The head of the UN children's agency, UNICEF, called Tuesday for teachers to be among those given priority access to the Covid-19 vaccines.

"The Covid-19 pandemic has wreaked havoc on children's education around the globe. Vaccinating teachers is a critical step towards putting it back on track," UNICEF chief Henrietta Fore said in a statement.

Teachers should be "prioritized to receive the Covid-19 vaccine, once frontline health personnel and high-risk populations are vaccinated," she said.

"This will help protect teachers from the virus, allow them to teach in person, and ultimately keep schools open."

According to UNICEF, at the peak of the first wave of the pandemic at the end of April, "school closures disrupted the learning of almost 90 percent of students worldwide."

Assuming that schools are not the main driver of community transmission, UNICEF said in its statement that unfortunately, classes currently remain closed for "nearly one in five schoolchildren globally -- or 320 million children."

We must "do everything in our power to safeguard the future of the next generation. This begins by safeguarding those responsible for opening that future up for them," Fore said.

"The consequences of extended, missed or impaired education are steep, especially for the most marginalized. The longer children remain out of school, the less likely they are to return, and the more difficult it is for their parents to resume work," she said.