Reacción a "Reactions to the Health Minister's announcement that there will be a fourth dose of covid-19 vaccine "for the whole population"."

I do not know what evidence there may be to support this decision, as recently the WHO only recommended the fourth dose for vulnerable and older people. 

The immune response in healthy people is correct in published studies, especially in those with hybrid immunity, who have passed the infection and were vaccinated or vice versa, so an additional dose does not seem necessary.

In vulnerable people, with pathologies, immunodeficiencies, etc., a study could be made of their immune memory. This would allow a better definition of the groups and the need or not for a new dose.

Vaccine combination studies could be carried out. For example, Novavax and Hipra, which are recombinant. The vaccine against omicron seems to induce a response only for omicron and would not be useful for the other variants.

If the same vaccine is considered for further use, it does not seem to make much sense for the general population. Studies in Israel with a fourth dose show positive results, but only in the short term. After a few months the antibodies drop again.

In the case of vaccination with vaccines against Omicron, studies must first show whether it induces an improvement in the immune response in people already vaccinated or infected with the first variants. Some recent studies suggest that this may not be the case.