>>13969732>So if you used an attenuated virus, would it be less effective than mrna?Attenuated viruses are viruses that have been "taught" via evolutionary processes to infect an organism other than humans -- usually using chicken (eggs). By doing this, when the virus is introduced into the human body via the vaccination, it doesn't know how to properly infect the human cells and thus gets caught by the immune system before it has a chance to make significant progress. They are generally more effective as a vaccine as the immune system gets a look at the whole virus rather than just a fragment of it.
The problem is that such a virus is active and can, with enough time or sheer doo-dah luck, successfully infect an inoculated human and break the attenuation, thus becoming an active infection and using the vaccinated individual to infect other individuals. This is currently an issue with polio in Africa where they use attenuated virus vaccines -- vaccinated people are causing more infections than wild polio.
In the case of coronavirus, it readily infects animals and humans, has a very short incubation period and mutates rapidly, so making an attenuated virus that would stay attenuated would be very difficult. In reality, making a vaccine for a coronavirus is not a particularly effective method of combating it, the end result will be much the same as the flu shot where you take a yearly cocktail that might be anywhere from 0% to 60% effective against the dominant strain of the season.
