A certificate of membership shall be invalid if:

1. The certificate holder was ill at the time the certificate was procured;

2. Any person concerned in the procurement of the certificate had reason to believe that the illness existed at that time;

3. The illness continued to the death of the certificate holder and was a contributing cause of death;

4. Health questions were not asked on the application for coverage; and

5. The certificate holder died within sixty days from the date the certificate was issued.