Tropical travelers rejoice: researchers are getting closer to finding a possible vaccine for malaria, using genetically-engineered mosquitoes.
The Anopheles stephensi species is one of the main spreaders of human malaria. By altering its salivary glands, the mosquito acts as a “flying vaccinator,” carrying the Leishmania vaccine within its saliva. About 60 species of the Anopheles are vectors of the malaria parasite, which are transmitted to humans when the female feeds on blood.
Tests showed that when an altered mosquito bit its host — in this case laboratory mice — it became a transmitter of the vaccine. The bites succeeded in raising antibodies in the mice, indicating successful immunization with the vaccine.
It’s hoped that continuous exposure to bites will maintain high levels of protective immunity, through natural boosting, for a lifetime.
Researchers hope the vaccinator mosquitoes could be used to formulate a new strategy in the global fight against malaria. Every year about 250 million people are infected with malaria, and nearly one million die, according to the World Health Organization. In Africa, one in every five childhood deaths is caused by malaria.
There are, however, barriers to using this form of vaccination in the wild, including issues of controlling dosage, “medical safety issues” and the “issues of public acceptance to [the] release of transgenic mosquitoes.” It may not be as romantic as sundowners of gin and tonic (quinine is an old school anti-malarial), but it sure beats the potential side effects of Lariam.
If you’ve traveled to a tropical country, you’ve probably heard of Mefloquine. It is the most popular prophylactic against malaria, and is often sold under its trade name, Lariam. Lariam can have some serious side effects such as depression, anxiety, paranoia, nightmares and insomnia. You might say, “having nightmares is better than catching malaria and ending up in a hospital or worse.” I’m sure everyone would agree with that.
But when you wake up in a strange foreign land after a Lariam-induced nightmare…and you aren’t quite sure if you are really awake or if your waking state is just another extension of your dream, it can be pretty unnerving.
After such an experience, you might ask yourself if it is really necessary to ingest Mefloquine every time you enter a tropical region. I’ve known people who pop the little pills once a week when they are in Hong Kong or Singapore where the chance of catching malaria is akin to the chance that you will win the lottery. I guess some travelers choose to err on the side of caution when they enter any unfamiliar place.I haven’t even mentioned the host of shots and other pills that some guidebooks and doctors say you might want to consider. Typhoid is a big one. Cholera is another. Neither of these have vaccines that are 100% effective and they can bring about particularly nasty side effects. That doesn’t stop doctors from recommending them and people from getting the shots.
So what do you really need when you are traveling in a developing, tropical country? I guess it depends on how apprehensive you are. For me, Lariam and obscure vaccines are out unless I find that I am entering an area where a particular disease is truly a threat (see the WHO web site if you want to research a country you plan to visit). I also keep up to date on basic immunizations like tetanus and Hep B. And keep in mind, no matter how Lariam happy you get, there are diseases like SARS and H5N1 out there to remind us that health concerns are always going to be a scary part of traveling. And so I ask you, Gadling readers: what do you consider a necessary part of your travel-sized medicine cabinet?