Researchers cast doubt on the cost-effectiveness in some circumstances of screening people for prior dengue infection before immunizing them with Dengvaxia.
Dengvaxia (Sanofi Pasteur) is the first licensed vaccine against dengue, the mosquito-borne virus that causes approximately 9,000 deaths and an estimated 50 million to 100 million infections worldwide each year. Research has shown, however, that receiving the vaccine increases the risk for severe disease and hospitalization in patients with no prior exposure to the virus.
Based on these findings, WHO recommended that the vaccine be administered only to individuals who have serological confirmation of past dengue exposure.
To evaluate the impact and cost-effectiveness of serologic screening before administering Dengvaxia, Alex Perkins, PhD, Eck Family Assistant Professor of biological sciences at the University of Notre Dame, and colleagues simulated dengue transmission over 30 years, both with and without vaccination, under economic scenarios representative of Brazil and the Philippines.
“We found that public health impact depended primarily on the sensitivity or serological screening in high-transmission settings and on a combination of sensitivity and specificity in low-transmission settings,” they wrote.
Perkins emphasized the need for the serological screening to be as accurate as possible.
“Getting that wrong will lead to an increase in a person’s chance of experiencing severe disease if they get infected with dengue virus later on,” he told Infectious Disease News.
After examining cost-effectiveness from a public payer or individual perspective, the researchers determined that from a public payer perspective, vaccination following serological screening is unlikely to be cost-effective except in countries with relatively high gross domestic product and a low screening cost.
From an individual perspective, they predicted, vaccination following serological screening would potentially be cost-effective under a range of scenarios at slightly higher threshold cost, contingent on high specificity of screenings.
What does this mean for vaccinations in low-income countries? Perkins said decisions about whether to adopt this vaccine and how to go about distributing it are made at a national level.
“Different countries have different considerations that factor into making that decision,” he said. “In addition, though, there is the potential for individual people to decide to pursue vaccination with Dengvaxia.”
People electing to pursue vaccination on their own would need to consider how accurate the test is in determining whether they have been infected with dengue virus in the past. They would also need to consider how much they are willing to pay to potentially avoid dengue.
“Even with this vaccine, avoiding dengue is not a sure bet,” Perkins added. – by Caitlyn Stulpin
Disclosures: Perkins reports receiving research support from GlaxoSmithKline for unrelated work on dengue vaccines. Please see the study for all other authors’ relevant financial disclosures.