A total of 370 jobs are to be announced today for counties Carlow and Cork.
Pharmaceutical company Merck Sharp & Dohme has announced it will create 170 jobs with a new vaccine facility in Carlow.
300 workers will also be employed in the construction phase of the €200m plant.
MSD Ireland (Biologics) Carlow joins MSD Ireland (Human Health) Dublin and MSD Ireland (Manufacturing) Tipperary as Merck Sharp & Dohme's third Irish facility.
The company's Irish operations are involved in the research, development, manufacturing and marketing of vaccines and medicines that address worldwide medical needs.
Willie Deese, Executive Vice President and President of Merck Manufacturing Division, said the company's decision to invest in Carlow represented an exciting new chapter in Merck Sharp & Dohme's Irish and global story.
'The vaccines and other products we will formulate in Carlow could ultimately be used by millions of people across the world which is a very exciting prospect.
'Despite challenging times globally, today illustrates that investment and enterprise is still very much alive and active,' he said.
Mr Deese commended the role played by the Government, the IDA and Carlow County Council and added:
'Ireland brings so many advantages for a company like ours - a pro-enterprise culture, a highly qualified and well-educated population, necessary support infrastructure and a record of success with projects of this scale and significance.
'These qualities influence investment decisions and these qualities are what made Ireland our destination of choice for this investment,' he said.
In Cork, one of the world's biggest hotel chains, Marriott International, is expected to announce details of a project which will lead to the creation of 220 jobs.
Marriott International operates more than 3,000 hotels worldwide.
The company already employs 160 people in Cork.
Many of its reservations and customer services are handled by multilingual call centres.
In 2002 the hotel chain established the European headquarters of its timeshare vacation club in Cork with the support of IDA Ireland.
160 people are currently employed at the call centre at the Cork Airport Business Park and this figure is projected to grow further.
Marriott International is understood to be impressed with the success of that operation and has been in negotiations to expand further in Cork.
