Vaccines, a matter of risk/benefit ratio
The vaccine history provides two main indications that are applicable to Covid-19. First, the whole killed vaccine is somewhat less potent than the bioengineered replicating ones, but has a broader antigenic spectrum. Therefore, it is the most promising one for dealing with virus variants. Finally, the possibility exists that an existing vaccine is active against Covid-19 as well.
Covid 19 is another chapter of the war that primordial forms of life, consisting of viruses and bacteria, have always fought against the human species. The primordial forms of life display an impressive replicative capacity, combined with an equally impressive ability to kill the opponent, in order to use the remaining carcass as a source of nutrition. The immune system is the only natural weapon for humans to defend themselves. It fights viruses and bacteria with humoral and cellular antibodies. They are exactly tailored on the single aggressor, to neutralize it without damaging the surrounding tissues. Furthermore, antibodies can be remodeled, to deal mutations responsible for the phenomenon known as resistance. Antibodies give to the organism a long-lasting immunity. This protective effect has some limits. The most important one is the relative slowness to achieve full activation. In fact, it takes from 3 to 4 weeks to become fully efficient, whilst a sick person can die and infect other people. Vaccines are the result of the scientific development, due to the necessity to “domesticate” infections by activating the immune system witho ...