Collection setOrder

Copy    public function setOrderByVaccDates($boxId, $direction = self::SORT_ORDER_DESC)
    {
        $case = 'CASE WHEN box_id = ' . $boxId . ' THEN vacc_date ELSE vacc_second_date END';
        $this->setOrder($case, $direction);
        return $this;
    }

CopyORDER BY 
  CASE 
    WHEN box_id = 376 THEN vacc_date ELSE vacc_second_date 
  END 
  DESC