Risk Stratification of SARS-CoV-2 Breakthrough Infections Based on an Outbreak at a Student Festive Event

Abstract

In early 2022, the Coronavirus disease 2019 (COVID-19) remains a global challenge. COVID-19 is caused by an increasing number of variants of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Here, we report an outbreak of SARS-CoV-2 breakthrough infections related to a student festive event with 100 mostly vaccinated guests, which took place in Northern Bavaria, Germany, in October 2021. The data were obtained by retrospective guest interviews. In total, 95 students participated in the study, with 94 being fully vaccinated and 24 reporting infection by the delta variant. Correlation analyses among 15 examined variables revealed that time spent at the event, conversation with the supposed index person, and a homologous viral vector vaccination regime were significant risk factors for infection. Non-significant observations related to higher rates of infection included time since last vaccination, shared use of drinking vessels, and number of individual person-to-person contacts at the event. Our data suggest that a high rate of breakthrough infections with the delta variant occurs if no preventive measures are practiced. To limit infection risk, high-quality testing of participants should be considered a mandatory measure at gatherings, irrespective of the participants’ vaccination status.

COVID-19 Breakthrough Infections among Medical Students under the SLICE and CLARO Programs: Ateneo School of Medicine and Public Health Experience

“…This may not be the case in a student festive event in Germany where a study reported that increased time spent, conversation with an index person, shared drinks and person-to-person direct contact at the event contributed to increased infection despite having been fully vaccinated. 16 The increase in number of breakthrough cases observed in the months of August to October 2021 coincided with the Philippines' uphill trend of cases as seen in Figure 1 due to the Delta variant surge. 17 A similar trend in the increase in cases was observed in a study done among fully vaccinated and unvaccinated university athletes belonging to the U.S.based National Collegiate Athletic Association in August to September 2021 which coincided with the start of school semester and possibly due to the higher transmissibility and breakthrough infections caused by the Delta variant.…”

“…This may not be the case in a student festive event in Germany where a study reported that increased time spent, conversation with an index person, shared drinks and person-to-person direct contact at the event contributed to increased infection despite having been fully vaccinated. 16 …”