is more contagious is that it is more efficient at entering the host cells. As a result, the minimum number of virus particles required to cause infection is substantially lower. Also, Omicron seems to have some additional abilities at evading our immune system that may also play a role here. So, physical barriers that protect one from respiratory droplets remain effective. These include keeping one’s distance from others, avoiding crowds especially indoors, and wearing a mask over your nose and mouth. However, not all masks are made equal. The most effective remains the N-95 and KN95. Both of these combine thickness, a tight weave, and electrostatic properties to be highly effective at trapping viruses of all types. Their downside is that they must fit snuggly to the face and thus many people find them uncomfortable to wear for long periods. All medical masks are designed for one-time use. If you are careful, you can probably get three or four days of safe use, but since supplies are not as limited as before, I suggest a fresh mask each day.
The second best mask is the medical-grade paper mask also known as the surgical mask. The main way it works is through the electrostatic charge with filtering to a lesser extent. While it is much more comfortable, it does not fit as snuggly to the face which is a drawback. The earloop style and the ties around the head style are equivalent and up to wearer preference. One should discard this mask after just one day use as the electrostatic charge starts to dimmish after that.
At this point, cloth masks are not really considered effective barriers to Omicron since they can let enough virus particles through to potentially cause infection. This was not the case with Alfa and other earlier variants, but times have changed. In order to provide any protection, they need to be two or three layers thick, and the type of material matters. My recommendation is to stop using cloth masks and switch to a medical-grade paper mask. If you are going to be indoors around a lot of other people, consider upgrading to an N-95. Bandanas that hang down over the face and are not secured at the bottom or any other type of similar design are not effective in providing any meaningful safety at this point and should be avoided. Going without a mask altogether does nothing beyond making a social statement.
So, to recap. Cases are rising in the area, probably fueled by the new Omicron variant. While still capable of causing serious illness and death, Omicron may be somewhat less virulent. That, along with previous immunity from either immunization and/or previous infection are helping to keep hospitalization rates lower than expected. However, the sheer number of new infections are still overwhelming hospitals in many parts of the country. Newer treatments in the form of effective pills will soon replace monoclonal antibody infusions. Lastly, you should favor medical-grade paper masks over cloth masks and use an N-95 or KN95 when indoors amongst crowds. You can access this and all previous Miller Reports by visiting www.wmillermd.com.