Vaccines have been in the headlines for the last few months here in the United States. This new FDA approved Pfizer vaccine is welcome news for worldly travelers.
Tick-borne encephalitis is endemic to rural outdoor settings in the former Soviet Union, Europe, and Asia. Various vaccines have been approved and widely used in these areas since 1976. Nearly 200mm doses given to-date with 95% efficacy, in fact. For the first time ever, the Federal Drug Administration has approved a tick-borne encephalitis vaccine in the United States. Given in a series of three shots, Pfizer’s TicoVac has been approved for use in ages of one year and older. U.S. travelers’ defense against tick-borne encephalitis has formerly relied heavily on methods of tick bite prevention. This includes use of repellents, like DEET, and wearing protective clothing when traveling to endemic areas.
What is tick-borne encephalitis?
There are three sub-types of tick-borne encephalitis – European, Siberian, and Far-Eastern. Unlike Lyme disease, this dangerous illness is not only contracted from the bite of an infected tick. While you can be infected by ixodid, or hard ticks, the family that includes the deer and brown dog tick, the disease is also passed through the consumption of raw dairy products from infected goats, sheep, or cows. Akin to Lyme, however, the infection originates in rodents on which ticks feed. What is also interesting about tick-borne encephalitis, is the way infection can be passed from adult ticks to tick eggs, and from larvae to nymph to adult ticks. For these reasons, medical communities abroad found that preventing the disease in humans is much more effective by way of vaccination.
Is tick-borne encephalitis like Powassan virus?
Both Powassan virus and tick-borne encephalitis are Flaviviruses, positive strand RNA viruses. Like tick-borne encephalitis, Powassan is passed to ticks from rodents, such as mice, squirrels, and groundhogs. Powassan symptoms can occur anywhere from two weeks to one month, whereas tick-borne encephalitis symptoms occur from 1 to 14 days. Both illnesses can result in meningitis or encephalitis. Both can cause permanent brain damage. Both infections can be lethal. Unfortunately, there is no vaccine or cure for Powassan virus – about 10% of patients, who contract the illness will die. And while we do not have tick-borne encephalitis in the United States, travelers to the Baltic region of Europe and Asia might feel better knowing they now have a 95% effective means of prevention. And for the time being, our biggest weapon against Powassan virus is personal tick protection and at-home tick control.
Learn more about tick-borne encephalitis on the CDC’s website here.