By Nancy Lepid
(Reuters) – The following novels are a roundup of the latest scientific studies on coronavirus and efforts to find a cure and vaccine for the disease caused by the virus, Covid-19.
Lack of ‘naive’ T cells increases the risk of COVID-19 in the elderly
A low supply of specific types of immune cells in the elderly, which are crucial to fighting foreign invaders, could help explain their vulnerabilities to severe COVID-19, scientists say. When microorganisms enter the body, the initial “innate” immune response produces inflammation, not particularly traces of bacteria or viruses.
Within a few days, the more specific “adaptive” immune response begins to produce antibodies against the invader with T cells that either help in antibody production or seek out and attack infected cells.
In a small study published Wednesday in Cell, adaptive immunity was found to be better in mildly diseased Covid-19 patients, and in particular, had stronger T-cell responses to coronavirus.
People over the age of 65 were much less likely to have weakened T cell responses and generally had a poorly integrated immune response, said Shane Crotti, co-founder of the La Jolla Institute for Immunology, in a news release.
As we age, our supply of “naive” T cells decreases, he explained. In other words, we have fewer “inexperienced” T cells available to enable us to respond to new invasions. “Aging and deficiency of naive T cells may be associated with risk factors for failure to produce an integrated adaptive resistance response, resulting in increased sensitivity to severe COVID-19,” the researchers said. (https://bit.ly/3ks4FbG)
Antiseptic nasal sprays can help limit the spread of coronavirus
Preliminary research suggests that povidone-iodine-containing antiseptic nasal sprays may help prevent the transmission of new coronaviruses.
In the test tube experiments, a team of ear, nose and throat doctors found that povidone-iodine nasal spray inactivated the virus slightly in 15 seconds. The nasal sprays they examined are usually used to disinfect the inside of the nose before surgery. Researchers have noted that formulations designed for skin use are not safe in the nose.
They reported on Thursday in JAMA TOLERINGOLOGY – Head and Neck Surgery that they now use sprays before their patients intranasal procedures to reduce the risk of virus transmission in the air through the spread of drops and aerosols.
They instruct patients to perform nasal decontamination before coming to appointments, so as to “reduce intranasal viral load and … prevent the spread to waiting areas and other common areas.” However they warn that regular use of povidone-iodine may not be safe for some people, including pregnant women and patients with thyroid conditions. Large clinical trials have not yet proven that viral transmission is inhibited by intranasal povidone-iodine solutions, but “this study is already ongoing,” the researchers said. (https://bit.ly/2RGjMSm)
Not all COVID-19 antibody tests are the same
Some COVID-19 antibody tests are more reliable than others. But despite the best ones, reliability varies among patient subgroups, a new study suggests. Some tests look for IgM or IgA antibodies, the first antibodies produced by the immune system in response to an invader, which do not stay in the body for long.
Other tests – the most common type – look for IgG antibodies, which usually develop within seven to 10 days of the onset of symptoms and remain in the blood for some time after the patient has recovered.
In a study placed Wednesday on Medrexive ahead of a peer review, researchers analyzed data from 11,809 individuals whose COVD-19 was diagnosed to have highly rated tests to see how well the various antibody assays “recall” the patient. Happened.
The commonly used Aso, which looks for IgG, had a recall rate of 91.2%. IGA and IGM Assoz have set a recall rate of 20.6% and 27.3%, respectively, United Health Group co-founder Natalie Shells told Reuters. “Recalls vary significantly in sub-populations and over time of tests, with operations becoming relatively stable after 14 operations.” “The tests performed better for men versus women, for whites versus whites, and for individuals over 45 years of age.” Shells added that more research is needed to understand why this diversity occurs. (https://bit.ly/32FsiHD)
Open https://tmsnrt.rs/3a5EyDh in an external browser for Reuters graphic on vaccines and treatments in development.
(Reporting by Nancy Lapid; Editing by Bill Burkerot)
