The outbreak of dengue fever in Latin America in the past three months is alarming due to its scale – one million cases in Brazil within weeks, a significant increase in Argentina, a state of emergency in Peru, and now in Puerto Rico.
This situation indicates a changing landscape for the disease. The mosquitoes that carry dengue thrive in densely populated cities with poor infrastructure, as well as in warmer and wetter environments – conditions that are expanding rapidly due to climate change.
Governments in Latin America have confirmed over 3.5 million cases of dengue in the first three months of 2024, compared to 4.5 million in all of 2023. Over 1,000 deaths have been reported this year. The Pan-American Health Organization warns that this could be the worst year for dengue on record.
The rapidly changing disease landscape requires new solutions. Researchers in Brazil have provided some good news with the announcement of a new dengue vaccine that offers strong protection against the disease with just a single shot.
While there are two existing dengue vaccines, one requires an expensive two-shot regimen and the other can only be given to those who have already had a dengue infection.
The new one-shot vaccine, developed by scientists at the National Institutes of Health in the United States, uses weakened forms of all four strains of the dengue virus. Instituto Butantan in São Paulo and Merck & Co. will produce the vaccine, with plans for regulatory approval and production starting soon.
However, the vaccine may not be available in time to address the current outbreak, and it may not be sufficient for the next one either, as dengue typically surges in cycles every three to four years.
Butantan will only produce the vaccine for Brazil, leaving other countries in Latin America to purchase it from Merck. The demand for a dengue vaccine extends beyond the Americas, as the disease spreads to new regions like Croatia, Italy, and California.
Dengue, also known as breakbone fever, can cause excruciating joint pain. While many infected individuals may not show symptoms, severe cases can lead to organ failure or shock.
Treatment for severe dengue can reduce mortality rates, but delays in seeking treatment can result in higher death rates. Children under 5 are particularly vulnerable in the current outbreak in Brazil.
Efforts to vaccinate against dengue in Brazil are underway, but challenges remain in achieving herd immunity. The high cost of vaccines like Qdenga presents additional barriers for widespread vaccination.
The race to accelerate dengue vaccine production is essential, given the significant economic and human toll of the disease. With multiple strains of the virus complicating vaccine development, the need for effective immunization strategies is more urgent than ever.
