Section 4 of the Principal Act is hereby amended by the substitution of the following subsection for subsection (1):
"(1) In this Act 'worker' means any person aged 15 years or more who has entered into or works under a contract with an employer, whether the contract be for manual labour, clerical work or otherwise, whether it be expressed or implied, oral or in writing, and whether it be a contract of service or of apprenticeship or a contract personally to execute any work or labour but does not include -
(a) a person who is employed by or under the State,
(b) a teacher in a secondary school,
(c) a teacher in a national school,
(d) an officer of a local authority,
(e) an officer of a vocational education committee,
(f) an officer of a committee of agriculture, or
(g) an officer of a school attendance committee.".