Do you actually know the profit margins for both ivermectin and the vaccine or are you just making it up?
Also, profit margin is irrelevant here, for at least two reasons. First, from the viewpoint of the producer, the vaccines are administered in multiple doses to as large a share of the population as possible, while ivermectin would only be prescribed for patients with severe covid, which is a much smaller share of the population. It’s a thousandfold increase in the quantity of medication sold.
Second, from the viewpoint of the consumer, the vaccine is free, and ivermectin costs money.