Certificates are available after the first, second and booster dose of vaccine. The certificate is considered valid (when checked via the QR code it lights up green) 14 days after the Janssen vaccine dose or the second dose of any vaccine being administered in a two-dose vaccination scheme. The certificate after the booster dose becomes valid (i.e. lights up green) immediately. If you have been administered the second dose, only the certificate for the second dose is visible.
On December 21, 2021, the European Commission has per amendment to the Regulation stipulated a shortening of the validity of the certificates issued within the basis vaccination scheme (EU Digital COVID Certificate: Commission adopts binding nine-month period of recognition of vaccination certificates). They will remain valid for 270 days since the second (or, in case of the Janssen vaccine, first) dose. This measure does not apply to certificates issued after a booster dose. Please check the validity of your certificate on the MFA website, as not all countries of the world stick to the aforementioned document.
Vaccination certificates (first and second dose) are usually issued within a few minutes after vaccination (after a record of vaccination is ready in the ISIN OČKO system) at the vaccination point. However, within the validation app will it light up green only 14 days after the Janssen vaccine dose or the second dose of any vaccine being administered in a two-dose vaccination scheme. This does not apply to the certificate issued after the booster dose, such a certificate will light up green immediately.