2023 Author: Bryan Walter | [email protected]. Last modified: 2023-05-21 22:24
Influenza A viruses under an electron microscope
American scientists have found that seasonal influenza vaccination is significantly less effective for obesity than for normal body weight. The results of the work were published in the International Journal of Obesity.
Annual flu epidemics affect an average of 5 to 15 percent of the world's population. Currently, the most reliable method of preventing this disease is preventive vaccination. Obesity is an independent risk factor for complications of influenza, including hospitalization-related conditions and death, so vaccinations are highly recommended for overweight people. At the same time, the effectiveness of vaccination in such people has practically not been subjected to special study.
To fill this gap, researchers from Duke and North Carolina Universities and St. Jude Children's Research Hospital conducted a prospective observational study involving 1,042 people aged 18 years and older (the final analysis included 1022 participants). All were vaccinated with inactivated trivalent influenza vaccine prior to the 2013-14 and 2014-15 epidemic seasons.
The diagnosis of influenza and ARVI with influenza-like symptoms (possible influenza) was carried out on the basis of symptoms and laboratory tests, and the production of specific antibodies in response to vaccination was also assessed in the participants using the hemagglutination inhibition test (HAI).
It turned out that after vaccination with influenza or SARS with flu-like symptoms, 9.8 percent of obese participants fell ill versus 5.1 percent of normal weight volunteers. According to one of the authors of the work, Melinda Beck, this may be due to an insufficient response of T-lymphocytes, which provide antiviral immunity.
At the same time, the synthesis and functions of anti-influenza antibodies (seroconversion and seroprotection) according to the HAI data, a standard test of vaccination efficacy, were approximately the same in all study participants, regardless of body mass index and the presence or absence of the disease. This casts doubt on the diagnostic value of HAI in influenza vaccination, the authors write.
“Impaired cell function, despite sufficient antibody production, can increase the susceptibility of vaccinated obese people to influenza. Alternative approaches may be needed to protect these people from both seasonal infections and pandemics,”concluded study lead author Scott Neidich.
Previously, scientists found that vaccination of pregnant women against influenza almost halves the risk of having a still child, and also effectively protects their children from infection in the first six months of life. Influenza vaccination has also been shown to elicit a stronger immune response when given in the morning. In addition, computer modeling made it possible to find a target for an experimental drug on the influenza virus, the effect of which does not depend on the pathogen strain.
You can learn about why the flu inevitably causes seasonal epidemics, does not cause persistent immunity and is one of the most famous infections from our material.
