Only one dose of the vaccine, developed by scientists at the National Institute of Allergy and Infectious Diseases (NIAID) in the United States, was needed. “This study shows that delivering the vaccine directly to the respiratory tract can effectively protect primates from SARS,” said Dr Brian Murphy, a co-chief of the NIAID Laboratory of Infectious Diseases.
“With more research, we hope to develop a vaccine based on this approach that could be used to rapidly immunize first responders and other medical personnel, helping them control a potential outbreak,” he added in a statement.
The researchers, who reported their results in The Lancet medical journal, immunized four African green monkeys with the vaccine and four others with a control vaccine. A month later all the animals were infected with the SARS virus.
The monkeys given the SARS vaccine showed an immune response and none had evidence of the virus replicating but animals in the control group did.
“The finding is important since it brings together known yet innovative technologies, knowledge and skills to address prevention of an emerging infectious disease,” said Ruth Foxwell of the University of Canberra and AW Cripps of Griffith University in Australia, in a commentary in the journal.
Severe Acute Respiratory Syndrome (SARS) infected more than 8,000 people in nearly 30 countries and killed nearly 800 following an outbreak which first emerged in southern China in 2002, according to the World Health Organization (WHO).
It briefly re-emerged in China last April, killing one person and fueling fears that the disease could surface in an annual cycle similar to human flu.
The experimental nasal vaccine is the third candidate SARS vaccine developed by NIAID but the first to be delivered directly into the respiratory track – the main infection site.
“We now have three technologically unique approaches to restricting SARS replication in animals,” said NIAID director Anthony Fauci in a statement.
Earlier this month, the WHO said four volunteers in China were taking part in the first human clinical trials of a SARS vaccine which had previously been tested in Rhesus monkeys.