The vaccination campaign includes children as young as two with toddlers across the country scheduled to get the first of two shots starting on Thursday, Public Health Ministry official Doctor Maria Elena Soto said on Wednesday according to Reuters.
With this, Cuba becomes the first in the world under six years of age to be immunized en masse.
Cuba on Thursday will seek World Health Organization (WHO) approval of three locally produced COVID-19 vaccines including Abdala, Soberana-2 and Soberana Plus.
Cuba is the only country in the Caribbean to have developed its own vaccine against the virus. More than 65% of Cubans have currently received at least one shot and 37% have been fully vaccinated with three shots, according to the health ministry.
The country says its vaccines have an efficacy above 90% and initial results are similar to those of other top vaccines significantly reducing transmission, critical illness and death.
The vaccines are based on traditional technology used to vaccinate young children for decades, the Reuters report added.
Over the past week, Cuba averaged around 7,500 cases per day and nearly 80 deaths, down significantly from a month ago but still one of the highest rates in the world in terms of cases per 100,000 inhabitants. Around 20% of cases were recorded in people under 20 years of age.
The country is under oppressive US sanctions for decades.