Just when you thought it was safe to go back in the world, along comes… boom, boom, boom... Omicron! This cycle of fear-vaccine-relief-variant-fear feels like a rollercoaster. Yet, in my opinion, the news is still mostly good.
We may have had to replace the hope for a world without COVID with a new vision of co-existence but we are quickly learning to live, work, and socialize in a world with the SARS-CoV-2 virus.
There has been a huge reduction in the incidence of severe COVID and death where vaccine supply and uptake are high. While Delta has been devastating and Omicron is on the horizon, most Americans–and over 4 billion people worldwide–have been vaccinated. An amazing accomplishment. Recall that in mid-December 2020, there were about 223,000 new cases and over 3,000 deaths in the United States each day. In contrast, in December 2021, that number had decreased to 120,000 new cases and 1,000 deaths per day.*
By all accounts, vaccines have helped reduce the devastation of this pandemic and allowed us to return to life. It’s not the same as it was before, but lots of “normal” is returning. Many of the things we missed just a year ago (theatre, restaurants) as well as many we did not (traffic, overbooked flights) are returning.
Greek alphabet soup
Let’s turn to awarding Greek alphabet letters, ominous lurking threats, and the next it’s-Greek-to-me viral variant.
As a quick review: Viruses frequently make errors when they replicate; like a typo in a document. This mutation alters the virus’s genetic code; the resulting mutated virus is called a variant. A few typos in a document rarely change the meaning of the paragraph; similarly, most viral mutations are negligible and have little impact on how the virus behaves.
boom, boom, boom…
However, when one or more mutations demonstrate genetic changes that are associated with concerning changes, we call this a “variant of interest” and keep close tabs on it. If evidence emerges that a variant of interest is capable of disadvantageous (to humans!) behavior, it is deemed a “variant of concern” and awarded a Greek alphabet letter, Alpha, Delta, Omicron, etc.
In order to alert the world to a potential threat, the designation “variant of concern” is typically applied before scientists fully characterize the risk a variant presents. So, while it is reasonable to be more vigilant when variants emerge, I urge you to VET before you bet – at least let scientists vet! -- when it comes to variants of concern.
By vet I mean literally “carefully examine” and acronymically consider “V-E-T”.
Specifically, when watching a variant of concern, epidemiologists and other scientists focus on three characteristics. The interplay of these VETted characteristics matters. For instance, a variant that spreads like wildfire but is substantially less severe than other circulating variants may not be a great concern if it does not lead to the need for many people to get medical care all at once. Similarly, an extremely virulent variant that escapes our protections may not be a reason for alarm if it cannot outcompete other circulating variants and spread successfully.
Have you ever wondered how an epidemiologist spends their time? Well, I VET data, meaning I review it, then I interpret the source, strength, consistency, and biological plausibility of the existing evidence to draw conclusions. It’s such a fun way to review information.
Virulence: Virulence is a question of whether disease caused by the variant results in a greater proportion of hospitalizations and deaths among those infected.
Escape Potential: Some variants, per the cartoon above, are escaping our defenses. Specifically, they are better able to evade our protective measures by, for example, being less-easily detected by a COVID-19 test, causing disease that does not respond as well to current treatments, and/or evading the immune protections we have built through natural infection or vaccination.
Transmissibility: This is the variant’s ability to spread, specifically how many people does one person infect, on average? A high number means fast spread and the potential to overwhelm our health system.
Vetting Variants: Viruses in the Lab and Viruses in the World
Getting a variant vetted is not an overnight process. Early evidence is anecdotal or based on laboratory studies. But the most actionable proof is in the pudding and the pudding here is evidence from large epidemiologic studies of people in the world, not just cells in a lab. Both may tell us the same thing, but lab data without real-world evidence leaves substantial gaps in our understanding of the impact of a viral variant out in the world.
boom, boom, boom...
Some of the alarm bells we’ve heard about Omicron involve the quantity of changes to the spike protein, the part of the virus that binds to our cells and around which both vaccines and some therapies are created. Omicron has 32 of these changes; Delta had nine. Although it may seem worrisome, the number of changes does not tell us a great deal about the viral behavior these changes induce.
For example, some of the genetic changes in Omicron are present in other variants. This offers evidence that Omicron has the potential to transmit more readily. Laboratory studies of the Omicron variant indicate that it may also be an escape artist–able to slip through our vaccines and infect previously infected or fully vaccinated individuals.
boom, boom, boom...
While lab data offer just part of the picture, real world data offer a growing body of evidence that Omicron is a highly transmissible variant. However, an increased ability to infect a vaccinated person is not the same as an increased ability to cause severe illness in a vaccinated person. In fact, to date no variant has been able to evade the protection that FDA-approved COVID-19 vaccines provide against severe infection, hospitalizations, and death.
