Brain organoid model shows molecular signs of Alzheimer’s before birth

In a model of human fetal brain development, Emory researchers can see perturbations of epigenetic markers in cells derived from people with familial early-onset Alzheimer’s disease, which takes decades to appear. This suggests that in people who inherit mutations linked to early-onset Alzheimer’s, it would be possible to detect molecular changes in their brains before birth. The results were published in the journal Cell Reports. “The beauty of using organoids is that they allow us to Read more

The earliest spot for Alzheimer's blues

How the most common genetic risk factor in AD interacts with the earliest site of neurodegeneration Read more

Make ‘em fight: redirecting neutrophils in CF

Why do people with cystic fibrosis (CF) have such trouble with lung infections? The conventional view is that people with CF are at greater risk for lung infections because thick, sticky mucus builds up in their lungs, allowing bacteria to thrive. CF is caused by a mutation that affects the composition of the mucus. Rabindra Tirouvanziam, an immunologist at Emory, says a better question is: what type of cell is supposed to be fighting the Read more

Moderna

COVID-19 vaccine-generated antibodies last at least 6 months

How long does COVID-19 vaccine-generated immunity last? New laboratory results provide a partial answer to that question.

Antibodies generated by a currently available COVID-19 vaccine declined over time, but remained at high levels in 33 study participants 6 months after vaccination, according to data published Tuesday in the New England Journal of Medicine.

The results could begin to inform public health decisions about COVID-19 booster vaccinations and how frequently people should receive them. In older study participants, antiviral antibody activity tended to decay more rapidly than in those aged 18-55.

From Doria-Rose et al (2021). Note that neutralizing antibody activity was (on average) higher at day 209 than on day 29, when the second vaccine dose was administered. It takes two weeks for the immune system to kick into high gear after the second shot.

Emory Vaccine Center’s Mehul Suthar, co-lead author of the brief report, said that the “correlates of protection” are not yet known from COVID-19 vaccine studies – that is, what levels of antiviral antibodies are needed to fend off infection. Other forms of immunity, such as T cells, could be contributing to antiviral protection as well.

He cautioned that the decay in antibody activity over time – not surprising in itself – may combine with increased prevalence of emerging SARS-CoV-2 variants that may allow viruses to escape the immune system’s pressure.

“Still, these are encouraging results,” Suthar says. “We are seeing good antibody activity, measured three different ways, six months after vaccination. There are differences between age groups, which are consistent with what we know from other studies.”

The findings come from analysis of samples from the Moderna mRNA-1273 phase I clinical trial, which began last year. Reports of clinical outcomes from Pfizer/BioNTech also indicate that their vaccine remains effective after six months.

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Posted on by Quinn Eastman in Immunology Leave a comment

The blind is off: Moderna COVID-19 vaccine study update

Amidst the tumult in the nation’s capital, a quieter reckoning was taking place this week for the Moderna COVID-19 vaccine clinical trial. Lab Land has been hearing from Emory-affiliated study participants that they’re finding out whether they received active vaccine or placebo.

For example, Emory and Grady physician Kimberly Manning, who had written about her participation in the Moderna study in a Lancet essay, posted on Twitter Tuesday. She discovered she had received placebo, and then was offered active vaccine.

After Moderna reported strong efficacy and an Emergency Use Authorization came from the FDA, this was going to happen at some point – the question was when and how. At the advisory panel hearing in December, there was some tension over whether to remove the blind immediately, as this STAT article describes:

“Companies have said that they feel an ethical obligation to deliver vaccine to placebo recipients; the FDA and experts at its advisory panel have debated whether this obligation even exists. Instead, they argue, offering vaccine to volunteers receiving placebo limits the quality of the data about the vaccine’s long-term efficacy and side effects.”

A plan to keep participants in the study under a blinded crossover design was floated, but not implemented. Some participants have said they sensed from the start, based on temporary unpleasant side effects, whether they had received active vaccine or placebo.

Posted on by Quinn Eastman in Immunology 1 Comment