Dengue Vaccination

What is the dengue vaccine?

Dengue or dengue fever is caused by the dengue virus, which is transmitted through the saliva of the Aedes aegypti mosquito after it has fed on an infected person.

Dengue is non-transmittable, and a person can get dengue up to 4 times, once with each of the 4 serotypes of the virus, known as DENV-1, DENV-2, DENV-3, and DENV-4. Dengue fever can worsen and become life-threatening, especially with subsequent infections, and can prove to be fatal.

The dengue vaccine can help to protect against dengue fever. That said, it is still important to continue to take precautionary measures against mosquito bites, even after getting the vaccine.

How the dengue vaccine works

The dengue vaccine works by stimulating the immune system to produce antibodies against the dengue virus. If a vaccinated individual encounters the virus later on, these antibodies help deter or lessen the severity of the disease.

Types of dengue vaccines

In Singapore, only the Dengvaxia live attenuated tetravalent vaccine has been approved for use.

This dengue vaccine contains weakened versions of all 4 dengue virus serotypes (DENV-1, DENV-2, DENV-3, and DENV-4), and aims to trigger an immune response without causing severe illness.

Why do you need the dengue vaccine?

The dengue vaccine can help to protect individuals against infection. As dengue can sometimes be fatal, getting vaccinated is an important measure to take, especially if you have a past history of dengue infection.

When do you need the dengue vaccine?

Getting vaccinated against dengue is optional, and it is best for you to speak with your doctor to discuss your suitability for the dengue vaccine.

The Dengvaxia vaccine is only recommended for individuals aged 12 – 45 years who have previously been infected with dengue. This is due to concerns about an increased risk of severe dengue in those without prior infection.

It consists of 3 doses administered at 6-month intervals.

Who should not receive the dengue vaccine?

Those who should not receive the dengue vaccine include:

Children under 9 years old. They are less likely to have had a prior dengue infection, and the vaccine can potentially increase their risk of severe dengue if they haven't been exposed before.
People who have not had a prior dengue infection. This mainly applies to the Dengvaxia vaccine, which can increase the risk of severe dengue in those without prior exposure.
Pregnant and breastfeeding women. The safety of the vaccine in these groups is still not fully established, and it's generally recommended to avoid vaccination during pregnancy and breastfeeding.
People with severe allergies. Individuals with a history of severe allergic reactions to any vaccine component, including neomycin or a previous dose of the dengue vaccine, should not receive it.
People with weakened immune systems. This includes individuals with HIV infection, other immunodeficiency disorders, or those on medications that suppress the immune system. They might not have a strong enough immune response to the vaccine and may be at higher risk of complications.

How do you prepare for the dengue vaccine?

While there are no specific measures to be taken prior to receiving the dengue vaccine, you should inform your doctor beforehand if you:

Are pregnant, planning to become pregnant, or breastfeeding
Have received a blood or plasma transfusion or treatment with immunoglobins within the last 3 months
Have a compromised immune system, such as those who are HIV-positive
Are receiving chemotherapy or treatment that weakens the immune system
Are presently feeling unwell
Have recently received any other vaccine

What can you expect when getting the dengue vaccine?

The dengue vaccine is typically administered as an injection in the upper arm. After you get the vaccine, your doctor may ask you to stay for a few minutes to ensure you have no side effects.