Ivermectin has some antiviral, some antibacterial, and some anti-inflammatory action. But isn't as far as I know the best for the latter two problems. And there are many other infective causes. Think of pneumonia as a symptom, the result of something that caused inflammation and fluid build up in the lungs: if it started from aspirating chicken soup or being exposed to toxic fumes, an anti viral isn't going to help. Most antibiotics are useless against fungus. And so on. If you have someone with a high fever and difficulty breathing, go to a doctor! Or at least an urgent care center.