Is it acceptable to include only a concise sample informed consent in the protocol rather than both a standard and a concise one?
It is acceptable to use a concise consent form that meets all of the regulatory requirements found in 45 CFR 46.116 (i.e. all the required elements of informed consent must be included). The checklist is found at https://www.hhs.gov/ohrp/regulations-and-policy/guidance/checklists/index.html and this approach is acceptable as long as all the regulatory requirements are met.
Please also see the https://www.niaid.nih.gov/research/daids-clinical-research-protocol-informed-consent which references a few additional requirements.
Another option is to use a short form consent process, in which a summary of the required consent information is prepared and used for an oral presentation, but is not signed by the participant. Instead, a short consent document stating that the person has received the information is signed, per OHRP guidance at https://www.hhs.gov/ohrp/regulations-and-policy/guidance/obtaining-and-documenting-infomed-consent-non-english-speakers/index.html
Here is an excerpt from the OHRP guidance describing the short form:
Alternatively, §46.117(b)(2) permits oral presentation of informed consent information in conjunction with a short form written consent document (stating that the elements of consent have been presented orally) and a written summary of what is presented orally. A witness to the oral presentation is required, and the subject must be given copies of the short form document and the summary.