Inactivated vaccines are made from inactivated pathogenic microorganisms or their metabolites. After the virus grows and reproduces in cells, it loses its pathogenicity (inactivation) by adding chemicals, but it still retains its immunogenicity. Inactivated bacteria or viruses are purified by various methods, and then adsorbed with appropriate adjuvants to make vaccines. The advantage of inactivated vaccine is that it can directly cause immune response after entering the human body, can not grow and reproduce, and is relatively safe and stable, but it needs multiple injections to produce relatively strong immunity. Pertussis vaccine, diphtheria toxoid, tetanus toxoid mixed preparation, inactivated Japanese encephalitis vaccine, etc. Also belonging to this kind of preparation are genetically engineered recombinant antigen vaccines (such as hepatitis B virus vaccine).
Attenuated live vaccine is a vaccine prepared by artificially attenuated or nontoxic strains screened from nature. After the live attenuated vaccine is inoculated into human body, it will proliferate in a limited or short time in an appropriate tissue system, which is similar to the process of mild artificial natural infection, thus causing an immune response similar to infectious diseases, but it will not get sick. The advantages of live attenuated vaccine are that it acts in human body for a long time, requires less inoculation times and can produce relatively strong immunity. The disadvantage is that the attenuated live vaccine is unstable to heat, and it usually needs to be made into freeze-dried preparation, which is not convenient for storage and transportation. Oral live attenuated polio vaccine and live attenuated measles vaccine belong to this kind of preparation.
Viruses:
Hehe, this is the difference.