European nations have been among the most successful in the world at getting their residents vaccinated against the novel coronavirus. Now, some will be among the first to dole out booster shots. The small but growing group that is planning additional shots for the fully inoculated includes some of the continent’s richest and most populous countries, potentially setting a precedent and marking a new phase of the vaccination campaign.

But as the coronavirus continues to infect and kill at alarming rates across the Global South, where vaccination levels remain catastrophically low, the decision by wealthy countries to give booster shots to their own people rather than donating those doses to poorer nations is deeply controversial.

Advocates and experts, including at the World Health Organization, have called the move immoral, and the European Union’s foreign policy chief criticized the bloc over “insufficient” vaccine shipments to countries in Africa and Latin America.

It fits into the pattern of decisions we’ve seen from wealthy countries since the beginning of the pandemic,” said Andrea Taylor, who is leading research at Duke University looking at global vaccine distribution. “The wealthy countries are going to allow their citizens to go through the buffet and get seconds while half the world is still starving.”

Those concerns have not stopped a handful of countries from moving ahead, and more may soon follow.

On Monday, Germany announced it would begin offering booster shots in September to the elderly, the immunocompromised and anyone who received a full regimen of the AstraZeneca or Johnson & Johnson shots, which may not be as highly protective as mRNA vaccines.

“We want to protect particularly at-risk groups as best as possible in fall and winter,” Germany’s health minister, Jens Spahn, said in a statement. “The risk of declining vaccination protection is greatest for those people.”