* receiving another covid-19 vaccine after inclusion in the study * receiving any vaccine 28 days after administration of a third dose of covid-19 (recombinante) vaccine. * refusal to sign the voluntary and informed consent form or refusal to permit collection of blood samples before the third dose of the covid-19 (recombinante) vaccine. * receiving any other vaccine 28 days before the inclusion in the study * previous vaccine schedule with other covid-19 vaccines, in the first and/or second dose. * covid-19 disease confirmed by rt-pcr (real time polymerase chain reaction) up to 28 days before inclusion in the study. * covid-19 symptoms up to 10 days before the inclusion in the study. * 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. * incapacitating mental illness * 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.

* receiving another covid-19 vaccine after inclusion in the study * receiving any vaccine 28 days after administration of a third dose of covid-19 (recombinante) vaccine. * refusal to sign the voluntary and informed consent form or refusal to permit collection of blood samples before the third dose of the covid-19 (recombinante) vaccine. * receiving any other vaccine 28 days before the inclusion in the study * previous vaccine schedule with other covid-19 vaccines, in the first and/or second dose. * covid-19 disease confirmed by rt-pcr (real time polymerase chain reaction) up to 28 days before inclusion in the study. * covid-19 symptoms up to 10 days before the inclusion in the study. * 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. * incapacitating mental illness * 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.

receiving another covid-19 vaccine after inclusion in the study receiving any vaccine 28 days after administration of a third dose of covid-19 (recombinante) vaccine. refusal to sign the voluntary and informed consent form or refusal to permit collection of blood samples before the third dose of the covid-19 (recombinante) vaccine. receiving any other vaccine 28 days before the inclusion in the study previous vaccine schedule with other covid-19 vaccines, in the first and/or second dose. covid-19 disease confirmed by rt-pcr (real time polymerase chain reaction) up to 28 days before inclusion in the study. covid-19 symptoms up to 10 days before the inclusion in the study. 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. incapacitating mental illness 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.

receiving another covid-19 vaccine after inclusion in the study receiving any vaccine 28 days after administration of a third dose of covid-19 (recombinante) vaccine. refusal to sign the voluntary and informed consent form or refusal to permit collection of blood samples before the third dose of the covid-19 (recombinante) vaccine. receiving any other vaccine 28 days before the inclusion in the study previous vaccine schedule with other covid-19 vaccines, in the first and/or second dose. covid-19 disease confirmed by rt-pcr (real time polymerase chain reaction) up to 28 days before inclusion in the study. covid-19 symptoms up to 10 days before the inclusion in the study. 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. incapacitating mental illness 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.