In a pandemic, there will be more in need of health care (increased demand) and a fixed or decreased supply of health care to be provided. Clearly, some sort of rationing must be decided by someone.
In a socialized healthcare system, where care is perceived as “free”, demand is also not limited by anything like prices. Supply of healthcare will also be reduced because the governing body will seek to “reduce costs” by limiting price (what the providers are compensated).
In a socialist healthcare system, like a pandemic, the same conditions of supply and demand exist, requiring rationing, withholding of care, and people dying as a result.