At the upcoming BIO International Convention, vaccines experts will come together to discuss key infectious diseases for which preventive vaccines have eluded researchers. Panelists will discuss two “cold case” diseases where vaccines are currently in development. Panelists will share new information related to respiratory syncytial virus (RSV) and dengue fever vaccines. The panel will review the ‘lessons learned,’ the impact new technologies have had on conquering these diseases and examine the recent efforts to develop novel vaccines.
Not familiar with RSV and dengue fever? Below is a brief rundown of each disease.
RSV is a respiratory virus that infects the lungs and breathing passages. Most otherwise healthy people recover from RSV infection within a couple weeks. However, infection can be severe in infants, young children, and older adults. In fact, RSV is the most common cause of bronchiolitis (inflammation of the small airways in the lung) and pneumonia in infants in the U.S. In addition, RSV is more often being recognized as an important cause of respiratory illness in older adults.
By age two, almost all children are infected by RSV. For most, RSV results in a simple cold. But for some more vulnerable infants – such as those born prematurely and those with heart and lung problems – it can quickly progress from a low-grade fever, coughing, and difficulty breathing to life-threatening conditions.
RSV accounts for up to 1.7 million physician office visits, 400,000 emergency room visits, 125,000 infant hospitalizations, and about 500 infant deaths every year in the U.S. The estimated direct medical cost of RSV-associated hospital care is $750 million annually.
Symptoms of RSV infection are similar to other respiratory infections. A person with an RSV infection might cough, sneeze, and have a runny nose, fever, and decrease in appetite. Wheezing may also occur. In very young infants, irritability, decreased activity, and breathing difficulties may be the only symptoms of infection. Most otherwise healthy infants infected with RSV do not need to be hospitalized. In most cases, even among those who need to be hospitalized, hospitalization usually last a few days, and recovery from illness usually occurs with a couple weeks.
There is no specific treatment for RSV infection. A drug called palivizumab is available to prevent severe RSV illness in certain infants and children who are at high risk. The drug can help prevent development of serious RSV disease, but it cannot help cure or treat children already suffering from serious RSV disease and it cannot prevent infection with RSV.
More than one-third of the world’s population live in areas at risk for dengue virus infection, which is a leading cause of illness and death in the tropics and subtropics.
As many as 400 million people are infected yearly. Dengue is caused by any one of four related viruses transmitted by mosquitoes. Currently, vaccines are not available to prevent infection with dengue virus and the most effective protective measure is to avoid mosquito bites. Early recognition and prompt supportive treatment can substantially lower the risk of medical complications and death.
Dengue has emerged as a worldwide problem only since the 1950s. Although dengue rarely occurs in the U.S., it is endemic in Puerto Rico and in many popular tourist destinations in Latin America, Southeast Asia and the Pacific islands.
Dengue is a disease caused by any one of four closely related dengue viruses (DENV 1, DENV 2, DENV 3, or DENV 4). The viruses are transmitted to humans by the bite of an infected mosquito. It is estimated that there are over 100 million cases of dengue worldwide each year.
Dengue hemorrhagic fever (DHF) is a more severe form of dengue infection. It can be fatal if unrecognized and not properly treated in a timely manner. DHF is caused by infection with the same viruses that cause dengue fever. With good medical management, mortality due to DHF can be less than 1 percent.
The principal symptoms of dengue fever are high fever, severe headache, severe pain behind the eyes, joint pain, muscle and bone pain, rash, and mild bleeding (e.g., nose or gums bleed, easy bruising). Generally, younger children and those with their first dengue infection have a milder illness than older children and adults.
There is no specific medication for treatment of a dengue infection. Typical treatment is through the use of pain relievers with acetaminophen. As with dengue fever, there is no specific medication for DHF. It can be effectively treated by fluid replacement therapy if an early clinical diagnosis is made. DHF management frequently requires hospitalization.