Identification of the causal odds ratio in test-negative-design studies of COVID-19 vaccine effectiveness.

Delaunay, C.L., Nunes ,B., Monge, S., Lange, M. de, Túri, G., Machado, A., Latorre-Margalef,  N., Mlinarić, I., Lazar, M., Botella Rocamora, P., Erdwiens, A., Sève, N., Domegan, L., Martínez-Baz, I., Hooiveld, M., Oroszi, B., Guiomar, R., Sperk, M., Kurečić Filipović, S., Pascu, C., Linares Dopido, J.A., Dürrwald, R., Rameix-Welti, M.A., McKenna, A., Castilla, J., Hagen, C. van, Knol, M., Kaczmarek, M., Kissling, E. Identification of the causal odds ratio in test-negative-design studies of COVID-19 vaccine effectiveness. International Journal of Epidemiology: 2026. 55(2), art. dyag039. Letter to the editor.