The committee cited "insufficient data" over its efficacy for older people.
The European Medicines Agency is to decide on Friday whether to approve the vaccine for use across the EU.
The UK has been using the AstraZeneca vaccine in its mass immunisation programme for weeks now, and public health officials say it is safe and provides "high levels of protection".
The German announcement comes as the EU is in dispute with leading manufacturers over a shortage of vaccines on the continent.
UK-based AstraZeneca has said production issues at its Europe-based plants mean it will be unable to deliver the promised number of doses to the bloc.
But the EU says the firm must honour its commitments and deliver the jabs by diverting stock from the UK. It is calling on members to "make use of all legal means" to secure the supply.
Pfizer-BioNTech has also cut the number of doses it is delivering to the 27-member bloc.
