Dengue Vaccine Gone Wrong?

A Dengue vaccine program was recently suspended in the Philippines due to concerns that the “vaccine could worsen the potentially deadly disease in people not previously infected.” The vaccine, known as Dengvaxia, has been given to over 830,000 children. It’s the first-ever approved dengue vaccine, produced by the French pharmaceutical company Sanofi. While it appears to be effective in people who have already had the virus, given the results of the study, the vaccine program has been suspended pending a review.

Dengue is an infection caused by mosquitoes. It’s a flu like illness found in tropical and sub-tropical climates and can be deadly. It’s the leading cause of serious illness and death among children in these areas. Infection rates have grown globally in recent decades and half the worlds’ population is at risk. Early detection and access to proper medical care dramatically lowers fatality rate.

Did a researcher foresee this problem?

Four decades ago, Dr. Scott Halstead, a leading figure in dengue research, first proposed that antibodies from an initial exposure to one of four types of the disease could increase the risk of a potentially lethal complication called severe dengue when a person was infected a second time, a process know as antibody-dependent enhancement or ADE.

This phenomenon could make development of a dengue vaccine tricky.

Rather than being protective, a shot given to someone who had never had dengue could act like a first infection, increasing their risk of severe dengue when they were exposed a second time.

 

Antibiotic Use on Farms Drops

In unexpected but good news, the FDA announced this week that antibiotic sales for use on farm animals has dropped 10% since they began collecting data in 2009. Overuse of antibiotics is a major contributor to antibiotic resistance, which is going to have life and death consequences for all of us (mostly on the death side). Farms use antibiotics to prevent animals from getting sick, and they also have the nice side effect of making animals grow faster, which means more meat eating and more money. Though the 2016 antibiotic sales numbers are still higher than in 2009, it is a step in the right direction.

According to a statement from Avinash Kar, a senior attorney at the Natural Resources Defense Council, “this course change provides a glimmer of hope that we can beat the growing epidemic of drug-resistant infections.”

Many large poultry company have made commitments over the past two years to reduce antibiotic use in chickens. Perdue Farms has led the way in this effort, and the vast majority of the company’s chickens now get no antibiotics at all.

Uganda Avoids Marburg Virus Disaster

Uganda has successfully contained an outbreak of Marburg virus, just weeks after it was first detected. Within 24 hours of being notified of the first confirmed death, the WHO deployed a rapid response team to the area:

Marburg is a highly fatal disease caused by a virus from the same family as that of Ebola. It can be transmitted from person to person by bodily fluids, and can cause bleeding, fever, vomiting, diarrhea and other symptoms.

This was the fifth outbreak of Marburg virus in a decade, and lessons have been learned from those outbreaks, as well as from the West African Ebola epidemic that killed more than 11,000 people.

Surveillance and contact tracing are critical in containing the virus:

“The response to the Marburg virus disease outbreak demonstrates how early alert and response, community engagement, strong surveillance and coordinated efforts can stop an outbreak in its tracks before it ravages communities,” said Dr Peter Salama, executive director of the WHO Health Emergencies Programme.

Dangerous Air Quality in California

Several years ago my mom sent me four giant boxes of N95 respirator masks. This was during the “swine flu” pandemic in 2009. I never wore them (but don’t tell her). Frankly, I thought I would look silly and believed any benefit was minor. Finally, after sitting in the far corner of a cabinet for years, there is a better use for them. Health officials are advising N95 respirator masks be worn in areas affected by the horrific fire outbreak this week.

Hospitals in Southern California have reported an uptick in patients with breathing problems, and are advising that people limit time spent outside, keep windows closed, and use air conditioners inside.

Santa Rosa, where devastating fires broke out in October, had the same air quality issues and recommendations:

The blazes create smoke waves — pulses of pollution containing everything from charred plastic residue to soot to other small particles that lodge deep in the lungs. They can trigger short-term ailments, such as coughing; worsen chronic diseases, such as asthma; and lead to long-term damage, including cancer.

The effect of the fires in Northern California’s wine country, which destroyed thousands of homes and killed 43 people, went well beyond the burn zone. The smoke choked the San Francisco Bay Area, home to 7 million people in nine counties, for days…

Even for healthy people, it can make breathing a miserable, chest-heaving experience. For the elderly, the young and the frail, the pollution can be disabling or deadly.

Health officials have advised that people in fire areas take precaution, even when smoke and ash can’t be seen or smelled.

Smoke Effects from the California Wildfires

The fires in California are heartbreaking and terrifying. Because I think there are enough hellscape fire photos already circulating, here is a smoke free photo of Ventura harbor on better days, plus a pelican. 

In addition to the completely unsettling feeling of not knowing if and when and where the winds will shift the fires to, there are a number of health effects that come from inhaling all that smoke. Wildfire smoke is a mixture of particles from burning vegetation, burning building materials, and anything else that’s burning.  According to the CDC, “wildfire smoke can make anyone sick. Even someone who is healthy can get sick if there is enough smoke in the air.” Inhalation can have immediate health effects, including coughing, asthma, chest pain, headaches, and more. People who are more likely to experience health effects include older adults, pregnant women, children, and people with preexisting respiratory and heart conditions.

So what can you do, besides sigh loudly in despair every few minutes? Limit your time spent outside, and keep your windows and doors closed. Other CDC recommendations:

Do not add to indoor pollution. When smoke levels are high, do not use anything that burns, such as candles and fireplaces. Do not vacuum, because vacuuming stirs up particles already inside your home. Do not smoke tobacco or other products, because smoking puts even more pollution into the air.

Run an air conditioner if you have one, but keep the fresh-air intake closed and the filter clean to prevent outdoor smoke from getting inside.

Do not rely on dust masks for protection. Paper “comfort” or “dust” masks commonly found at hardware stores trap large particles, such as sawdust. These masks will not protect your lungs from smoke. An “N95” mask, properly worn, will offer some protection. If you decide to keep a mask on hand, see the Respirator Fact Sheet provided by CDC’s National Institute for Occupational Safety and Health.

Also, keep an eye on your pets for breathing trouble. And remember that even if the air outside looks clear, it’s unlikely to be free from harmful particles.

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