Mexico introduced on Friday a five-day closure of restaurants, cafes, bars, tourist attractions and public places in Mexico City and other town and cities to try and contain the spread of the disease.
The World Health Organization (WHO) on Saturday said the number of human cases of the swine flu virus A (H1N1) had risen to 615 from 365.
Although the illness has so far claimed few lives, the outbreak has sparked a number of dramatic media reports suggesting future death tolls "could" be in the tens of thousands or even millions.
The global health body also said well-cooked pork and pork products carry no risk of infection from the virus.
The head of Russia's Flu Research Institute said in an interview with RIA Novosti on Thursday that Russian scientists could create a vaccine to combat swine flu in three months.
