The government began administering second doses of the Russian Sputnik V coronavirus vaccine Tuesday after receiving another shipment of 300,000 shots at the weekend.
Argentina began its immunisation campaign on December 29 with the first 300,000 doses of the vaccine made by Russia's Gamaleya laboratory. It is prioritising healthcare workers in this first phase.
"The immunisation campaign has been developing in a timely fashion," Health Minister Ginés González García said.
The country of 44 million has recorded more than 1.8 million cases and almost 46,000 deaths from Covid-19.
Argentina was the first Latin American country, on December 23, to approve the "emergency use" of Sputnik V despite a lack of clinical trials.
The government has an agreement to purchase another 19.4 million doses by the end of February with an option for an extra five million.
Argentina has committed to buying 51 million doses in total and has also signed deals to purchase the AstraZeneca-Oxford and Covax vaccines, González García said Tuesday.
Negotiations are ongoing to procure the vaccine made by US pharmaceutical giant Pfizer with German biotechnology firm BioNTech.
The next stages of the immunisation programme will see the over 60s and people suffering from at least two illnesses receiving vaccines, the government confirmed.
Meanwhile, Chile began immunising its general population on Monday, starting with those over 80 or suffering from chronic illnesses.
Chile started immunising healthcare workers on December 24 and has signed deals to purchase 30 million doses.
It has reported 670,000 cases and 17,500 deaths amongst its 18 million population.