Vietnam has the first vaccine for dengue fever

The dengue vaccine helps prevent dengue fever in both adults and children, curbing the spread of the Dengue virus and protecting public health.

What is the dengue vaccine?

The dengue vaccine is designed to prevent the infectious disease dengue fever in humans. The vaccine works by actively stimulating the immune system to produce immunity against the dengue virus strains that cause dengue fever.

Why should you get vaccinated against dengue?

Dengue fever is one of the most common infectious diseases in our country, with a tendency to spike during the rainy season and a risk of outbreaks. Dengue fever is caused by the Dengue virus, which has four serotypes: DEN-1, DEN-2, DEN-3, and DEN-4. The Aedes mosquito is the main vector for transmission.

Vaccination against dengue is essential because the Aedes mosquito, the disease vector, has a high reproductive capacity and lifespan. When it comes to laying eggs, a single female Aedes mosquito can produce between 100 to 200 eggs; under favorable environmental conditions, it takes only about 2 days for the eggs to hatch into larvae, approximately 7 days for the larvae to develop into pupae, and then into adult mosquitoes. Additionally, female mosquitoes live significantly longer than males and can transmit the virus to healthy individuals for up to 40 days.

Moreover, the environment and climate in Vietnam are highly conducive to the proliferation and development of this mosquito species. In simple terms, we are living in an environment teeming with dengue vectors that can bite us at any moment, transmitting the Dengue virus. Therefore, getting vaccinated against dengue is crucial to prevent the risk of infection.

Furthermore, the consequences of contracting dengue fever are considerable. Mild cases can lead to high fever, body aches, rashes, etc. In more severe cases, complications such as internal bleeding, organ failure, coagulopathy, sudden hypotension, or even death can occur if not treated promptly.

Thus, getting vaccinated against dengue can stimulate the body to produce specific antibodies, actively defending against the dengue virus types, significantly reducing the risk of infection and minimizing serious health consequences for individuals and the community.

Where is dengue fever common?

Based on the preferred living environment of the dengue-causing agent, the Aedes mosquito, we can identify regions where dengue fever is prevalent around the world, including Southeast Asia, India, southern China, the Middle East, Central America, South America, the Caribbean, Australia, Africa, and the Pacific.

Dengue fever is particularly widespread in certain territories of the United States and tropical climates of Southeast Asia, especially Vietnam.

In the United States, areas where dengue fever is common include Samoa, the Virgin Islands, Puerto Rico, and neighboring countries like the Marshall Islands, Palau, and the Federated States of Micronesia.

In Vietnam, dengue fever is highly prevalent in all four regions: the North, Central, South, and the Central Highlands. According to statistics from the Vietnamese Ministry of Health’s electronic portal, among dengue cases, those caused by the Dengue virus account for 85%, with 90% of fatalities occurring in patients under 15 years old.

It is evident that dengue fever transmitted by Aedes mosquitoes has become a significant “fear” within the community in Vietnam, not only affecting the health of infected individuals but also posing serious risks to their lives. Hence, we must remain vigilant against potential vectors of the disease and strictly adhere to recommendations for dengue prevention.

Who should get the dengue vaccine?

According to the WHO, individuals eligible for the dengue vaccine include children and adults, depending on the epidemiological situation and disease burden in each country concerning the severity of dengue in specific demographic groups, as well as data on the safety and efficacy of the dengue vaccine.

The WHO recommends that countries consider including the dengue vaccine in routine immunization programs in geographic areas where dengue transmission is high, posing a significant public health challenge. Many countries may have uneven geographic distributions of dengue transmission intensity and may consider targeting specific sub-national levels.

Additionally, there is insufficient data to make recommendations regarding vaccination for pregnant and breastfeeding women. Women of childbearing age can receive the dengue vaccine without needing to undergo pregnancy testing prior to vaccination.

Children and adults aged 4 – 45 should be vaccinated against dengue.

Who should not get the dengue vaccine?

