Bystanders can still save lives through Compression-only CPR:

The American Heart Association (AHA) now supports the use of compression-only cardiopulmonary resuscitation
(CPR) by untrained bystanders of witnessed cardiac arrest. Now bystanders can avoid mouth-to-mouth contact with a potential stranger but still provide potentially lifesaving help. Those who are unwilling to risk infection by performing mouth-to-mouth resuscitation may be more willing to perform chest compressions alone. Compression-only CPR is much easier for those whose CPR skills are stale, as the provider does not have to think how many compressions to ventilations should be performed, how long to allow between each breath, and how many cycles to perform. Compression-only CPR allows for more frequent compressions compared to traditional CPR, as there are no pauses for provision of breaths.

It is also easier for emergency dispatchers to instruct callers in how to perform compression-only CPR until emergency medical services (EMS) arrives, and it is easier to educate more laypersons about compression only CPR, potentially increasing the number of bystanders who could intervene in an arrest.

Watch the video for a graphical how-to.