The nation is said to still be some way from being free of the virus that has infected 8,600 people and claimed over 3,500 lives there.
But the situation has 'improved significantly in recent weeks', according to Christian Aid.
The charity has told Premier the relief effort must now turn to support for those affected by the disease.
"Although the global response to the public health emergency was slow at first, the Sierra Leone government and international community have played a commendable role in the fight to contain the epidemic," said Christian Aid's Programme Manager for the Ebola Emergency Response, Alpha Sankoh.
He added: "At this critical stage in the recovery phase, Christian Aid urges them to prioritise the restoration of severely under-resourced primary healthcare systems and to invest in water and sanitation facilities, maternal and child health services, and vaccination programmes against preventable diseases."
Christian Aid is calling for social and economic support to be given to Ebola survivors, their families and hard-hit communities.
The charity has also said it will continue to train faith leaders to offer support to victims of Ebola, "they've had a crucial role," the charity's Jacopo Villani told Premier.
Christian Aid is now rolling out projects to refurbish 20 community health units, upgrading their water and sanitation facilities, with an emphasis on marginalised rural areas.
Alpha Sankoh said: "Sierra Leone's health system is extremely weak and there is a huge amount of work ahead to get to zero cases, to re-establish confidence in services and to ensure access to basic healthcare for those who desperately need it. Maternal and child health, immunisation programmes and malaria control must be prioritised.
"Poor water, sanitation and hygiene (WASH) conditions pose a critical challenge to the effectiveness of the Ebola response, especially in this transitional phase towards recovery.
"Christian Aid urges the Government of Sierra Leone, humanitarian agencies and donors to give primary attention to improving WASH conditions, especially in health facilities and schools in very poor rural areas and urban slum neighbourhoods."
Listen to Premier's Antony Bushfield speaking to Christian Aid's Jacopo Villani:
