LONDON: September 13, 2016:Public mistrust of vaccines is causing the outbreak of diseases like measles, according to researchers.
Scientists from the London School of Hygiene and Tropical Medicine, Imperial College London and the Saw Swee Hock School of Public Health in Singapore questioned 66,000 people across 67 countries to discover their views on whether vaccines are important, safe, effective and compatible with their religious beliefs.
People in southeast Asia showed the highest level of confidence in vaccines, with Africa second.
The survey comes as a major yellow fever vaccination program is under way in the Democratic Republic of Congo and Angola.
An outbreak of the disease has killed hundreds of people. The World Health Organization aims to vaccinate more than 15 million people in both countries.
“If everyone agrees to be vaccinated, we can eradicate yellow fever from our country,” said Mosala Mireille, one of the head doctors overseeing the program in Kinshasa.
Europe showed the lowest level of confidence, driven largely by France where 41 percent of the population questions the safety of vaccines.
Scares dent public confidence
Doctor Heidi Larson from the London School of Hygiene and Tropical Medicine says recent high-profile press coverage in France of vaccine scares has dented public confidence.
“Anxieties about links between Hepatitis B [vaccines] and multiple sclerosis several years ago, scientifically deemed unlinked, but still caused anxiety,” Larson said. “There still is today concerns about side effects related to the HPV vaccine, again not scientifically confirmed.”
Mistrust in France was also driven by the response to the H1N1 flu outbreak fears in 2009, when the government spent $1.4 billion on 94 million doses of the vaccine. The majority were sold off or destroyed.
Larson fears the consequences of that mistrust.
“We will get some combination of influenza strains that will be very fatal,” Larson said. “And if we have such poor compliance with a pandemic vaccine in the future, I would be very worried about that.”
Researchers warn that decreases in confidence can lead to people refusing vaccines, which in turn can trigger disease outbreaks. But the study found a high level of global support for vaccinating children against disease. (VOA)
Off the shores of Newfoundland, Canada, an ecosystem is unraveling at the hands (or pincers) of an invasive crab.
Some 1,500 kilometers (930 miles) to the south, the same invasive crab — the European green crab — is helping New England marshes rebuild.
Both cases are featured in a new study that shows how the impacts of these alien invaders are not always straightforward.
Around the world, invasive species are a major threat to many coastal ecosystems and the benefits they provide, from food to clean water. Attitudes among scientists are evolving, however, as more research demonstrates that they occasionally carry a hidden upside.
“It’s complicated,” said Christina Simkanin, a biologist at the Smithsonian Environmental Research Center, “which isn’t a super-satisfying answer if you want a direct, should we keep it or should we not? But it’s the reality.”
Simkanin co-authored a new study showing that on the whole, coastal ecosystems store more carbon when they are overrun by invasive species.
Good news, crab news
Take the contradictory case of the European green crab. These invaders were first spotted in Newfoundland in 2007. Since then, they have devastated eelgrass habitats, digging up native vegetation as they burrow for shelter or dig for prey. Eelgrass is down 50 percent in places the crabs have moved into. Some sites have suffered total collapse.
That’s been devastating for fish that spend their juvenile days among the seagrass. Where the invasive crabs have moved in, the total weight of fish is down tenfold.
The loss of eelgrass also means these underwater meadows soak up less planet-warming carbon dioxide from the atmosphere.
In Cape Cod, Massachusetts, the same crab is having the opposite impact.
Off the coast of New England, fishermen have caught too many striped bass and blue crabs. These species used to keep native crab populations in check. Without predators to hold them back, native crabs are devouring the marshes.
But the invasive European green crab pushes native crabs out of their burrows. Under pressure from the invader, native crabs are eating less marsh grass. Marshes are recovering, and their carbon storage capacity is growing with them.
Simkanin and colleagues compiled these studies and more than 100 others to see whether the net impact on carbon storage has been positive or negative.
They found that the ones overtaken by invasive species held about 40 percent more carbon than intact habitats.
They were taken by surprise, she said, because “non-native species are thought of as being negative so often. And they do have detrimental impacts. But in this case, they seem to be storing carbon quicker.”
At the Smithsonian Environmental Research Center where she works, the invasive reed Phragmites has been steadily overtaking a marsh scientists are studying.
Phragmites grows much taller, denser and with deeper roots than the native marsh grass it overruns.
But those same traits that make it a powerful invader also mean it stores more carbon than native species.
“Phragmites has been referred to as a Jekyll and Hyde species,” she said.
Not all invaded ecosystems stored more carbon. Invaded seagrass habitats generally lost carbon, and mangroves were basically unchanged. But on balance, gains from marsh invaders outweighed the others.
Not a lot of generalities
To be clear, Simkanin said the study is not suggesting it’s always better to let the invaders take over; but, it reflects an active debate among biologists about the role of invasive species in a changing world.
“One of the difficult things in the field of invasion biology is, there aren’t a lot of generalities,” said Brown University conservation biologist Dov Sax, who was not involved with the research. “There’s a lot of nuance.”
The prevailing view among biologists is that non-native species should be presumed to be destructive unless proven otherwise.
When 19 biologists wrote an article in 2011 challenging that view, titled, “Don’t judge species on their origins,” it drew a forceful rebuke from 141 other experts.
Sax said the argument is likely to become more complicated in the future.
“In a changing world, with a rapidly changing climate, we do expect there to be lots of cases where natives will no longer be as successful in a region. And some of the non-natives might actually step in and play some of those ecosystem services roles that we might want,” he said.
“In that context, what do we do? I definitely don’t have all the answers.” (VOA)