Not just immunity but certain demographical factors are also responsible for causing Covid-19 re-infection in a person and one such predominant cause is unstable housing conditions, says a US-based study. A new study published in the journal Clinical Infectious Diseases suggests that people who don’t’ have suitable living conditions or are homeless are two-fold more vulnerable to re-infection with SARS-CoV-2 compared to the one who has a stable home.
Data assembled and analysed by the researchers of Boston Medical Center suggest that unavailability of stable housing is the only demographical factor that causes re-infection in many cases even with the presence of naturally acquired antibodies from the first infection. The findings also suggest that high levels of exposure to the infection can negate robust immune response. However, following Covid-19 guidelines can help prevent the risk of contracting infection repeatedly for individuals not having housing security.
The study was conducted to understand if demographical factors are responsible for SARS-CoV-2 infection or it depends only on the person’s individual response used the data of the ones who tested positive twice in a period of 90 days for SARS-CoV-2 in its study cohort.
Those who tested negative after 90 days after initial infection were classified as the convalescent group. None of the subjects were vaccinated as the data was collected before the vaccination programme kicked in.
The researchers subjected the infection and re-infection data to age, sex, comorbidities factors. Plasma from a smaller subset of patients from both cohort and convalescent groups was collected and tested for antibodies. Viruses from a few subjects from the first infection were sequenced with the virus of re-infection from same subject, to confirm re-infection.
The analysis showed only demographical factor associated with re-infection was the lack of a stable living environment. Moreover, no significant difference in antibodies was found between convalescent groups and individuals who tested positive or the cohort group, indicating that exposure to a high level of virus repeatedly can nullify the immune responses.
Manish Sagar, MD and Associate professor of Boston University School of Medicine that conducted the study finds that difficulty of the homelessness complying with Covid-19 health recommendation like wearing a mask or maintaining social distance results in ]increased exposure to SARS-CoV-2 causing re-infection.
Other components of the immune system that are important in the protection of SARS-CoV-2 reinfection are also under scrutiny. Moreover, understanding specific behavior of the homeless that makes them vulnerable to re-infection can help the government authorities in finding our potential mitigation strategies.
