A close interaction between the virus SARS-CoV-2 and the
immune system of an individual results in a diverse clinical
manifestation of the COVID-19 disease. While adaptive immune
responses are essential for SARS-CoV-2 virus clearance, the
innate immune cells, such as macrophages, may contribute, in
some cases, to the disease progression. Macrophages have
shown a significant production of IL-6, suggesting they may
contribute to the excessive inflammation in COVID-19 disease.
Macrophage Activation Syndrome may further explain the high
serum levels of CRP, which are normally lacking in viral
infections. In adaptive immune responses, it has been revealed
that cytotoxic CD8+ T cells exhibit functional exhaustion patterns,
such as the expression of NKG2A, PD-1, and TIM-3. Since SARSCoV-2 restrains antigen presentation by downregulating
MHC class I and II molecules and, therefore, inhibits the T cellmediated immune responses, humoral immune responses also
play a substantial role. Specific IgA response appears to be
stronger and more persistent than the IgM response. Moreover,
IgM and IgG antibodies show similar dynamics in COVID-19
disease.
Prior to the onset of the pandemic, evidence on the conversion of regular rental housing into permanent holiday homes has fuelled concerns that Airbnb and other short-term rentals contribute to the shortage of affordable homes and to the displacement of regular residents in cities with high housing demand. When the pandemic set in, the media was quick to speculate that holiday homes would be returned to the regular rental market. This paper provides some theoretical reflections on the factors that are driving and impeding such a development and presents preliminary results from an ongoing research project that empirically tracesthe impacts of COVID-19 on the rental housing market based on an analysis of real estate listings in four large Austrian cities. We argue that a current shift to the regular rental market is likely, but that the medium- and long-term development is uncertain. Empirically, we demonstrate that such a shift has occurred in all four cities considered. We do not find evidence, however, that the increased rental housing supply has dampened rent levels.