Sanofi's Japanese encephalitis vaccine ad fuels fear

Pharmaceutical company Sanofi has come under fire for allegedly marketing its Japanese encephalitis vaccine Imojev, with an advertisement that fosters fear among consumers.

“When infected with Japanese encephalitis, the mortality rate is maximum 30 percent, and disability rate is up to 50 percent,” says some Sanofi ads attached to buses and other places. The vaccine is prescription-based medicine, but public advertisements are allowed for the sake of preventing endemics.

People exposed to the ad showed sensitive responses saying, “A bite by a red mosquito might kill me instantly, “I have known the mortality of Japanese encephalitis that high. I have to make extra care.”

Some medical experts, however, pointed out that although it may be necessary to keep people alert about Japanese encephalitis, it is excessive to promote its vaccine product by directly linking it to death. The phrase can mislead people, thinking they can get killed being bit by a mosquito and infected by its virus.

According to Centers for Disease Control and Prevention (CDC), people can be infected by the disease when culex tritaeniorhynchis bites them, but 95 percent of the infected people don’t feel any symptoms. Some suffer from light symptoms with fever and are rarely progressed to encephalitis. When they come down with the disease, 5-30 percent are dead, and 20-30 percent suffer from side effects. The incubation period is four to 14 days after a mosquito bites. Up to 30 percent fatality rate is based on statistics among the 5 percent of people who suffer from symptoms.

“You should not say ‘infection’ but ‘occurrence’ to be more precise because death results from the actual occurrence of the disease, not just infection,” said a professor at a university hospital in Seoul. “The ads itself may not be wrong, but the term is vague and exaggerated. As the ads are directed toward the general public, the company didn’t seem to take its scientific precision into account.”

He noted, however, it is necessary to keep people alert on the prevention and occurrence of Japanese encephalitis. “People with Japanese encephalitis may be dead or suffer from side effects, including mental disorder or loss of their motor ability. A vaccine is the only way to prevent because the disease isn’t curable”, the professor added.

CDC said the number of patients confirmed with Japanese encephalitis was 40 in 2015 and 98 percent of the patients were aged 40 or over (35 percent of them 30 or over, and 3 percent, 20 or older). The statistics compiled from 2011 to 2015 showed patients aged 40 or older accounted for 90.3 percent of the total.

There are two types of Japanese encephalitis vaccines; inactivated vaccine, the vaccine produced that kills Japanese encephalitis virus with heat or chemicals or slows down its activity, and live vaccine, the vaccine manufactured that reduces the toxicity of Japanese encephalitis virus.

People need to inject inactivated vaccine five times; the first and the second time of seven to 30 days interval during 12~23 months after birth; the third time during six to 12 months after the second shot; the fourth time at the age of 6; and the fifth time at the age of 12. As far as live vaccine is concerned, the first time should be during 12~23 months after birth, and the second time is one year after the first injection.