Immunogenicity Study of the Covid-19 (Recombinante) Vaccine With a 4 or 8 Week Interval Between the First Doses.

Inclusion Criteria: * Availability to participate during the entire study, and ability to follow study protocol strictly. * Consent to supply personal contact information, such as telephone numbers, address and other information so the research team may contact the participant (For example, in case the participant fails to attend a scheduled visit without previous notice) * Ability to understand and sign the volunteered and informed consent form, and ability to fill in the adverse events journal at home, according to the evaluation of the principal investigator ou delegated research team members. * Understanding the impossibility of participating in another clinical trial while participating in this clinical trial. * Ability to fill out the adverse events journal at home Exclusion Criteria: * Pregnancy or puerperium * Having received any other Covid-19 vaccine any time before inclusion in the study * Having received any other vaccine 30 days before inclusion in the study * Covid-19 disease confirmed by RT-PCR (Real time polymerase chain reaction) up to 28 days before inclusion in the study. * Covid-19 symptoms during evaluation of inclusion in the study (Day 0). * Fever (Axillary temperature above 37,8 º C / 100,04 °F) 72 hours before vaccination in the study. * Contraindications to the Covid-19 (recombinante) vaccine - Fiocruz/AstraZeneca * Use of immunosuppressive medication, such as systemic corticosteroids or chemotherapy, or immunosuppressive diseases. We will consider as immunosuppressive doses of systemic corticosteroids daily doses of prednisone of 10mg or more, for more than 14 days. * Any discoveries made by the principal investigator that would enhance the risk of an adverse result following the participation in the study, or that in some other way justifies exclusion from the study.