The claim that antibiotics are ineffective against viral infections is common knowledge and scientifically established, as viral pathogens lack the cell walls and targets that antibacterial drugs affect. No formal citation is strictly required, though medical literature consistently confirms that prescribing antibiotics for viral respiratory infections is ineffective and constitutes overtreatment.
The claim states a fundamental biological fact that antibiotics (which target bacteria) are ineffective against viral infections (such as viral chest infections). This is a matter of everyday scientific observation and common knowledge, though multiple papers in the retrieved set (0, 1, and 8) explicitly support the premise that antibiotics are not indicated or responsive for viral respiratory tract infections.