Tag Archives: Omicron

Omicron subvariants “of concern” drive surge in cases and reinfection rates

Photo courtesy of the National Institute of Infectious Diseases.

The COVID-19 story of the summer is omicron subvariants.

As of mid-July, two subvariants are “of concern,” according to the CDC: BA.4 and BA.5, which make up about 80% all COVID-19 cases in the U.S. Another variant, though it has yet to reach the status of “concern,” is BA.2.75, which is rapidly spreading in India and could become a threat in the U.S., according to virologists. (Omicron is the SARS-CoV-2 variant that emerged and swept the globe beginning November 2021, causing a big wave in cases, hospitalizations and deaths globally.)

How much the public should worry about these variants is a matter of debate among public health experts. See this July 13 story in Business Insider, quoting four infectious disease experts I have contacted frequently over the past two and half years. Three of the four experts (Amesh Adalja, M.D., Celine Gounder, M.D., Katelyn Jetelina, Ph.D., M.P.H., and Preeti Malani, M.D.) ranked the risks — on a scale of 1 to 10 — of between 0 and 7 depending upon age, health status and geographic location. One wouldn’t rank the risk because the data isn’t clear.

Some researchers, including Eric Topol, M.D., are extremely concerned because the variant is so contagious.

Continue reading

Understanding the CDC’s updated quarantine and masking guidance

Rochelle Walensky, M.D., M.P.H.

On Dec. 27, the CDC significantly shortened isolation and quarantine times for people who have tested positive for the SARS-CoV-2 virus or have been exposed to someone with the coronavirus.

CDC director Rochelle Walensky, M.D., M.P.H., said the decision to decrease isolation and quarantine periods was based on both the known science about the coronavirus’s transmission and the expectation that surging cases could cause societal disruptions.

“CDC’s updated recommendations for isolation and quarantine balance what we know about the spread of the virus and the protection provided by vaccination and booster doses,” she said. “These updates ensure people can safely continue their daily lives.”

However, the CDC’s decision was met with confusion and mixed reactions among infectious disease experts.

For example, Ashish Jha, M.D., M.P.H., dean of the Brown University School of Health wrote on Twitter that it is “a step in the right direction,” while Michael Mina, M.D., Ph.D., epidemiologist, raised concerns that a large number of people may still be contagious five days after testing positive and therefore shouldn’t be leaving isolation.

Continue reading

How to cover Omicron and other COVID variants of concern

Creative rendition of SARS-COV-2 virus particles. (Photo courtesy of the NIH Image Gallery via Flickr)

Much of the post-Thanksgiving media coverage has focused on Omicron, the SARS-CoV-2 virus variant detected circulating in South Africa and labeled a variant of concern (VOC) by the World Health Organization on Nov. 26. The other variants of concern are Delta, Alpha, Beta and Gamma.

WHO added Omicron to the VOC list based on available evidence, including the fact that the variant contains more than 30 mutations in the spike protein, the primary antigen that all WHO’s approved COVID-19 vaccines rely on to evoke an immune response. These mutations are all distinct from the genome of the ancestral (original) virus discovered in Wuhan in late 2019, and many of them already exist in the Delta and Alpha variants.

Some of these mutations have the potential to make the virus more transmissible (like Delta does), cause more severe disease or reduce the effectiveness of vaccines that prevent COVID-19 disease (like Beta does). However, there isn’t enough clinical evidence (real-world evidence from actual infections) to say yet whether the Omicron strain is more transmissible, more pathogenic, or less susceptible to protection from the vaccine.

Journalists should therefore keep in mind that the science of the variant is still evolving and report stories with the caveat that there remain a lot of unknowns, a normal aspect of the scientific process. The public is going to have to wait for more definitive information. Anthony Fauci, M.D., chief medical advisor to President Biden and head of the National Institute of Allergy and Infectious Diseases told Biden on Nov. 28 that he expects it will be another two weeks until scientists have more definitive answers. That feels like an eternity in COVID-time, and it’s okay to acknowledge that, but it’s also warp speed in real-science time, which is also important to keep in mind and convey to readers.

In the meantime, nothing changes the Centers for Disease Control and Prevention’s advice for protecting oneself and others from COVID-19: get vaccinated, get boosted, wear a mask indoors in places with people outside your household, avoid large indoor crowds and get tested if you have symptoms.

“We still have no scientific updates on Omicron’s impact on immunity escape or transmissibility,” wrote Katelyn Jetelina, an epidemiologist with the University of Texas Health Science Center in a blog post.  “If you’re hearing anything right now…it’s purely speculation. Hypotheses are important to discuss, but not the solid evidence we need. Getting answers takes time because good science takes time. I give it a week or two until the evidence starts rolling in.”

Continue reading