• Individuals who are pregnant or planning to become pregnant within one month after vaccination.
• Nursing mothers.
• Individuals with congenital or acquired immunodeficiency, including those undergoing immunosuppressive therapy such as chemotherapy or high-dose systemic corticosteroids for a duration of two weeks or more (e.g., prednisone 20 mg/day or 2 mg/kg body weight/day) within four weeks prior to vaccination.
• Individuals with symptomatic or asymptomatic HIV infection with evidence of immune dysfunction.

How long does the dengue vaccine last?

As of now, the Centers for Disease Control and Prevention (CDC) in the United States predicts that the dengue vaccine may provide protection for at least 6 years. However, there is still a low risk that some vaccinated individuals may become infected or reinfected with dengue fever.

This information remains a prediction without scientific basis and has not been published; researchers worldwide are continuing to study and understand the duration of effectiveness of the dengue vaccine.

How many doses of the dengue vaccine are safe?

According to the World Health Organization (WHO), there are currently two types of dengue vaccines available worldwide, including:

Takeda’s dengue vaccine – from Japan, manufactured in Germany, has been authorized by the Vietnamese Ministry of Health for use in Vietnam since May 2024. It was first introduced in Vietnam and officially launched for nationwide vaccination on September 20, 2024, at hundreds of vaccination centers across the country. The Qdenga dengue vaccine is indicated for two doses spaced three months apart for children aged 4 years and older and adults, including those who have previously had dengue fever. The vaccine provides protection against all four dengue virus serotypes with an efficacy of over 80%, preventing hospitalization by up to 90%.

Sanofi Pasteur’s dengue vaccine, a leading pharmaceutical company from France, requires three doses spaced six months apart (0, 6, 12 months) following a clear vaccination protocol and strict monitoring system to ensure optimal vaccination effectiveness.

Dengue Vaccine (Takeda – manufactured in Germany)

This is a live attenuated vaccine developed and produced by Takeda Pharmaceutical Company from Japan, originating in Germany. As of August 2024, this vaccine has been approved in over 40 countries, including the European Union, the United Kingdom, Brazil, Argentina, Indonesia, Thailand, and Malaysia… In Brazil, Argentina, and Indonesia, it has been approved for use in national vaccination programs.

Takeda’s dengue vaccine is a specially formulated biological preparation designed to prevent dengue fever caused by the dengue virus. It offers protection against all four serotypes of the dengue virus, including DEN-1, DEN-2, DEN-3, and DEN-4, and is recommended for individuals aged 4 years and older. The clinical efficacy of the vaccine is over 80% in preventing dengue fever and helps to avert more than 90% of the risk of severe dengue, dangerous complications, and hospitalization. The vaccine is administered in a two-dose schedule, with the doses spaced three months apart.

Dengue Vaccine (Sanofi Pasteur)

This is the first licensed live recombinant dengue vaccine, recommended for a three-dose schedule with an interval of six months between doses, aimed at individuals aged 9–45 or 9–60 (depending on the regulatory approval of each country) living in dengue-endemic countries or regions. This vaccine requires individuals to undergo screening before vaccination to detect any prior dengue virus infection. Only those with a positive test result are eligible for vaccination. Due to the pre-vaccination screening requirement, this vaccine is not widely used.

Some Side Effects of Dengue Vaccination

Headache is one of the side effects after dengue vaccination.

For individuals who have previously had dengue fever, receiving the dengue vaccine may result in side effects such as itching or pain at the injection site, body aches, headaches, fatigue, lethargy, and discomfort. These side effects are completely normal signs that the body is reacting to the vaccine and building a protective mechanism against the virus. These side effects typically resolve within a few days after vaccination.

Like other vaccines, the dengue vaccine can also cause some serious reactions (very rarely), such as anaphylactic reactions. Therefore, individuals receiving vaccination should adhere strictly to the instructions of healthcare professionals.

Where Should You Get the Dengue Vaccine?

The dengue vaccine should be administered at reputable vaccination centers or healthcare facilities that comply with all requirements for administering this vaccine, including age, current health status, and having a post-vaccination observation area to minimize the risk of severe reactions.

The dengue vaccine is one of the essential tools in the global vaccination program aimed at reducing the spread of the disease, protecting lives, and alleviating the burden on healthcare systems, especially as dengue fever cases continue to rise in Vietnam.

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