This past week has brought new information about the Omicron variant of Covid first identified in southern Africa. Omicron has now been found in many additional countries around the world, including the United States. Modeling by infectious disease scientist Trevor Bedford suggests Omicron has a substantial transmission advantage over Delta, the Covid variant that is responsible for over 99% of Covid cases in the U.S. This increases the probability Omicron will ultimately overtake Delta as the dominant variant in the U.S. A more contagious variant here would result in many more Americans becoming infected, potentially straining our health care system’s clinics and hospitals.
There is evidence that immune protection through previous Covid infections and vaccinations is eroded with Omicron. But the extent of such erosion is unclear. Experts expect that some degree of immune protection from infections and vaccines will remain and that getting a booster shot will offer further protection. This is, in part, because Omicron will still be vulnerable to the body’s second line of defense called T-cells that are primed by vaccines and prior Covid infections. They work with our immune system’s antibodies to ward off infection and the development of disease. If a virus escapes the attacks of antibodies, T-cells then get to work killing infected cells.
It is too early to draw confident conclusions, but early data from South Africa hint that Omicron may cause less severe disease. A report from several hospitals in Gauteng Province, where Omicron was first spotted states that most hospitalized patients who tested positive for Covid did not need supplemental oxygen. Few developed Covid pneumonia or required high-level care, and fewer still were admitted to intensive care. But it’s important to note this report included too small a sample of patients to infer much about Omicron’s severity. In addition, many of the hospitalized patients were of a younger age in which Covid infections are often less severe. Even if Omicron turns out to cause less severe disease, if many more people are infected due to its contagiousness, this could still overwhelm clinics and hospitals.
Most current treatments for Covid will likely retain their efficacy against Omicron since they aren’t impacted by its mutations. For hospitalized patients, these treatments include medicines like Dexamethasone and Actemra that decrease inflammation caused by Covid as well as the antiviral medicine Remdesivir.
The most effective treatment for preventing hospitalizations and death from Covid are monoclonal antibodies. Once infused in a patient, they bind to and neutralize the virus. I’ve used them successfully on many of my patients infected with Covid. Early lab studies show that GlaxoSmithKline’s monoclonal antibody called Sotrovimab could be effective against Omicron. On the other hand, there is data suggesting that the monoclonal antibodies created by Regeneron and Eli Lily may be less effective against Omicron.
Fluvoxamine and inhaled corticosteroids such as budesonide are other medicines that have good evidence for shortening duration of symptoms from Covid and reducing the risk of hospitalization. They should continue to help when used in patients with the Omicron variant. Once the antiviral pills created by Pfizer and Merck are available for use, they should retain the benefit they provided when studied against other Covid variants such as Delta.
Our current antigen and PCR tests for Covid will effectively detect Omicron. Thus, home Covid tests will continue to be a helpful tool.
So what should we do in response to the latest information about Omicron? Get vaccinated if you haven’t. If it’s been 6 months since your second Moderna or Pfizer shots or 2 months since your J&J shot, get a booster shot with either Moderna or Pfizer. Continue to wear a mask indoors with people outside your household. Gathering outside is very low risk for infection. If gathering indoors without masks with highly vulnerable people, consider checking home tests beforehand to ensure nobody is bringing an asymptomatic Covid infection. Mentally prepare yourself for some disruption in the next few months if a more contagious variant of Covid becomes common in the U.S. Remember that health involves much more than avoiding a viral infection. Continue to do the things that promote well-being like regular exercise, a nutritious diet, avoiding excessive alcohol use, getting enough sleep, and taking time to relax. Most importantly, engage in activities that bring you joy and fulfillment such as connecting with friends and family.