Adaptive Immunity may work less well in the face of “escape artist” variants, but it is still very likely to offer protection (aka Your Amazing Immune System)
The talk of “waning” antibodies might leave you with waning hope, but take heart! Our immune systems offer wide-ranging protection. We have heard a lot about neutralizing antibodies -- how vaccines can create them, and how boosters can restore their levels as they wane over time. As a result of COVID-19 infection or vaccination, neutralizing antibodies circulate and are on the lookout for the virus. Their job, should they encounter the virus, is to block it from attaching to and entering the cell. Many lab-based studies of variants measure how vulnerable variants are to vaccine or infection-created neutralizing antibodies. This is helpful but incomplete information.
When neutralizing antibody levels drop, T cells (think T for “Target”) can still come to life in the presence of the virus or its variants. These immune system patrols narrowly focus on an enemy they have been trained to recognize, the SARS-CoV-2 virus. They can even recognize an enemy that has changed somewhat (mutated). It is helpful to visualize an old-fashioned “Wanted” poster with the “bad guy” pictured. Say you see the “bad guy” but he is wearing glasses; he appears a bit different but is still recognizable. When the SARS-CoV-2 viral “bad guys” mutate, our immune system is not necessarily fooled. In fact, experiments done with blood samples in lab settings offer early evidence that Omicron is recognized by the T cells produced after vaccination; it’s good news but we need epidemiologic studies to round out our understanding.
boom, boom, boom… How does Omicron stack up to VETting?
Virulence: There is limited evidence on Omicron’s virulence, even some talk of milder disease but the jury is still out on this one. Evidence for severity lags behind evidence of transmissibility so this is a wait and see.
Escape: Omicron seems to be an escape artist and might cause a great deal of mild to moderate illness even in the vaccinated but most scientists expect vaccines and boosters will continue to blunt the risk of severe disease. Omicron looks different than prior variants, but it should not be entirely novel to the vaccinated or previously infected.
Transmission: It does seem to be more transmissible as supported by lab data and growing epidemiologic evidence. A highly transmissible variant, even one with less virulence, is a risk. Even if Omicron has a lower hospitalization rate than Delta, if Omicron infects more people, more quickly, it could still overwhelm health systems that won’t be able to effectively treat COVID-19, or any other medical problem, if beds and staffing cannot keep up.
Ok we’ve VETted Omicron and it looks a bit worrisome, what next?
We need to center ourselves in being alert but not alarmed. Omicron is not the first variant of concern nor will it be the last. As this virus becomes endemic like the flu, we will get adept at right-sizing our reaction and understanding the risk this evolving virus poses; we should act, not overreact.
Everyone has a unique risk tolerance. You have to follow yours; all the things that worked before should work now, though certainly some measures have declined in their ability to protect us. That does not mean they are not worth doing.
Stay outside: Yes, I know it is December but you might be in Honolulu or Tucson or Miami. If you can be outside comfortably, that’s always a better bet.
Avoid or vet crowds: Avoid spending time in crowds or vet the crowd. An example of a vetted crowd is one for whom you have determined vaccination proof is required.
Robust masks. There are so many cool masks; my favorite is one that displays the entire periodic table of elements; it always gets a reaction :-)! When case numbers are high in my area, I wear it over a surgical mask; this adds a layer and helps close the gaps around the loose-fitting surgical mask. For highest level of protection N-95, KN95, and KF94 are all robust masks with the latter two available in pediatric sizes.
Ventilate and filter air through HEPA-based portable air filters or open windows. Ask your guests to bring an extra layer in case it gets too drafty for them.
Beware of hygiene theater. You can go back to this post, but the basic idea is that COVID-19 is airborne and while washing your hands is a great idea for so many reasons, neither excessive disinfection nor wearing gloves is likely to offer you much protection from COVID-19.
Use rapid tests… correctly. If you are going to self-test, watch a video of the brand of test you are using to prepare. Test in an environment of 55F (13C) or greater and store above freezing to reduce the risk of false negatives. Most importantly, remember that no test is 100% accurate and rapid antigen tests that you can buy at the local store are best used the day of need. In other words, if you tested today, you tested today. Tomorrow is a new day and needs a new test. These tests are most predictive of a person’s point-in-time probability of transmitting (and to a lesser degree being infected with) COVID-19.
It’s a brand new variant but much is known and knowable
Omicron is on the horizon. It looks like it has the potential to spread rapidly. It may cause illness, even in the fully vaccinated. If prior infection or vaccination protects against severe disease with Omicron, as it has with other variants, we will have a good chance of avoiding hospital surges in the areas of the country and the world with high levels of vaccination and/or prior infection. But there is no need to guess, so much as a need to vet Omicron’s characteristics in the real world. You can bet scientists and epidemiologists are already hard at work doing just that!
As we close out 2021, I am grateful that I can be here to help share reliable information and that you’ve taken the time to read my blogs. Thank you and best wishes for 2022.
*This comparison is not apples to apples - much testing is now taking place at home, for instance therefore lowering the case count but less likely to have an impact on the death count.