New Vaccines in Development for International Travelers
Posted: Sep 14th, 2016 at 12:00AM
Someday in the near future, international travelers may have less to worry about on their trips. Currently, there are no vaccines to protect travelers from certain mosquito-borne illnesses that are common in many parts of the world. In recent months we can see how this can also affect us here in the United States as well with the Zika virus making its way into Florida.
The female Aedes aegypti mosquito is the carrier of Zika Virus, Dengue Fever, and Chikungunya, all of which currently do not have any vaccine to provide protection in the United States. This type of mosquito is common in much of the southern half of the United States, but is not currently infected with the viruses except for areas in Florida. The recent Zika scare in Florida has ramped up funding for development for a vaccine that can provide protection for travelers as well for people in infected areas right here at home.
Mosquito-borne illnesses are spread when a mosquito bites a person that is infected with the virus, becoming infected itself. The mosquito can then bite another person, infecting them. This is how the virus can spread from infected travelers into the mosquito populations in the United States.
Zika
Most people who are bitten by an infected mosquito with zika virus will have little or no symptoms of the disease. Other individuals however may develop fever, rash, joint pain, redness of the eyes, headache, or muscle pain. Most people will recover after a few days to a week. The real danger in zika virus is for pregnant woman. Zika virus has been shown to cause severe birth defects, mainly in the developing brain of the unborn child.
Zika vaccines are being funded and developed by multiple companies. Inovio Pharmaceuticals began clinical trails in June of 2016 and plans on starting a larger clinical trial in Puerto Rico soon. In August of 2016 the National Institute of Allergy and Infectious Disease also announce they would be starting small scale clinical trials on their newly developed Zika vaccine. Excivion recently received a grant to develop a Zika vaccine using technology that would allow the vaccine to be stockpiled by not needing refrigeration.
Dengue Fever
Dengue Fever is the leading cause of illness and death in the tropics and subtropics with more than 50-100 million infected each year, and more than a third of all people live in risk areas. Dengue is very rare currently in the United States, but is common in Puerto Rico, Latin America, Southeast Asia, and the Pacific Islands. Once bitten by an infected mosquito, the individual may experience high fever, headache, pain behind the eyes, join, muscle, and bone pain, rash, and mild bleeding. Serious cases can lead to excessive swelling into the abdominal cavity and lungs, shock, and death.
Sanofi, a French pharmaceutical company, has already released a vaccine called Dengvaxia into six countries. This vaccine has shown to reduce symptoms by 30% in people who have been previously infected with a strain on Dengue. However, this makes the vaccine much less protective for travelers who do not live in Dengue areas and have not been infected before as they are more likely to develop serious illness after a primary infection. The National Institute of Health is currently working on another vaccine that is starting Phase 3 clinical trials.
Chikungunya
Chikungunya is a virus that is found in mosquitoes primarily in Asia, Africa, Europe, and the Indian and Pacific Ocean, although the virus was found in the Caribbean in 2013. People who are infected typically experience fever and joint pain, but may also display headache, pain and swelling in muscles and joints, and rash. It is much rarer for a pregnant mother to pass on the Chikungunya virus to her child as it is for zika virus.
A vaccine for Chikungunya is well underway and has already shown promise after a Phase 1 clinical trial. Participants in the trial all developed antibodies against the virus without any notable dangerous side-effects. This is a very promising start, but more clinical trials are needed to test the vaccines effectiveness, safety, dosage, and scheduling before it can be released.
How to protect yourself
Until the vaccines are tested and made available to the public, travelers are advised to follow strict insect precautions when entering areas where infected mosquitoes are likely to be found. CDC recommends the following precautions to avoid mosquito bites.
- Wear long sleeves and long pants to cover exposed skin.
- Empty any standing water at home and in hotel rooms like buckets, pools and flower pots.
- Stay in places that are air conditioned. If not air conditioned, make sure to use mosquito netting over the bed at night.
- Use insect repellents containing DEET, picaridin, IR3535, and oil of lemon eucalyptus or para-menthane-diol.
- Spray clothing with permethrin or buy permethrin treated clothing.
Always visit a travel medicine clinic before international travels to make sure that you are up-to-date on insect and other precautions. A travel medicine specialist can let you know where specific outbreaks are occurring and what other precautions can be taken before, during, and after your trip to keep you safe and healthy.
