Attaches the virus to cell receptors and thereby initiating infection. Binding of H protein to the receptor induces a conformational change that allows the F protein to trigger virion/cell membranes fusion (By similarity). Down-regulates human MCP/CD46 cell surface expression. Belongs to the paramyxoviruses hemagglutinin-neuraminidase family. Non-sialidase subfamily. Morbiliviruses hemagglutinins have no neuraminidase activity.