Antivirals act in many ways to eliminate a virus, one of them being, blocking the interaction of the virus with host cells. One such interaction is initiated by Haemagglutinin-esterases (HEs). They are a group of viral envelope proteins that can cause the reversible attachment of the virus to host cells. HEs occur in influenza C, toro-, and coronaviruses, including SARS-CoV-2. A study of the crystal structure formed by the fusion of HE with host proteins was performed to show exactly how the HE binds to the host cell. It was found that in SARS-CoV-2, the HE-host protein binding causes the molecules to undergo radical steric changes and adopt opposite orientations leading to strong binding. This means, the virus can bind very strongly to the host cell and it cannot be easily detached again. But molecules can be developed/synthesized, that can block this interaction and thus prevent the virus from attaching to host cells so strongly. This will prevent viral RNA from entering the host cell and causing infection. This opens up potential avenues for the development of broad-spectrum antiviral drugs that can not only help with SARS-CoV-2 but also with other viruses that have similar HE-host cell interactions.