By Jennifer O'Hara
The BA.5 omicron variant is now the dominant strain in the U.S., and it is leading to a new wave of COVID-19 infections. BA.5 was responsible for nearly 54% of COVID-19 cases in the U.S., and BA.4, a similar variant, accounted for another 17%, according to the latest data from the Centers for Disease Control and Prevention.
Experts are concerned because this particular variant appears to be good at evading the immune system.
"This BA.5 variant is hypercontagious, and right behind it, new variants are coming," says Dr. Gregory Poland, an infectious diseases expert and head of Mayo Clinic's Vaccine Research Group. "We will continue to generate these variants until people are masked and immunized."
A team of scientists within Mayo Clinic's COVID-19 Sequencing Command Center is at the forefront of tracing the genetic evolution of SARS-CoV-2, the virus that causes COVID-19. The extensive research and surveillance operation involves conducting hundreds of sequences of the COVID-19 virus each week.
"Our overarching goal is to conduct impactful scientific research through genomic sequencing to improve patient care, inform the development of therapeutics, advise hospital epidemiology, and serve our communities and people around the world," says Bobbi Pritt, M.D., who oversees the COVID-19 Sequencing Command Center and directs Mayo Clinic's Division of Clinical Microbiology.
A key resource in the ongoing investigation is Mayo Clinic's COVID-19 biobank, which was quickly mobilized at the pandemic's start. The vast library of COVID-19-positive biospecimens, which were contained with patient consent ― including nasal swabs, serum, plasma, blood, urine and stool samples, as well as corresponding clinical and patient-provided data ― is helping scientists advance the understanding of the virus.
For Dr. Pritt and her team, the biobank is essential for analyzing samples in real-time and going back in time to scour the virus's genetic code from early on in the pandemic.
The COVID-19 biobank serves dozens of other Mayo Clinic scientists who are working to improve patient outcomes by identifying and understanding the unique factors contributing to disease severity.
Each biosample, stored in large, minus 80 degree Fahrenheit freezers, holds potentially valuable information about SARS-CoV-2 and the pathology of COVID-19. For example, blood contains DNA, antibodies, serum and plasma that could provide information about a person's immune response and susceptibility.
Konstantinos Lazaridis, M.D., the Carlson and Nelson Endowed Executive Director for Mayo Clinic's Center for Individualized Medicine, is leading his team in exploring which genes influence disease outcomes.
"Our aim is to answer questions about the potential genetic predisposition of developing the infection and the long-term outcomes of the disease," Dr. Lazaridis says. "We may be in a position to say why some patients with COVID-19 develop blood clots or a severe inflammatory reaction. Or why some patients have neurologic impairment while others show no symptoms at all."
Dr. Poland explains that the transmissibility of BA.5 represents the evolution of the virus to become more contagious and able to evade immune protection from previous infection or vaccination.
"Whether you've been vaccinated, whether you've been previously infected, whether you've been previously infected and vaccinated, you have very little protection against BA.5 in terms of getting infected or having mild to moderate infection," says Dr. Poland. "Thankfully, you still do have good protection against dying, being hospitalized or ending up on a ventilator if you are up to date on your vaccinations."
Due to the consequences of reinfection, including the possibility of long COVID-19, Dr. Poland urges people to continue to take precautions to protect themselves.
"The reality is, it's important to be up to date on the COVID-19 vaccinations that are recommended for your age group, health condition, etc.," says Dr. Poland. "Sometime this fall, we may well have a variant-focused vaccine, so get it when it becomes available. And wear a proper mask properly when you are indoors around people who are not your family or in a crowded outdoor venue."
On the Mayo Clinic Q&A podcast, Dr. Poland shares the latest COVID-19 news and answers listener questions.
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