BERLIN — An outcry is brewing in Germany as thousands are set to be revaccinated after a nurse admitted to injecting patients with saline solution instead of a coronavirus vaccine.

Almost 9,000 people who may have received bogus shots in the spring will be offered new vaccinations, Friesland District Administrator Sven Ambrosy said at a news conference Tuesday.

The nurse, who has not been publicly identified, had initially admitted to giving six patients shots of saline solution after suspicions were raised in April. She said she did so to cover up the fact that she had dropped a vial of the Pfizer vaccine, German television channel NDR reported.

However, since antibody testing was carried out, a much wider group of people is suspected to have been affected. Police have also discovered that the woman, who worked with the Red Cross, had shared vaccine-skeptical posts on social media, NDR said.

Local authorities said they do not know how many of the 8,577 people who could have been affected were not given a real vaccine, but advise that all of them get revaccinated as a precaution.

Those who received the shots are all older than 70, German media reported — making them more vulnerable to covid-19, the disease that has killed more than 91,000 people in the country.

Police investigator Peter Beer said at a news conference that there was a “reasonable suspicion of danger” and cited witness statements.

Many expressed shock about the situation, including Ambrosy. “I am totally shocked by this episode,” he wrote on Facebook. He said officials would work to ensure that such an incident would never happen again in the Friesland district.

On Twitter, others branded the health-care worker as “dangerous,” and said that her actions were “appalling.”

This is not the first incident in which vaccine injections went wrong. Earlier this year, a 23-year-old Italian woman was mistakenly given six shots of the Pfizer vaccine by a distracted nurse who officials said “had an attention lapse.” The woman who was given the high volume of vaccine was closely monitored at a Tuscany hospital but did not have any adverse reaction, health authorities said.

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