No one even made the claim here that an effective vaccine would obviate the need for a drug.
In fact I very explicitly noted that a drug would be needed even if an effective vaccine was available (and explicitly noted that not all get vaccinated and that very few vaccines provide 100% protection).
The point was that an effective vaccine will seriously and very significantly reduce the market for a drug. For example, a vaccine that is 80% effective and used by 80% of the population would prevent AT LEAST 64% of infections, thereby reducing the market for the drug by 64%. But in reality it would reduce the market far more than that due to the effect of herd immunity. So in that example the actual reduction in the market would be far above 64%, likely close to 99% reduction (because with 80% vaccination of an 80% effective vaccine, if the ROI (in unvaccinated populations) was less than 3 (which is a pretty high ROI) then the disease would die out of the population almost entirely (because the new ROI would be less than 1).
For many diseases (with low ROIs) an effective vaccine would virtually eliminate (reduce by 99% or more) the market for drugs and for almost all the reduction would be at least on the order of 50%.
Given that, past statements that vaccines are not revelant to the discussion are indisputably wrong.
A very key point is that herd immunity will greatly increase the effect of a vaccine. One cannot possibly understand the economics and markets for either vaccines or drugs without understanding herd immunity (which also applies to drugs: in the case of drugs the herd immunity effect comes from those who were infected and survived and thereby are resistant to reinfection. It works very differently with drugs as it builds up slowly and has maximum effect only as the spread of a disease burns out. The herd immunity effect of survivors is why after an epidemic has burned out, there is always a percent of the population that never got infected. ALWAYS, except for diseases that do not leave a lasting immunity (RSV, and others)
