The health secretary said the Government had taken the decision after the EU told the UK it would have to abandon its own more advanced procurement efforts in order to join the European scheme.
Mr Hancock added that joining the EU vaccine purchase scheme would mean the UK had no control over which vaccine was procured.
He told Times Radio: “We have chosen not to join the EU scheme on vaccine purchase. The reason is that it wouldn’t have allowed us to have a say in the vaccines that were procured, the price, the quantity, or the delivery schedule.
“We are further ahead than the EU schemes are. We would have joined the EU scheme if they had allowed us also to continue with our own negotiations, but one of the conditions of the scheme was that we would have had to stop our own negotiations and only do them through the European Commission and we weren’t prepared to do that.
“We think we will go faster this way.”
Mr Hancock added that the UK was already in talks with the ten leading vaccine development projects, including those at Oxford University and Imperial College London.
He said: “We think that, because we are further ahead, actually the risk would have been to stop the UK procurements and instead be required to buy only through the European Commission route.
“I think it is actually better to continue with the work that we have been doing, not least, because we have got two of the top candidates here domestically, countries around the world are keen to engage.”
Sir Tim Barrow, the UK’s ambassador to the EU, confirmed the decision in a letter to the European Commission, but added that the Government wanted to strengthen collaboration with the EU in other areas related to the vaccine.
He said: “This could include sharing of information on promising vaccine candidates; negotiations with vaccine manufacturers; vaccine trials; manufacturing investment and capacity building; mitigations to supply chain bottlenecks and other delivery risks such as global trade disruptions.”