A multinational, phase 2, randomised, adaptive protocol to evaluate immunogenicity and reactogenicity of different COVID-19 vaccines in adults ≥75 already vaccinated against SARS-CoV-2 (EU-COVAT-1-AGED): a trial conducted within the VACCELERATE network

Table 2 EU-COVAT-1-AGED – Visit Schedule Part B

Visit number	1	2	3	4	5
Procedure	Screening, enrolment, baseline 4th dose	Immune response evaluation	Follow-up	Follow-up	End of study
Day ± window	0	14 ±2 days after 4th dose	3 months ± 3 days after 4th dose	6 months ± 3 days after 4th dose	12 months ± 3 days after 4th dose
Screening for eligibility
Informed consent^a	X
Demographics and medical history^f	X
Eligibility check	X
Baseline procedures
Concomitant medication review	X	X
Physical exam	X	X^b
Vital signs	X	X^b
Immunogenicity
Anti-RBD and anti-N IgG (ELISA)	X	X			X
Neutralising activity (wild-type)^c	X	X			X
Neutralising activity (VOC)^c	X	X			X
Cellular response (qPCR assay)^c	X	X
Biobanking^d	X	X	X	X	X
IMP administration
Vaccination^g	X
Safety
AE/SAE^e	X	X	X	X	X

AE adverse events, SAE serious adverse event
^aInformed consent must be obtained before obtaining consent for biobanking and secondary data use, and any other procedure to be undertaken.
^bWill be performed at visit 2 only upon SAE
^cSamples taken from all subjects, analysis performed in a subgroup only. Analysis will be performed in all samples if additional funding becomes available.
^dFor secondary use defined in informed consent; also optional at visit 1 and visit 2: at trial site and upon agreement of trial participant additional blood collection for biobanking of peripheral blood mononuclear cells (PBMC) as per informed consent
^eSolicited AEs are recorded by trial participant till Day 7 and records will be collected at visit 2 (Day 14) by trial staff and captured in eCRF; unsolicited AEs are recorded by trial investigator until the end of trial as described in this protocol
^fMedical history includes information on prior SARS-CoV-2 infection and COVID-19 disease if applicable; name of SARS-CoV-2 variant should be documented if known
^gAdministration of 4th vaccination dose after blood sampling for immunogenicity and cellular immunity during visit 1. Trial participant is observed for any adverse reaction for at least 15 min or according to standard of care upon vaccination

ISSN: 1745-6215