The Delta variant of SARS-CoV-2, the virus that causes COVID-19, greatly contributed to the average weekly number of COVID-19 cases in the U.S. being more than 300% higher this Labor Day weekend compared to this time last year according to data from John Hopkins University. Further, as reported by USA Today, daily deaths are almost twice as high and hospitalizations are up 158%. As Delta continues to sweep the country, other variants “of interest” are making headlines. Last month we reported on the Lambda variant and now the Mu variant is making headway in the U.S.

Mu variant in the U.S.

While Delta remains the “most concerning” variant, as described by the World Health Organization (WHO), last week the organization added the Mu variant to its list of variants “of interest.” To date, the Mu variant has been found in more than 40 countries, including the U.S. where it has been detected in 49 states. First detected in Colombia in January 2021, today it comprises approximately 40% of COVID-19 cases in that country. Last week, Dr. Anthony Fauci, the White House chief medical advisor, noted that, right now, the Mu variant is not considered an immediate threat but that “we’re paying attention to it.”

Is the Mu variant vaccine resistant?

Although it needs more study, the Mu variant is gaining heightened interest most likely due to its potential vaccine resistance. As reported by CNBC, “the variant contains genetic mutations that indicate natural immunity, current vaccines or monoclonal antibody treatments may not work as well against it as they do against the original ancestral virus, the WHO said.”

What causes viruses to mutate?

Viruses spread by making copies of themselves. In short, at some point there is going to be an error in a copy. Think of making thousands of copies of a document on a copy machine—eventually there will be a smudge here, a random line there. Some copies will not be identical to the original and, then, copies are made of those with variations.

Why do variants transmit so quickly?

As noted in Infection Control Today, current variants have a “propensity for aerosolization.” The current impact of aerosolization is addressed in an article by Dr. Kevin Kavanaugh who describes a recent report in the CDC’s Morbidity and Mortality Weekly Report (MMWR) which demonstrated aerosolization in schools. As Dr. Kavanaugh summarizes:

“A school outbreak was traced back to an unvaccinated, mildly symptomatic teacher who reportedly read unmasked to her 24 students who presumably were wearing masks. All students were unvaccinated because of age. All 5 students in the first row, closest to the teacher’s desk, acquired the virus. But 2 of the 4 students in the back row also acquired the virus. The attack rate in the first 2 rows was 80% and 25% in the back 3 rows. It is evident that the virus was aerosolized and stopping spread would require a distance much greater than 6 feet (let alone the 3 feet now recommended for school distancing).”

Mitigating the spread of aerosolized pathogens with upper room UVGI

As we’ve discussed previously, it cannot be understated just how much aerosolization has caused the spread of SARS-CoV-2. Moreover, public health authorities and experts consistently suggest the use of upper room UVGI to help mitigate that spread. Earlier this year a stellar panel of engineers and infectious disease experts—representing about “150 years of learning”— virtually gathered for a webinar to talk about the safety and evidence base supporting the use of upper air UV. Hosted by a consortium of leading institutions including the Harvard Kennedy School and Harvard Global Health Institute, the online presentation, Keeping Public Spaces Safe: Germicidal Ultraviolet Light for Air Sanitation During COVID-19, addressed “an urgent need for a digestible overview of the state of the science of upper room UVGI and how that can apply to the fight against COVID-19 and other future threats.” See what the experts said here.

As always, we are watching the progress of all variants and will update as new information becomes available. To learn more about Aerapy UV technology for infection control, contact us for a free UV consultation.