{"id":12649,"date":"2026-10-30T11:51:50","date_gmt":"2026-10-30T10:51:50","guid":{"rendered":"https:\/\/webszh.uk-halle.de\/digihero\/?p=12649"},"modified":"2026-11-11T16:39:45","modified_gmt":"2026-11-11T15:39:45","slug":"new-publication-on-the-transmission-of-sars-cov-2-within-households","status":"publish","type":"post","link":"https:\/\/webszh.uk-halle.de\/digihero\/en\/2026\/10\/30\/new-publication-on-the-transmission-of-sars-cov-2-within-households\/","title":{"rendered":"New Publication on the Transmission of SARS-CoV-2 Within Households"},"content":{"rendered":"\t\t
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The University Medical Center Halle reported the following in its press release:<\/strong><\/p>

The risk of becoming infected with the Omicron variant within a household is approximately 20% shortly after vaccination or infection and increases steadily to around 80% over the course of one year. This is demonstrated by a recent study conducted by the University Medical Center Halle, based on data from 662 individuals collected during the second half of 2022. The findings, published in the scientific journal Infection<\/em>, also indicate that the risk of transmission within households was lower among children and adolescents, when the initially infected person experienced mild symptoms, and when preventive measures were implemented.<\/p>

With the end of the COVID-19 pandemic, the Omicron variant became dominant worldwide and is now considered an endemic pathogen. At that time, only a limited number of studies had investigated how the risk of infection within one’s own household changes over time following vaccination or infection. Furthermore, these studies were based either on negative test results or retrospective analyses.<\/p>

„No previous study had taken household circumstances into account while prospectively examining blood antibody titers, vaccinations, and infections over time. To address this knowledge gap, thousands of people across Germany agreed to participate in our DigiHero study and immediately notify our research team whenever an infection occurred,“ explain the study’s first authors, Bianca Klee and Sophie Diexer.<\/p>

The two research associates at the Institute of Medical Epidemiology, Biostatistics and Informatics at the University Medical Center Halle analyzed a valuable dataset comprising nearly 1,200 individuals from several hundred households.<\/p>

A total of 662 participants from 262 households were included in the analysis, 122 of whom were children. Approximately two-thirds had received at least three vaccine doses, while 12% had not been vaccinated at the time of infection.<\/p>

Participants were required to live in a household with at least two people and to collect a dried blood sample immediately after an infection occurred, using a study kit provided to them. A second sample was collected six to eight weeks later, once the acute infection had subsided.<\/p>

In the meantime, volunteers documented additional details about their infection and its progression within the household using a symptom diary and an online questionnaire. The research team then determined coronavirus antibody titers in the blood samples collected during the second half of 2022 through laboratory testing.<\/p>

Protection Declined Significantly Within One Year<\/h3>

Approximately 58% of household members became infected following the initial infection within the household, with an average delay of three days. The risk of transmission was lower when the initial infection was associated with only mild symptoms.<\/p>

The longer the time elapsed since the previous infection or vaccination, the more likely a subsequent infection became. The risk increased steadily over the course of one year and was similar following vaccination and previous infection.<\/p>

When vaccination or a previous infection had occurred recently, the risk of transmission was approximately 20%. After six months, household members became infected in one out of every two cases. After one year, the risk had increased to 80%.<\/p>

Differences in Transmission Risk Between Children and Adults<\/h3>

„Our data show that, within our study population, children and adolescents were less likely than adults to introduce the initial infection into the household. They also had a lower probability of transmitting or acquiring an infection.<\/p>

For children and adolescents, the risk of infection within the household was likewise approximately 20% shortly after vaccination or a previous infection. However, over the course of one year, this risk increased to only around 40%.<\/p>

Nevertheless, we were only able to include a relatively small number of children in the study, meaning that these findings are subject to greater uncertainty. However, they are consistent with previous investigations involving variants other than Omicron,“ explains Klee.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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