Barack Obama has stated that the US does not have enough information about the new experimental drug, to start treating the hundreds of people Western Africa who are inflicted by the Ebola virus.
"We've got to let the science guide us and I don't think all the information is in on whether this drug is helpful," Reuters quoted Obama speaking at the US-Africa Leaders' Summit, in Washington.
The US President also attributed the high casualty rate in West Africa to the poor health infrastructure in the countries.
"The Ebola virus both currently and in the past is controllable if you have a strong public health infrastructure in place," Obama said. "We're focusing on the public health approach right now, but I will continue to seek information about what we're learning about these drugs going forward."
Two US health workers, who contacted the disease while treating patients in West Africa, have been given the serum - called ZMapp - and seem to have been cured.
The move was initially criticized by the World Health Organisation (WHO) as they feel that the drug needs to be clinically tested amongst humans, before being used as a cure. However, with the Ebola death toll rising, the WHO ihas been now considering whether to go ahead with treating the sick in West Africa with the serum.
Onyenbuchi Chukwu, the Health Minister of Nigeria, has asked the US for ZMapp, to treat their Ebola patients.
Nigeria is the latest West African country to have recorded Ebola causalities, and has been looking to stamp out the virus before it spreads any further.
However, they are finding it quite difficult as the doctors in the capital city of Lagos have gone on strike.
Two people have been killed due to the virus in Nigeria, while five more have been tested positive. These five are being given treatment, in isolation.
However, according to the US Centers for Disease control and Prevention (CDC), the there are "no doses available" for mass use.