inclusion criteria: 1. age ≥ 18 years 2. complete primary vaccination with cominarty (pfizer) or covishield (oxford/astrazeneca) vaccines, and at least one booster dose with cominarty (pfizer) or covishield (oxford/astrazeneca) vaccines. the last duration being at least 4 before the study duration. 3. adult in a healthy condition or with a stable health status if pre-existing medical history. 4. sign informed consent, be able and willing to make the assessment, be accessible by telephone or in person by the local study team and willing to remain in the study area for the duration of the study 5. for women of childbearing age: a highly negative sensitive urinary pregnancy test during the inclusion visit and use an effective contraceptive method.

inclusion criteria: 1. age ≥ 18 years 2. complete primary vaccination with cominarty (pfizer) or covishield (oxford/astrazeneca) vaccines, and at least one booster dose with cominarty (pfizer) or covishield (oxford/astrazeneca) vaccines. the last duration being at least 4 before the study duration. 3. adult in a healthy condition or with a stable health status if pre-existing medical history. 4. sign informed consent, be able and willing to make the assessment, be accessible by telephone or in person by the local study team and willing to remain in the study area for the duration of the study 5. for women of childbearing age: a highly negative sensitive urinary pregnancy test during the inclusion visit and use an effective contraceptive method.

inclusion criteria: age ≥ 18 years complete primary vaccination with cominarty (pfizer) or covishield (oxford/astrazeneca) vaccines, and at least one booster dose with cominarty (pfizer) or covishield (oxford/astrazeneca) vaccines. the last duration being at least 4 before the study duration. adult in a healthy condition or with a stable health status if pre-existing medical history. sign informed consent, be able and willing to make the assessment, be accessible by telephone or in person by the local study team and willing to remain in the study area for the duration of the study for women of childbearing age: a highly negative sensitive urinary pregnancy test during the inclusion visit and use an effective contraceptive method.

inclusion criteria: age ≥ 18 years complete primary vaccination with cominarty (pfizer) or covishield (oxford/astrazeneca) vaccines, and at least one booster dose with cominarty (pfizer) or covishield (oxford/astrazeneca) vaccines. the last duration being at least 4 before the study duration. adult in a healthy condition or with a stable health status if pre-existing medical history. sign informed consent, be able and willing to make the assessment, be accessible by telephone or in person by the local study team and willing to remain in the study area for the duration of the study for women of childbearing age: a highly negative sensitive urinary pregnancy test during the inclusion visit and use an effective contraceptive method.