New Sub-Variants of Omicron Detected: What to Know About BA.4 and BA.5

When new variants are detected, experts look closely at what mutations have occurred and whether or not these mutations make the virus less likely to be detected by the immune system and, therefore, more likely to cause severe disease.

SARS-CoV-2, the virus that causes COVID-19, uses a spike protein to enter cells and start to replicate in the host. According to the National Institute of Health, if mutations occur on this protein, the virus can more easily enter cells. Additionally, these mutations may allow the virus to evade detection from the immune system, even if a person is vaccinated or previously had COVID-19.

Dr. Robert G. Lahita, director of the Institute for Autoimmune and Rheumatic Disease at Saint Joseph Health and author of “Immunity Strong,” told Healthline that “immune escape” or “immune evasion” happens when the human immune system can no longer detect the virus effectively.

“Now, with Omicron BA.2, there is immune escape, so that’s why people who are vaccinated get infected,” said Lahita.

According to Lahita, if other mutations allow the variant to evade our immune response more easily, that can also cause lower respiratory disease, “or worse,” outcomes.

The research on BA.4 and BA.5 is extremely limited. Currently, several dozen cases involving these variants have been detected by the WHO. According to early findings from the UK Health Security Agency, the BA.4 and BA5 sub-variants have significant mutations on the spike protein that make it different from BA. 2 or other forms of SARS-CoV-2.

Mutations do not mean that the virus is more dangerous or spreads more easily. More research will be needed to understand what these mutations mean.

Lahita said that if there are enough mutations that these sub-variants start to cause serious disease in many vaccinated people, a new vaccine targeting that variant may be needed.

“A new booster that is more specific towards variants with multiple mutations on the spike protein,” he explained.

While current COVID-19 vaccines were developed when other coronavirus variants were more widespread, they are still largely effective even without being changed to target the new SARS-CoV-2 variants that keep popping up.

Blaivas pointed out that these COVID-19 vaccines seem to be doing a great job of keeping most people from getting severely ill or dying from COVID-19.

“That last part is critical,” he said. “Because it saves lives and decreases the crippling aftereffects of COVID, which we saw frequently in the first wave.”

A recent study published by the Centers for Disease Control and Prevention found that people who had at least three doses of an mRNA vaccine were 90 percent less likely to need hospitalization death during the Omicron wave compared to unvaccinated people.

The vaccines have been less effective at stopping symptomatic cases.

Blaivas emphasized that even people at higher risk of severe disease have been largely protected if vaccinated and bolstered.

“If you are at risk, such as being older or having certain health problems,” he advised. “Vaccination is very important to protect you from getting very sick or dying due to a COVID infection.”

Michael Blaivas, MD, Chief Medical Officer at Anavasi Diagnostics, which makes test kits to detect COVID-19, said it would be unusual if the virus didn’t mutate.

“COVID has been mutating ever since humans discovered it and before that as well,” confirmed Blaivas. “It is important to keep in mind that there are many more mutations occurring than we are aware of, all the time.”

He explained that most variations would have no real impact on how the virus behaves, many will weaken the virus, but some make it worse for people.

“This kind of regular mutation is commonplace for viruses, and rates of mutation can be increased by certain conditions like out of control spread of the disease and interactions with other viruses in” people with COVID-19, said Blaivas.

Blaivas pointed out that this announcement is a routine part of the WHO’s responsibilities.

“They have been doing this for other COVID variants before and will continue to do it,” he said. “We are now more aware of the process than before and it is much easier to do than previously.”

Advancing technology means there’ll likely be similar announcements going forward.

“As world healthcare systems got on top of testing and new capabilities were developed, it was much easier to identify and track variants around the world,” said Blaivas.

“These capabilities are still growing, and we will likely see even more variants identified and tracked in the future as the entire system becomes more sophisticated,” he added.

Experts are currently researching potential COVID-19 vaccines that could detect all variants. But it is too soon to know if they are effective.

Lahita emphasized that a universal vaccine could help us avoid another dangerous variant, like Delta.

“You want to make sure that we don’t pop up with a variant that’s immune evasive and highly infective, and clinically dangerous,” he said. “That is killing people like the COVID variant (Delta) did.”

Asked if extreme transmission prevention measures similar to what is being used in China could come to the U.S., Lahita said he doesn’t believe so.

“I don’t think the people would tolerate it,” he said.

Lahita warned that the pandemic is not over since new variants are always possible, and these variants, if they become “immune evasive,” could change our mitigation measures.

“Meaning that we could go back to wearing masks and avoiding people and all that,” he said. “This is not over yet, and I think people need to know that.”

The World Health Organization (WHO) identified two new variants of the Omicron strain, called BA.4 and BA.5, which might have mutations that could allow the virus to evade the immune system even in people with natural and vaccine-generated immunity.

Experts say that this isn’t yet concerning.

They also say that the pandemic isn’t over, and we might still see a variant similar to Delta that can cause severe illness, returning us to masking and social distancing.