The following persons holding licenses as required by RCW 70.05.050 shall be deemed qualified to hold the position of local health officer:

(1) Persons holding the degree of master of public health or its equivalent;

(2) Persons not meeting the requirements of subsection (1) of this section, who upon August 11, 1969 are currently employed in this state as a local health officer and whom the secretary of social and health services recommends in writing to the local board of health as qualified; and

(3) Persons qualified by virtue of completing three years of service as a provisionally qualified officer pursuant to RCW 70.05.053 through 70.05.055.