Dressed in a white and blue uniform, Yunior Perez, a 17-year-old student from Havana's 10 de Octubre district, was happy to catch up with his classmates at recess and see his teachers again in his school.

He was among the nearly 85,000 high school seniors in Cuba returning to the classroom on Monday after being vaccinated with Cuban-developed coronavirus vaccines.

"The virus is still around. Of course, we take some risks getting out of the house," said Perez, who was eager for schools to reopen.

"I was missing my school. Now, I want to study hard to get into the University of Havana next year," he said.

The gradual reopening of schools in Cuba has taken place across 12 of the country's 15 provinces and the Isle of Youth special municipality, as the Cuban government continues to ease coronavirus lockdown restrictions.

Students and teachers are provided with hand sanitizers, and face mask requirements and social distancing guidelines remain in place.

Cuba's educational authorities have postponed the reopening of schools in Pinar del Rio, Sancti Spiritus and Las Tunas, the three hardest-hit provinces amid a third wave of COVID-19.

Since the onset of the pandemic in Cuba in March 2020, schools have fluctuated between class learning and distance learning.

Cuban Education Minister Ena Elsa Velazquez stressed that following sanitary measures during the health emergency was indispensable to reducing the risk of the virus spreading in schools.

Students "who have not been vaccinated due to having contracted COVID-19 or other reasons can also attend schools," she told state TV.

On Monday, Cuba registered 4,272 new cases and 38 related deaths, taking the national tallies to 895,719 cases and 7,618 deaths, respectively.

The Caribbean nation has reported 19,074 COVID-19 pediatric cases in the last two weeks despite a decline in daily coronavirus cases.

Maria Elena Soto, a senior official at the Cuban Ministry of Public Health, said most high school seniors in Cuba have received a three-dose Cuban-made coronavirus vaccine.

"It is very important that students abide by coronavirus safety measures at school, public places and home. We urge parents to protect their children," she said Monday during a COVID-19 daily briefing.

By November, Cuba expects to vaccinate more than 90 percent of its 11 million population, including children and adolescents aged 2-18.