The NH Vaccine Registry is not mandatory. When you receive vaccines from a primary care provider, or when your children receive vaccines, you will either opt-in or opt-out of the immunization registry.
According to HB1606:
Each patient, or the patient's parent or guardian if the patient is a minor, shall be given the opportunity to opt-out or opt-in to the immunization registry. No patient’s personal data, such as name, address, date of birth, immunization, or vaccination information, shall be entered into the registry without the explicit, written or electronic consent of the patient, or the patient’s parent or guardian.
Note that this applies to immunizations and vaccinations generally, not specifically to ones related to recent events.
The Vaccine Registry needed to be modified in order to comply with the New Hampshire Right to Privacy.