Severe COVID-19-related T cell deficiency in the elderly. Preservative sprays may limit the spread of the virus

Nancy Rapid

(Reuters)-The following is a summary of some of the latest scientific research on the new coronavirus and efforts to find cures and vaccines for the virus-induced disease COVID-19.

Lack of “naive” T cells increases the risk of COVID-19 in the elderly

According to scientists, the low supply of certain types of immune cells in the elderly, which is important for fighting foreign invaders, may help explain the vulnerability to severe COVID-19. There is. When bacteria enter the body, the first “congenital” immune response causes inflammation that is not targeted by bacteria or viruses.

Within a few days, a more accurate “adaptive” immune response will begin to produce antibodies against invaders, along with T cells that either aid in antibody production or seek and attack infected cells.

In a small study published at Cell on Wednesday, patients with COVID-19 with milder disease had better adaptive immune responses, especially T cell responses to coronavirus.

Shane Crotti, co-author of the Lahoya Institute for Immunology, said in a news release that people over the age of 65 are much more likely to have poor T-cell responses and poorly regulated immune responses.

He explained that as we grow older, the supply of “naive” T cells diminishes. In other words, fewer “inexperienced” T cells can be activated to respond to new invaders. “Naive T cell aging and deficiency may be associated with risk factors that fail to generate a coordinated adaptive immune response, resulting in increased susceptibility to severe COVID-19,” the researchers said. Stated. (Https://bit.ly/3ks4FbG)

Disinfectant nasal spray may help limit the spread of coronavirus

Preliminary studies suggest that preservative nasal drops, including povidone iodine, may help control the transmission of the new coronavirus.

In a test tube experiment, a team of ear, nose, and throat doctors found that a nasal spray of povidone-iodine inactivated the virus in just 15 seconds. The nasal sprays they tested are usually used to disinfect the inside of the nose before surgery. Formulations designed for use on the skin are not safe in the nose, researchers say.

They reported on Thursday at JAMA Otolaryngology-Head and Neck Surgery that patients would be required to use a spray prior to intranasal procedures to reduce the risk of viral infections in the air due to the spread of droplets and aerosols.

They also suggest instructing patients to perform nasal decontamination “to further reduce the viral load in the nasal passages and prevent their spread to waiting areas and other common areas” before coming to the promise. doing. However, they warn that daily use of povidone iodine may not be safe for some people, including pregnant women and patients with thyroid disease. “These studies are already underway,” the researchers said, although large clinical trials have not yet proven that viral infections are suppressed by intranasal povidone-iodine solutions. (Https://bit.ly/2RGjMSm)

Not all COVID-19 antibody tests are the same

Some COVID-19 antibody tests are much more reliable than others. But even with the best, reliability depends on the patient subgroup, and new studies suggest. Some tests look for IgM or IgA antibodies, which are the first antibodies produced by the immune system in response to an invader that do not stay in the body for long.

Other tests-the most common type-look for IgG antibodies. IgG antibodies develop within 7 to 10 days of the onset of symptoms and remain in the blood for some time after the patient recovers.

In a study posted to medRxiv on Wednesday prior to peer review, researchers analyzed data from 11,809 individuals diagnosed with COVID-19 in a highly evaluated test to infect patients. We saw how well the various antibody assays “remembered” what they were doing.

The most commonly used assay for IgG had a recall of 91.2%. However, IgA and IgM assays had estimated recalls of 20.6% and 27.3%, respectively, UnitedHealth Group co-author Natalie Sheils told Reuters. “Recall rates vary widely between subpopulations and depending on the timing of the test, and performance is relatively stable after day 14,” she said. “This test was better for men vs. women, non-whites vs. whites, and individuals over the age of 45.” Further research is needed to understand why these fluctuations occur. Sheils added. (Https://bit.ly/32FsiHD)

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(Report by Nancy Rapid, edited by Bill Berklot)