What You Need to Know About Omicron BA.5 Subvariant

Since the less-deadly Omicron variant was identified in Africa in November 2021, and the winter surge in cases subsided, the majority of Americans feel they are returning to some form of normality. In fact, more than a third of people think the pandemic is over¹. But now, rising case numbers and the emergence of the BA.5 Omicron subvariant of the COVID-19 virus are serving as a stark reminder that the pandemic hasn’t ended.

Where did the BA.5 subvariant come from?

The Omicron BA.5 COVID-19 subvariant was first identified on February 6, once again in South Africa, alongside another subvariant labelled BA.4². Since its recognition, the new subvariant has spread to Europe, Asia, and the U.S., and is responsible for more than 50% of positive COVID-19 cases in America as of early July³, the CDC reports.

How is BA.5 different to the original Omicron variant?

The spike proteins of both the BA.4 and BA.5 subvariants have mutated from the original Omicron variant. As the spike proteins are the part of the virus that attaches to human cell receptors, the mutations cause them to be more contagious, which is reflected in the numbers.

In the UK, with the BA.4 and BA.5 subvariants dominant, figures suggested 4% of the country’s population was infected at the end of June⁴. At present, a similar surge, propelled by the BA.5 subvariant, is taking place in the U.S., as gatherings and events over the July 4^th holiday weekend created opportunities for community transmission.

On a more positive note, despite increasing cases, much like the original Omicron variant, BA.5 doesn’t appear to cause severe disease as commonly as previous iterations, like the Delta variant. Although hospitalization numbers have been trending upward since mid-April, they have not come close to the levels reached during previous waves⁵.

What are the symptoms of the BA.5 subvariant?

Experts analyzing the BA.4 and BA.5 subvariants have reported that their symptoms do not appear to be markedly different from the earlier version of Omicron³, with symptoms of the BA.5 subvariant including:

Cough
Runny Nose
Sore Throat
Fatigue
Headaches
Muscle Pains

The experts also advise that BA.5 is less likely to cause those infected to lose their sense of taste or smell, or to experience shortness of breath, than those who experienced the Delta variants of the coronavirus.

How will BA.5 impact vaccines?

Given the sudden surge in cases in countries where BA.5 has been identified, it appears that both BA.4 and BA.5 more easily evade protection from vaccines and the antibodies and immunity generated by previous infection than most previous coronavirus variants⁶.

In response to these subvariants, the U.S. Food and Drug Administration (FDA) expressed its support for a change in the composition of the current COVID-19 vaccine boosters in time for another round of boosters in the 2022 fall and winter seasons. The FDA said⁷:

“In consideration of the committee’s vote and the discussion that took place about the specific SARS-CoV-2 variant to include, and considering the totality of the available evidence, FDA has advised vaccine manufacturers seeking to update their COVID-19 vaccines that they should develop modified vaccines that add an Omicron BA.4/5 component to their current vaccine compositions to create two component (bivalent) booster vaccines.”

In their statement, the FDA clarifies that they only recommend modifications be made to booster vaccines to combat new variants and subvariants, and that they do not suggest making changes to the primary vaccine doses.

Are further mutations and more variants likely?

Yes, it is almost certain that we’ll encounter more variants and mutations of the COVID-19 virus. For as long as the virus spreads through the population, it will continue to mutate, and both new variants and subvariants will arise⁸.

Stuart Ray, M.D., vice chair of medicine for data integrity and analytics at the Johns Hopkins University School of Medicine, has said: “New variants of the SARS-CoV-2 virus are detected every week.” However, he is optimistic that we remain equipped, through vaccines, to cope with future variants. “The virus seems to have some limitations in its evolution ― the advantageous mutations are drawn from a relatively limited menu ― so there is some hope that we might not see variants that fully escape our vaccines.”