Tracing the start of COVID-19 in GA

At a time when COVID-19 appears to be receding in much of Georgia, it’s worth revisiting the start of the pandemic in early 2020. Emory virologist Anne Piantadosi and colleagues have a paper in Viral Evolution on the earliest SARS-CoV-2 genetic sequences detected in Georgia. Analyzing relationships between those virus sequences and samples from other states and countries can give us an idea about where the first COVID-19 infections in Georgia came from. We can draw Read more

Reddit as window into opioid withdrawal strategies

Drug abuse researchers are using the social media site Reddit as a window into the experiences of people living with opioid addiction. Abeed Sarker in Emory's Department of Biomedical Informatics has a paper in Clinical Toxicology focusing on the phenomenon of “precipitated withdrawal,” in collaboration with emergency medicine specialists from Penn, Rutgers and Mt Sinai. Precipitated withdrawal is a more intense form of withdrawal that can occur when someone who was using opioids starts medication-assisted treatment Read more

CROI: HIV cure report and ongoing research

The big news out of CROI (Conference on Retroviruses and Opportunistic Infections) was a report of a third person being cured of HIV infection, this time using umbilical cord blood for a hematopoetic stem cell transplant. Emory’s Carlos del Rio gave a nice overview of the achievement for NPR this morning. As del Rio explains, the field of HIV cure research took off over the last decade after Timothy Brown, known as “the Berlin patient,” Read more

Omicron

Report on first Omicron case detected in GA

The first Omicron case detected in Georgia through SARS-CoV-2 genomic surveillance probably became infected during a visit to Cape Town, South Africa, according to a recent case report in Clinical Infectious Diseases.

The patient was a woman in her 30s, who was fully vaccinated with Pfizer/BioNTech twice, then a booster in October 2021 – about six weeks before becoming sick. She had a negative PCR test shortly before traveling back to Georgia but developed symptoms around the time of her return flight.

The woman was diagnosed with COVID-19 at the end of November, a few days after her return to Georgia — just after Omicron was declared a Variant of Concern by the WHO.

This single case report is not representative of the overall severity of Omicron, which is generating a large number of infections, burdening hospitals in Georgia and elsewhere. The patient experienced muscle aches, nausea, fatigue and cough, but did not have a fever or shortness of breath and did not require hospitalization.

A view of Cape Town’s Table Mountain

The lead authors of the case report were Marybeth Sexton, chief quality officer for the Emory Clinic, and infectious disease specialist Jesse Waggoner. The senior author was viral geneticist Anne Piantadosi.

The authors note: “Identifying this case required eliciting an appropriate travel history and being able to identify and perform sequencing for COVID patients in the community, since the patient had mild symptoms and did not seek clinical care.”

To speed detection of SARS-CoV-2 variants such as Omicron, the case report contains information about how to customize the “Spike SNP” PCR assay to give results within a few hours, rather than waiting for full viral sequencing taking 72 hours.

With the help of virologist Mehul Suthar’s lab, the authors were also able to report that the patient developed high levels of antiviral antibodies capable of neutralizing the Omicron variant. Currently available booster shots can elicit measurable antiviral antibody activity (see our recent post Thrice is nice), but actual Omicron infection generates way more.

Posted on by Quinn Eastman in Immunology Leave a comment

Booster COVID-19 vaccine vs Omicron: thrice is nice

A third dose of an mRNA COVID-19 vaccine is necessary to give someone robust neutralizing antibody activity against the Omicron variant, according to data from Emory researchers posted on the preprint server Biorxiv.

The findings support public health efforts to promote booster vaccination as a measure to fight Omicron, which is currently overwhelming hospitals around the world. They also explain why more breakthrough infections are occurring with the Omicron variant in people who have been vaccinated twice, and are in line with what other investigators have observed.

Compared with the 2020 Wuhan strain, the Omicron variant of SARS-CoV2 has more than 30 mutations in the viral spike protein, which is the primary target of neutralizing antibodies generated by vaccination. 

“Our findings highlight the need for a third dose to maintain an effective antibody response for neutralizing the Omicron variant,” says lead author Mehul Suthar, a virologist based at Emory Vaccine Center and Yerkes National Primate Research Center.

Vaccinated individuals who develop breakthrough Omicron infections are likely to experience less severe symptoms, and it is possible for Omicron to infect people even after receiving a booster, Suthar notes. Still, a majority of patients now coming into hospitals continue to be those who are unvaccinated.

In the preprint, Emory researchers tested blood samples from people who participated in Pfizer/BioNTech or Moderna vaccine studies in the laboratory for their ability to smother SARS-CoV-2 variants in culture. The preprint does not include clinical outcomes from infection, and also does not cover other aspects of vaccine-induced antiviral immunity, such as T cells.

In people who were vaccinated twice with mRNA vaccines, either Pfizer/BioNTech or Moderna, none showed measurable neutralizing antibody activity against Omicron six months after vaccination. But 90 percent displayed some neutralizing activity against Omicron a few weeks after a third dose.

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Posted on by Quinn Eastman in Immunology Leave a comment