William Miller, MD
End of 2021- COVID Updates
As our second year of the pandemic draws to a close, a few updates on where things stand are in order.
Omicron, the new variant, is quickly becoming the dominant strain of the virus around the globe. Currently, about 60% of new cases in the US are Omicron with 40% being Delta. This is roughly the same for California where estimates range from 50 to 70% Omicron. Omicron is out competing Delta because it is more contagious, meaning that it is much more efficient at gaining access to our own cells. This is happening because the spike protein that is that key that fits into the host cell lock is better at unlocking the cell and gaining entrance. Once inside, it takes over the host cell machinery converting the cell into a miniature virus producing factory.
Another way that Omicron is more contagious is that various mutations have led to its ability to evade our immune system somewhat better than previous variants. This has potential implications for two of our strategies for fighting the pandemic; vaccines and monoclonal antibodies. Current vaccines are showing slightly less ability to ward off infection than before. The good news is that being “fully vaccinated” with Pfizer, Moderna or Johnson followed by getting a booster from Moderna appears to still be more than 80% effective in reducing the risk of hospitalization, serious illness and death. Israel, which has led the world in adopting an aggressive vaccination strategy, has started recommending a second booster shot for individuals at highest risk to be given 3 months after the first booster. It remains unclear if there is significant benefit to this strategy.
The other implication of Omicron’s evading the immune system is that the monoclonal antibody treatment we have been giving to high risk patients in the first week or so of COVID infection is significantly less effective. This is the REGEN-COV product (a combination of casirivimab and imdevimab) which can be given either as an IV infusion or under the skin subcutaneously. A newer generation of monoclonal antibody, sotrovimab, has been developed that is more effective against Omicron, but Mendocino County is expected to receive only 20 doses of the treatment initially. Hopefully, the pill treatments described later in this article will take the place of monoclonal antibody infusions as they will be much easier to administer and more available.
Unvaccinated persons remain the principle pool for continued spread of the virus worldwide. While roughly 60% of the world’s 7.7 billion people have received at least one COVID vaccine shot, it is not evenly distributed. There are still many countries, especially those in Africa, were less than 2% of the population have been vaccinated. In the US, where 62% are fully vaccinated (with 78% having received at least one shot), the majority of both new cases and hospitalizations remain in the unvaccinated group. This rate is reported as cases per 100,000 population which makes comparisons more accurate and simpler. Currently, in the US, the hospitalization rate for COVID in unvaccinated people is 75 per 100,000, compared with 4 per 100,000 in vaccinated people.
The virulence of Omicron remains unclear. Early data from South Africa, where the variant was first identified, suggests a much lower rate of hospitalization with Omicron versus Delta. Subsequently, there have been several small studies that have reported mixed results, mostly indicating that it is either equal to Delta or somewhat less virulent. The current surge of new cases being seen in New York is mostly driven by Omicron, yet the rate of hospital cases is lower than expected given the number of new infections. Again, this suggests that Omicron may be somewhat less virulent. We need to look at this carefully and keep in mind that a variant that is more easily spread may still fill up hospitals and strain our healthcare system by sheer numbers even if it is less virulent. Nonetheless, it is much better than being the other way, more contagious and more virulent.
Last week, the FDA gave Emergency Use Authorization (EUA) to both Lagevrio by Merck (generic name molnupiravir) and Pfizer’s Paxlovid (generic name is ritonivir/nirmatrelvir combination). These are both pills taken by mouth that reduce the risk of serious illness from COVID if started within the first five days of symptom onset. Lagevrio is going to be available first and reduces risk of hospitalization by 50%. Paxlovid reduces that risk by perhaps as much as 89%, but its availability will lag by 6 to 8 weeks behind Lagevrio as it is more complicated to manufacture.
As with pretty much everything related to this pandemic, the initial availability will be limited until production and distribution is fully up to speed. Thus, local health departments will be asked to control how the drugs are distributed. I recently spoke with Dr. Andy Coren, Mendocino County Health Officer, about how this will work. He stated that initially only one pharmacy in each of the three major communities (Ukiah, Willits and Ft. Bragg) will be designated to stock the medication. Exactly which drug stores it will be is currently pending approval by the California Department of Public Health (CDPH).
“We hope to have doses of molnupiravir available in our county by mid-January,” Coren said. “If we get enough of a supply, then we plan for all three major communities to have at least one pharmacy that can dispense it. However, if there is a very limited amount, then we may have to start with just one site which would probably be in Ukiah. Of course, none of us wants that as it is going to be a hardship for people to travel to get the drug.”
For more details and comparison of these two new drugs, please check out my Miller Report “New COVID Treatments on the Horizon” which came out on November 22nd. You can access this and all previous Miller Reports by visiting www.WMillerMD.com.