Can I get a Dengue vaccine if I've never had Dengue?

If you have never had Dengue fever, your ability to get vaccinated depends heavily on where you live or are traveling. The most important thing to know is that your history of Dengue infection completely changes which vaccines are safe for you.

Currently, there are two main vaccines for Dengue fever, but they have very different rules about who can receive them:

Qdenga (TAK-003): Safe for First-Time Protection

Qdenga is a newer vaccine that is approved in many countries for people whether they have had Dengue before or not ^[1][2][3]. Research shows that it is safe and effective for individuals who are “Dengue-naive” (meaning they have never been infected) ^[2][3].

Because of this, Qdenga does not require you to take a blood test before getting vaccinated ^[3][4]. It has become an important option for travelers visiting places where Dengue is common ^[1].

Availability and Travel Planning:
It is important to know that while Qdenga is available in the European Union, the UK, and various Dengue-endemic countries, it is not currently approved in the United States ^[5].
Additionally, for those who can access it, Qdenga requires planning ahead. It is given as a two-dose series, spaced three months apart, so travelers need to start the process well before their trip ^[2][6].

Dengvaxia (CYD-TDV): Only for Past Infections

Dengvaxia is an older vaccine that is strictly for people who have already had Dengue fever at least once ^[7][3].

If you have never had Dengue, getting the Dengvaxia vaccine can actually be dangerous ^[7]. The vaccine can act like a “silent” first infection for your body ^[8]. If you are bitten by a Dengue-infected mosquito later on, your immune system may overreact in a way that makes the illness much worse—a phenomenon known as antibody-dependent enhancement (when antibodies from a previous infection or vaccine help the virus infect cells, leading to more severe disease) ^[7][8].

Because of this risk, the World Health Organization recommends, and regulatory agencies require, that anyone getting Dengvaxia must first pass a blood test confirming a past infection ^[3][4][9]. (Note: The manufacturer recently announced it is discontinuing the production of Dengvaxia, though some doses may remain available temporarily).

Who Cannot Get Either Vaccine?

Both Qdenga and Dengvaxia are live-attenuated vaccines, meaning they contain a weakened version of the virus ^[10][11]. Because they use a live virus, there are specific groups who generally cannot safely receive either vaccine, regardless of their past Dengue history:

• Pregnant women: Live vaccines are typically not recommended during pregnancy due to potential risks ^[10][11][12].
• People with weakened immune systems: Individuals who are severely immunocompromised (such as those undergoing certain cancer treatments or taking strong immunosuppressive medications) usually cannot receive live vaccines ^[11][13][12].
• Breastfeeding mothers: Data is limited, so caution is advised, and you should consult a doctor before getting a live vaccine while breastfeeding ^[12].

Vaccines Are Not a Replacement for Bug Spray

Even if you are able to get vaccinated, no Dengue vaccine provides 100% protection against the disease. It is crucial to continue using strict mosquito protection methods when traveling to an area with Dengue. This includes using EPA-registered insect repellent, wearing long sleeves and pants, and sleeping under a mosquito net if your accommodations are not air-conditioned or screened.

Next Steps for Travelers

If you are planning to travel to an area where Dengue is common, speak with a travel medicine specialist or your primary care doctor. They can help determine if a vaccine is available in your country, approved for your specific age (as age approvals vary by country), and appropriate for your health timeline.