Mosquitoes Will Rule the Earth as Climate Change Expands Disease Vectors


Although many U.S. politicians insist on denying climate change, most scientists worldwide are believers. And the U.S. Centers for Disease Control and Prevention (CDC) even has a page describing concerns over climate change and the likelihood it will increase the risk of vector-borne diseases. Those include Lyme disease (increasing), West Nile virus (increasing), Zika virus (increasing), and malaria (increasing).

And, in fact, given the flooding and destruction caused in the Carolinas by Hurricane Florence, the CDC notes that mosquitoes and as a result, mosquito-borne illnesses, often increase after a hurricane. Although mosquitoes don’t typically survive the high winds of a hurricane, “Immediately following a hurricane, flooding occurs. Mosquito eggs laid in the soil by floodwater mosquitoes during previous floods hatch. This results in very large populations of floodwater mosquitoes.”

Generally, these are “nuisance mosquitoes” that don’t spread illness-causing viruses. The disease-carrying types, however, usually increase two weeks to two months after a hurricane.

Bruce Y. Lee, associate professor of International Health at the Johns Hopkins Bloomberg School of Public Health, writing for Forbes, says, “As Slomit Paz summarized in publication in the Philosophical Transactions of the Royal Society B: Biological Sciences, many mosquitoes like it hot and wet. This may sound dirty, because it is. When the temperature and humidity are higher, mosquitoes may not only feed more frequently but also reproduce more. They also may become infectious sooner after acquiring WNV (West Nile Virus).”

According to the CDC, about one in five people who are infected by WNV develop a fever and other symptoms. The rest show no symptoms. About 1 out of 150 infected individuals develop a serious, sometimes deadly, disease. Most who develop the disease have a fever, headache, body aches, joint pain, vomiting, diarrhea or rash. Most affected individuals recover completely, but fatigue and weakness often last for several weeks to several months.

In the rare cases where the disease is fatal, they develop central nervous system disorders such as encephalitis or meningitis. Symptoms of severe disease include high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness and paralysis. Although individuals over 60 years of age are at greatest risk, it can occur in people of any age. Individuals who are immunocompromised, or have cancer, diabetes, high blood pressure, kidney disease or have received organ transplants are at higher risk.

These diseases have not evaded the attention of biopharma. One of the companies leading the charge is Moderna Therapeutics, which focuses on mRNA vaccines to treat a number of diseases, including mRNA-1325 and mRNA-1893 for Zika and mRNA-1388 for Chikungunya. All three are currently in Phase I clinical trials. One of the Zika programs is funded by Department of Health and Human Services’s Biomedical Advanced Research and Development Authority (BARDA) while the mRNA-1388 program is funded by the U.S. Defense Advanced Research Projects Agency (DARPA).

In August, Emergent BioSolutions, headquartered in Gaithersburg, Maryland, inked a deal to buy PaxVax, based in Redwood City, California, for $270 million in cash.

PaxVax, which is majority-owned by an affiliate of Cerberus Capital Management, focuses on specialty vaccines against existing and emerging infectious diseases. As part of the deal, Emergent picks up Vivotif, the only oral vaccine licensed by the U.S. Food and Drug Administration (FDA) to prevent typhoid fever. Vivotif is licensed for sale in 27 countries.

Emergent also acquires Vaxhora, a vaccine against cholera, a vaccine candidate developed for the U.S. Department of Defense against Adenovirus 4/7 and clinical-stage vaccine candidates for the military for Chikungunya and other emerging infectious diseases. It will also take over PaxVax’ European-based cGMP biologics manufacturing facilities and about 250 staffers.

In May, the FDA granted PaxVax Fast Track designation for its vaccine to the Chikungunya virus. The virus spreads through mosquito bites and can cause large outbreaks, although not generally seen in the U.S. They have occurred in Africa, Asia, Europe, and the Indian and Pacific Oceans. In 2013, the virus was seen in the Caribbean for the first time. Cases were reported in 2016 and 2017 in the U.S., Italy and France. Symptoms include fever, joint pain, headache, muscle pain, joint swelling, or rash. The symptoms are compared to those of dengue fever and Zika.

In March, a research group at Yale University and from Hanyang University, South Korea, developed a potential new RNA therapy for West Nile Virus. The work was partially funded by grants from the National Institute of Health (NIH). Kumar and Yanyang University’s San Kyung Lee are co-founders of Signet Biotech.

Hawaii Biotech focuses on developing vaccines for numerous infectious diseases, including West Nile virus, Zika virus, malaria and Dengue fever. The company has received more than $6 million in annual funding in federal grant contract revenue from the U.S. Department of Defense and the NIH. Since its founding in 1982, the company has received almost $75 million in grant and contract revenues.

And on September 10, 2018, Montreal, Canada-based Cyclenium Pharma and Vienna, Austria’s Haplogen Bioscience GmbH were awarded the EUREKA label for their joint program for pan-flaviviral pharmaceuticals. EUREKA was established in 1985, and is an intergovernmental network of funding bodies and ministries in more than 40 countries. The project uses Cyclenium’s CMRT drug discovery platform and Haplogen’s flaviviral expertise to identify new drugs against dengue fever, Zika, West Nile, Japanese encephalitis and yellow fever viruses.

Yee summarized a 2015 study published in 2015 in Global Change Biology, writing, “They showed that the continuing trends of rising temperatures and changing precipitation patterns will foster further spread of WNB such as leading to WNV being established as far north as southern Canada and even northern British Columbia by 2080.”

Bottom line? Politicians might deny climate change, but disease-carrying insects and their pathogens aren’t—they’re exploiting it. There might be a joke there about the difference between politicians and disease-carrying parasites, but let’s not go there.

Click here to get the latest life sciences news straight to your inbox. Subscribe now to our FREE newsletters

Back to news