As the omicron variant spreads rapidly across the globe, Memorial Hermann Health System is staying up-to-date on the latest information about its transmissibility and pathogenicity, which will ultimately inform how contagious and dangerous this strain may be. While there are still many unknowns surrounding this newly evolved strain of COVID-19, scientists have determined that it has more than 50 mutations in its viral genome and that it is spreading rapidly among populations. Below, Dr. Annamaria Macaluso Davidson, Vice President of Employee Health Medical Operations at Memorial Hermann Health System, breaks down everything we know to date—and all the information scientists are scrambling to find out.

The Omicron Variant is Contagious

The omicron variant is spreading rapidly—more quickly than the delta variant—but scientists are still trying to determine why. One explanation is that the makeup of this variant, including its mutations, allows it to be more transmissible. The second hypothesis stems from a phenomenon known as immune evasion, in which a virus mutates in such a way that helps it escape detection by antibodies. Previous COVID-19 infections, as well as the COVID-19 vaccine, create antibodies to fight the virus, but if this omicron variant evolved to evade those antibodies, that means neither previous infection nor the vaccine may be highly effective against this strain.

We Still Do Not Know if this Variant Causes Severe Disease or Milder Symptoms in the General Population

So far, the omicron variant does not seem to be as severe as the delta variant, meaning those who have contracted it are not yet falling as severely ill, although these are just initial observations. It is still too early to tell if these early signs offer hope that the omicron variant is less deadly than its predecessors, including delta. Clinicians and researchers will know more in the coming weeks as they collect and analyze more data.

Booster Shots are Highly Recommended as Protection against Omicron

It is still unknown exactly how protective each COVID-19 vaccine is against the omicron variant. A new study just released by Pfizer revealed that while its first two vaccine doses still provide protection against severe illness and hospitalization, getting a booster dose increased antibody protection by 25 times and reduced the likelihood of getting mildly ill or an infection at all. Currently, the Centers for Disease Control and Prevention (CDC) recommends booster shots for all adults who received their second doses of either the Moderna or the Pfizer/BioNTech vaccine more than six months ago, and they recommend a booster for anyone who received a Johnson & Johnson vaccine over two months ago. Notably, eligible adults do not need to get the same “brand” of vaccine for their booster as their previous dose(s). For example, someone who completed the Pfizer vaccine series six months ago can choose to get a booster shot of either the Pfizer, Moderna or Johnson & Johnson vaccine.  It is also worth noting that the U.S. Food & Drug Administration (FDA) has granted emergency use authorization to the Pfizer booster for teens ages 16 and 17.

Current Testing Should Accurately Detect the Omicron Variant

Despite the more than 50 mutations to the virus, including one that specifically affects the spike protein, early data suggests that the current COVID-19 tests on the market do accurately detect the omicron variant. This is welcomed news, as accurate and efficient testing is critical for controlling the spread of any contagious disease.

There are still many questions waiting to be answered, including whether or not the omicron variant will lead to severe disease and death in vulnerable populations (the unvaccinated, elderly or immunocompromised), whether we will need to create new vaccines to effectively fight this variant or others in the future, and how and why this variant appears to be so contagious. What we do know is that booster shots will offer additional protection to those who are already vaccinated, and that individuals who are unvaccinated should strongly consider getting the COVID-19 vaccine as soon as possible. We also still recommend practicing safety measures to protect yourself and your loved ones against all strains of COVID-19, including delta, which is still circulating nationally and here in Houston: wear a mask in crowded indoor spaces, wash your hands, and watch your distance as appropriate.