British drugs giant GlaxoSmithKline has said that trials have shown one dose of its swine flu vaccine produced 'a strong immune response.'
"The results demonstrate that after one dose the candidate vaccine can provide a strong immune response," GSK said in a statement.
The trial, which is taking place in Germany, involves 130 healthy volunteers aged 18 to 60.
Chinese biotech company Sinovac has already obtained the green light from Chinese authorities to produce a one-dose vaccine.
And French firm Sanofi-Pasteur and CSL of Australia said last week that tests had shown vaccines they had developed were also effective in a single dose.