Yes, for all the combatants whose nations were signatories of the Geneva-conventions, and by extension their opponents.
Geneva Convention (1864)
Article 2 of the 1864 Geneva Convention provides: Hospital and ambulance personnel, including the quarter-master’s staff, the medical, administrative and transport services … shall have the benefit of the same neutrality [as military hospitals and ambulances] when on duty, and while there remain any wounded to be brought in or assisted.
Geneva Convention (1906)
Article 9 of the 1906 Geneva Convention provides: The personnel charged exclusively with the removal, transportation, and treatment of the sick and wounded, as well as with the administration of sanitary formations and establishments … shall be respected and protected under all circumstances. If they fall into the hands of the enemy they shall not be considered as prisoners of war.
Article 10 of the 1906 Geneva Convention provides:
The personnel of volunteer aid societies, duly recognized and authorized by their own governments, who are employed in the sanitary formations and establishments of armies, are assimilated to the personnel contemplated in the preceding article, upon condition that the said personnel shall be subject to military laws and regulations. Each state shall make known to the other, either in time of peace or at the opening, or during the progress of hostilities, and in any case before actual employment, the names of the societies which it has authorized to render assistance, under its responsibility, in the official sanitary service of its armies.