“I don’t believe its attainable,” the Professor of Pharmacy, who works with other researchers to simulate various Covid-19 outcomes, told DPA. 

Achieving Covid herd immunity – where a whole community is protected against the virus because the vast majority are immune to it – would require at least 85 percent of the population to either be recovered or vaccinated against the disease. 

Chancellor Merkel has said in recent weeks that she believes this figure should be higher among the over-60s – a segment of the population who are particularly vulnerable to hospitalisation and illness as a result of Covid. Among this group, at least 90 percent should be vaccinated.

At present, however, there are too few vaccinations happening each day in Germany, and not enough willingness to get vaccinated, to reach these figures, Lehr said.

READ ALSO: Should Germany bring in Covid restrictions for unvaccinated people only?

As of Monday, the proportion of fully vaccinated people in Germany lay just under the 50 percent mark, at 49.4 percent. The proportion of the German population who have had at least one dose, meanwhile, was 60.9 percent. 

While the vaccination rate shot up rapidly in May and June, the number of people getting first doses has been trailing off in recently weeks. On Sunday, only around 120,000 people were jabbed – barely a tenth of the some 1.3 million who were getting vaccinated at the height of Germany’s campaign. 

Researcher Thorsten Lehr: The number of people getting vaccinated has “declined massively” in Germany. Photo: picture alliance/dpa | Iris Maria Maurer

Government officials have been debating how to deal with the segment of the population who opt not to get vaccinated. At the weekend, Angela Merkel’s chief of staff, Helge Braun, floated the idea of vaccinated-only entrance to restaurants, cinemas and stadiums. 

Experts are also watching closely to see if the German Vaccination Commission (STIKO) will issue a general recommendation for 12-17 year olds to get vaccinated against Covid-19. 

While many believe this age group will be key to attaining herd immunity – and both Moderna and BioNTech/Pfizer are approved for over-12s – Stiko currently only recommends vaccination for teens with chronic illnesses or other vulnerabilities. 

READ ALSO: Unvaccinated children could jeopardise herd immunity, German health experts warn

The start of a fourth wave? 

Speaking to DPA, Thorstan Lehr also commented on the rate at which infections are currently rising in Germany. 

While the country saw the 7-day incidence of Covid infections dip to 4.9 per 100,000 people on July 6th, infections are now on the rise again and had reached 14.3 nationwide on Monday.

“Exponential growth is now fully in motion,” said Lehr. “And the figures are going to rise even higher.” By the end of September, Lehr believes the 7-day incidence per 100,000 people could reach 150. 

“So by then we would see the incidence increase tenfold,” he added. “You have to call that a new wave.”

READ ALSO: Fact check: Will Germany’s Covid incidence really reach 800 by October?

Vaccinations could help reduce infection rates, but the number of people getting vaccinated has “massively declined,” said Lehr.