What you need to know about COVID-19 subvariant BA.2

The main difference between BA.2 and other variants is that it is even more transmissible than past variants, allowing it to replace the BA.1 subvariants as the dominant strain in most countries, including in the United States.

COVID-19 cases are on the rise again in our community. To help remind you how to protect yourself and others—as well as provide information on the BA.2 subvariant—we sat down with Dan Diekema, MD, hospital epidemiologist and infectious disease specialist.

What is BA.2?

Viruses like COVID-19 continuously evolve as changes in the genetic code (genetic mutations) occur during replication of the genome. A variant has one or more mutations that differentiate it from other variants of the SARS-CoV-2 viruses. The omicron variant, like other variants, is comprised of a number of lineages and sublineages. A lineage is a genetically related group of virus variants derived from a common ancestor. The three most common lineages of omicron currently are BA.1, BA.1.1 and BA.2. Source: CDC.

What markers do you and your team use as indicators of a changing environment as it relates to COVID-19?

We use several different sources of information to help understand how the pandemic is changing, including:

  • The number of new cases reported nationally, statewide, in Johnson County, and among our patients and employees
  • The percentage of tests performed at UI Hospitals & Clinics that are positive for SARS-CoV-2
  • The number of patients admitted to UI Hospitals & Clinics for treatment of COVID-19
  • The proportion of new or emerging variants of the virus (such as BA.2) that are found among our patients
  • The amount of SARS-CoV-2 virus found in wastewater samples from different parts of the state and the nation

Because none of these individual measures is perfect, we can better predict the current and future risks of COVID-19 by looking at all the information together. When all of this information taken together suggests significant changes in the way COVID is affecting our environment, we adjust our protocols and guidelines to keep our patients, staff and community safe.

What’s different about this new subvariant?

The main difference between BA.2 and other variants is that it is even more transmissible than past variants. This has allowed it to replace the BA.1 subvariants in most countries, including now in the United States. By the beginning of this month, BA.2 was responsible for more than 70% of all COVID-19 cases in the U.S., and more than half of all cases in Iowa.

Fortunately, BA.2 does not cause more severe disease than the other variants subvariants of SARS COV2, including omicron, and their subvariants. The current COVID-19 vaccines also work just as well against BA.2 as they do against the other variants and subvariants.

So, the rise of BA.2 just increases the importance of getting vaccinated and getting a booster dose if you haven’t done so already. It also means we should carefully maintain good prevention practices, including wearing a face mask, social distancing, and hand hygiene. These precautions are to keep you and your family safe.

Why should I get vaccinated if I can still spread the virus to others after vaccination?

Although vaccinated persons can still spread the virus, receiving a vaccine does decrease the risk of infection and subsequent spread. Even more importantly, receiving a COVID-19 vaccine and a booster dose provides high protection for the affected individual against severe disease, hospitalization, and death from COVID-19, including infections due to the BA.2 subvariant.

If I’m eligible for a second booster, when should I get it?

The best timing to receive the second booster dose is still being closely studied and evaluated. Because the first booster dose remains highly protective against severe COVID-19, some eligible individuals may elect to wait until later in the summer or fall to receive their second booster. However, if you are at higher risk for severe COVID-19, it is a good idea to get the second booster now.

If you have relaxed your safety protocols, like mask wearing, in recent weeks, now is the time to get back to it. Wearing a mask, along with getting vaccinated and boosted, are important to avoiding the BA.2 subvariant.

Last reviewed: 
April 2022

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