Handelsblatt economic daily had reported Monday that Berlin had estimated the efficacy of the jab among over-65s was just eight percent, citing unnamed sources.
Separately, Bild daily quoted anonymous sources saying that that Berlin did not expect the vaccine – developed with Oxford University and set to get the green light from the EU this week – would receive a licence for use in the elderly. It quoted an efficacy rate of “less than 10 percent”.
But Germany's Health Ministry said Tuesday it “appears that two things have been mixed up in the reports.”
“Around eight percent of the volunteers in AstraZeneca's efficacy studies were around 56 and 69 years old and three to four percent are above 70 years old,” said the Ministry.
“However, this does not mean that it is effective only in eight percent of older people,” it added.
The Health Ministry added that European regulator EMA will evaluate the effectiveness of the vaccine.
“It has been known since the autumn that fewer older people were involved in AstraZeneca's first studies than in other manufacturers',” it said.
The company had also rejected the German media reports as erroneous.
“Reports that the AstraZeneca/Oxford vaccine efficacy is as low as eight percent in adults over 65 years are completely incorrect,” the firm said in a statement late Monday.
“In November, we published data in The Lancet demonstrating that older adults showed strong immune responses to the vaccine, with 100 percent of older adults generating spike-specific antibodies after the second dose,” it added.
The UK became the first country to approve the two-shot vaccine on December 30th and did not impose an upper age limit. It has so far been vaccinating the elderly and healthcare workers for its immunisation campaign.
German Health Minister Jens Spahn distanced himself from the media reports, calling them “speculative”. He told broadcaster ZDF that he wanted to wait until data from the studies had been evaluated.
Based on scientific findings, he said, a decision would be made next week “as to which age groups would be vaccinated first with this vaccine”.
The reports came as the EU issued an angry warning to AstraZeneca Monday over its unexpected delay in delivering millions of doses of its Covid-19 vaccine to the bloc.
Last Friday, the pharma giant said it would not meet its contractual delivery commitments to the European Union because of unexplained “reduced yields” in its European supply chain.
The European Union has currently authorised two vaccines for widespread distribution, manufactured by BioNTech/Pfizer and Moderna.
It was set to add the AstraZeneca vaccine to that list this week, on the understanding that it would be already on hand and available for immediate roll-out.