Can a shot in the deltoid stimulate mucus in the airways? The answer is "No" ... Then, how can vaccines be effective?
Vaccine Effectiveness Myth: A 30-year lie on misplaced vaccines
In matters of vaccines, more than anything else, the devil is in the detail.
Vaccine effectiveness can be very binary and complete failure is quite easy. The immune system being a sophisticated bio-software; sensitivity is very strong. Every detail, every step of the way, is key: the area of injection, the injection tool, the immune context of the patient, the schedule … Where and how you inject the product can make or break the entire vaccine effectiveness.