CDC Preparing Vaccine for New Swine Flu
- By BSTQ Staff
Despite only 29 human cases of the new strain of swine flu in the past two years, the Centers for Disease Control and Prevention (CDC) is preparing an H3N2 candidate vaccine, and clinical trials are being planned for this year.
The CDC is concerned about this virus because it contains an element seen in the pandemic 2009 swine flu strain, H1N1, which may make it more likely for the virus to spread from person to person. All 29 cases were infected with strains of H3N2 “that contained the matrix (m) gene from the influenza A H1N1 pandemic virus,” explained Dr. Joseph Bresee, from the CDC’s influenza division. “This m gene may confer increased transmissibility to and among humans, compared with other variant influenza viruses.” In addition, the virus appears to have become more active recently, with 16 of the 29 cases diagnosed in July. Of the 16 new cases, 13 arose in children. Studies indicate that children may be more susceptible to the infection than adults, as occurred during the 2009-2010 pandemic H1N1 flu outbreak, said Bresee.
Flu viruses commonly circulate in pigs, but they are generally different from those that spread to people. However, when someone comes into close contact with an infected animal, these viruses can sometimes spread to people. All of the recent 16 cases were among people who had direct contact with pigs. In 15 cases, contact happened at a county fair. “Swine influenza viruses have not been shown to be transmissible to people through eating or handling pork or other products derived from pigs. It is not a food-borne disease,” Bresee said.
No human-to-human transfer of the virus occurred in the more recent cases, Bresee said, although scientists did find evidence of limited human-to-human transmission in three cases in 2011. And, fortunately, sustained person-to-person transmission of the virus hasn’t happened yet. To prevent contracting this flu, the CDC advises people to limit their contact with swine and avoid contact with sick swine. People who have contact with these animals should take precautions such as washing their hands, not eating or drinking in areas with swine and controlling their cough.