pragma solidity^0.4.21;

contract VaccineRegistration {

  address owner;
  address secondary;
  address tertiary;

  constructor(address _secondary, address _tertiary) public {
      owner = msg.sender;
      secondary = _secondary;
      tertiary = _tertiary;
  }

  modifier onlyOwners() {
      require(msg.sender == owner ||
        msg.sender == secondary ||
        msg.sender == tertiary);
     _;
  }

  string[] vaccines;

  function registerData(string _data) public onlyOwners {
      vaccines.push(_data);
  }

  function getData(uint _index) public onlyOwners view returns(string _data) {
      return vaccines[_index];
  }

}