A recent study conducted by the University of Duisburg-Essen (UDE) has discovered possible causes for Covid-19 breakthrough infections, even in fully vaccinated individuals. The largest vaccine study in Germany involved over 2,500 employees of the University Hospital Essen, who were continuously monitored by the Institute of Pharmacogenetics and the Institute of Virology since spring 2021. Blood samples were taken after their first, second, and third vaccinations to determine the antibody titers against the virus. The study also recorded the general health status of the participants and any Covid-19 infections that occurred. The interim results, published in the journal Frontiers in Immunology, were based on data from 1,391 participants. Of these, 102 participants (7%) were infected with the Omicron variant of the virus between late November 2021 and early March 2022, despite receiving a booster shot.
According to Professor Winfried Siffert from the Institute of Pharmacogenetics, the good news is that all infected individuals experienced only mild symptoms, similar to a cold, and did not require hospitalization. The study found that the infected participants had significantly lower antibody titers compared to those who were not infected, indicating a weaker response to the vaccine. This was observed regardless of age, gender, or pre-existing conditions. The study is still investigating why the participants produced fewer antibodies. Additionally, the study examined the neutralizing ability of the antibodies, which describes how well the antibodies prevent the infection of cells. The researchers found that the blood serum of infected individuals had a significantly lower ability to neutralize the Omicron variant compared to non-infected participants. This is likely due to both the lower number and quality of antibodies produced.
The study’s findings shed light on the potential causes of breakthrough infections and highlight the importance of continued monitoring and research. The study also confirms that booster shots provide protection against severe illness, even in the event of breakthrough infections. The UDE study serves as a valuable contribution to the ongoing efforts to combat the Covid-19 pandemic.
