Scientists working on a potential coronavirus vaccine have almost reached a breakthrough on an antibody treatment which could saves the lives of the elderly and vulnerable, it has been reported.

An injection of cloned antibodies which allows the body to counteract Covid-19 could prove hugely significant for those in the early stages of infection, according to British-Swedish pharmaceutical company AstraZeneca.

The company has already started to manufacture the Oxford University Covid-19 vaccine to ensure, if it does pass human trials, it can be made available in the autumn.

On Thursday, AstraZeneca signed a deal with the Coalition for Epidemic Preparedness Innovations (Cepi) to help manufacture 300 million globally accessible doses of the coronavirus vaccine candidate being developed by the Jenner Institute at the University of Oxford.

One member of the coalition is the Serum Institute of India, which The Sunday Telegraph reports is considering other “parallel” partnerships with AstraZeneca that may lead to the antibody treatment being funded as a stand-alone treatment.

AstraZeneca’s chief executive Pascal Soriot told the newspaper that the treatment being developed is “a combination of two antibodies” in an injected dose “because by having both you reduce the chance of resistance developing to one antibody”.

Antibody therapy is more expensive than vaccine production, with Mr Soriot saying the former would be prioritised for the elderly and vulnerable “who may not be able to develop a good response to a vaccine”.

It comes as trials of the potential vaccine have started in Brazil, a new epicentre of the pandemic, to ensure the study can be properly tested as transmission rates fall in the UK.

The Jenner Institute and the Oxford Vaccine Group began development on a vaccine in January, using a virus taken from chimpanzees.

Meanwhile, UK-based vaccine manufacturer Seqirus announced it is working in partnership with parent company CSL, CEPI and the University of Queensland to help develop a candidate Covid-19 vaccine in Australia.

Its manufacturing base in Liverpool is producing an adjuvant, an agent which improves the immune response of a vaccine.