WHO warns mandatory vaccination 'absolute last resort'

"What is acceptable in one society and community may not be effective and acceptable in another," he pointed out.

Mandatory vaccination has become a hot topic in the EU, after Austria announced in November that it would make it shots compulsory for all citizens from February.

"Freedom means responsibility as well," said Austrian health minister Wolfgang Mückstein, during a meeting with his counterparts in Brussels, backing his country's decision as a strategic long-term response to tackle infections waves.

Germany and Lithuania are also considering this approach. Meanwhie, Covid-19 vaccines have become mandatory for health workers and other at-risk professionals in several counties – including France, Italy, Hungary, Latvia and Greece.

Athens has also announced mandatory vaccination for the elderly, who will face a €100-per-month fine from 16 January.

According to Greek health minister Thanos Plevris, 90 percent of the country's ICU beds are occupied by people over 60 and the non-vaccinated.

Meanwhile, countries such as Sweden or Spain have already positioned themselves against compulsory vaccination.

Making vaccination against Covid-19 mandatory "should remain a decision for individual member states" at this point, the Maltese health minister Christopher Fearne said.

However, he pointed out that the issue of mandatory vaccination might require a collective decision in the future.

Highest rates among children

Last week, European Commission president Ursula von der Leyen called for a debate on the issue given that over a third of the bloc's population is still unvaccinated.

According to the chief of the European Centre for Disease Prevention and Control, Andrea Ammon, "the current level of vaccine uptake in the EU is insufficient to limit the burden of Covid-19 cases and hospitalisation during the winter months".

On average across the EU, only 66 percent of people are fully-vaccinated – although there are strong variations between member states and age groups.

"It is not unusual today to see two-to-three times higher incidence among young children than in the average population," Kluge said on Tuesday.

Member states must consider the use of masks and ventilation, and regular testing, at all primary schools and as part of school protection measures. But child vaccination must be decided nationally.

The rollout of vaccines for children aged five to 11-years old is now expected to start next week in several EU member states.

EU health commissioner Stella Kyriakides called on EU member states to "close the immunisation gap," arguing that masks and social-distancing measures are still needed.

She added that booster doses should be considered for all adults, with priority for the elderly, the most vulnerable, and those above 40-years old.

'Not a question of doses'

The emergence of the new Omicron variant has also returned the focus to vaccine equality, since new Covid variants are more likely to emerge in low-vaccination regions.

The EU has donated 350 million doses to low- and-middle-income countries.

However, according to Italian health minister Roberto Speranza, "it is not a just question of doses".

"We need to do more to vaccinate the most fragile countries… allowing them to organise their own vaccination campaigns," he argued.

The difference between rich Western countries and African states remains massive. Fewer than 10 percent of people in Africa are vaccinated.

Omicron, first discovered in South Africa and Botswana, has so far been reported in over half of EU member states.