Researchers at UC Berkeley, the Gladstone Institutes and the Innovative Genomics Institute discovered that the antibodies generated against SARS-CoV-2 and its variants are less effective against the omicron variant.

The omicron variant was first detected in South Africa in late 2021, according to Abdullah Syed, the first author and a postdoctoral fellow at campus professor Jennifer Doudna’s lab. Although COVID-19 has generated many variants since 2020, Syed said the omicron variant is “different” because it had the most mutations and spread more rapidly than other variants.

“What the study really found is that the immune response that we have, especially with two shots of the vaccine or a prior infection, is less efficient against omicron than it is against other variants,” said the study’s senior author Melanie Ott.

Enhanced assembly and immune escape could explain why omicron has a high mutation and transmission rate, according to Syed.

He said omicron is similar to the delta variant in its efficient assembly, but stands out in its ability to evade antibodies at a higher rate than any other variant.

“A large number of people no longer had any effective antibodies against omicron when it came out,” Syed said.

Using blood samples provided by healthcare startup company Curative, Syed said researchers incubated the serum containing antibodies with virus-like particles to test people’s ability to withstand omicron and other variants.

He explained virus-like particles contain all the proteins of the omicron variant, but lack its genetic material, making it safer to work with because it cannot generate an infection.

“This method can be used to analyze the immune response against the variants because you can make these virus-like particles that correspond to the different subvariants,” Ott said.

While Ott noted that people who received the booster shot were able to withstand omicron better than people who were not, the immunity was only temporary.

Syed said the body’s antibodies decline over time, but the booster increases antibody levels temporarily.

“The bigger problem is that the new variants continue to change and evade the immune response,” Syed said.

According to Ott, the study shows that the virus-like particle system can be used to measure people’s neutralizing titers and tailor vaccination accordingly.

The next step for researchers, Syed said, is to study new variants as they evolve and understand why some variants have more enhanced assembly and immune escape than others.

“This is one of the first studies to show that we have a problem with omicron,” Ott said. “If you want to avoid it these days, mask when you are indoors, avoid indoor eating, keep a distance and maybe do not go to these 10,000 people concerts.”