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The price of stopping malaria: is eradicating mosquitoes ethical?

9 October 2018

“If you have a technology that has the potential to save millions of lives, then you need to think about the ethics of not using it.”

Scientists have created a ‘gene drive’: a piece of genetic code that stops female mosquitoes from producing eggs. They also manipulate the laws of inheritance so that almost 100% of offspring become carriers of the new gene, instead of the 50% that would naturally.

Professors James Miller and Peter Morris spoke to Good Morning Scotland about the pros and cons of this new form of gene technology with the potential to wipe out Anopheles gambiae, the breed of mosquito that spreads malaria.

A ‘moral obligation’

Given that the gene technology has the potential to save (human) lives – 445,000 people died from Malaria in 2016 alone – Professor James Miller felt it was a ‘moral obligation’ to eradicate the mosquito.

He also described a situation where the same technology could be used nefariously: bioterrorists could infect mosquitoes with viruses capable of spreading to humans. To Prof Miller, that qualified the need to eradicate the mosquito even further.

Asked if he could see people objecting to the culling of mosquitoes, Professor Miller responded,“It’s as likely as the world deciding, ‘Hey, the world is better off with smallpox’.”

The downsides of altering genes

Professor Peter Morris explained that experiments involving gene technology have only been used to eliminate a captive population of mosquitoes, so scientists don’t know for certain how it will work in nature.

“We do have to look at food chains; mosquitoes are food for fish, bats and birds. Also, male mosquitoes pollinate plants.”

As well as the risk of modified genomes crossing into related species of mosquitoes, Professor Morris said it could be difficult to measure the effect of altering the genes.

“You would effectively have to have a census of the mosquitoes to see if it was successful.”

Dr Andrew Hammond of Imperial College London was part of a research project that aimed to modify a mosquito’s genome in a way that made it spread over successive generations.

The modified ‘gene drive’ is passed on to nearly 100% of a mosquito’s offspring: it’s programmed to implant copies of itself into the other strands of its host’s DNA. This bypasses the usual law of nature where only half of the offspring would inherit the modified gene.

He claimed the entire mosquito population in Africa could be affected in a couple of years, meaning malaria could be eliminated in a relatively short space of time.