TIME Healthcare

Joan Rivers’ Death Raises Questions About Outpatient Care Centers

Joan Rivers Signs And Discusses Her New Book "Diary Of A Mad Diva"
Comedian Joan Rivers poses before signing copies of her new book "Diary Of A Mad Diva" at Barnes & Noble bookstore at The Grove on July 10, 2014 in Los Angeles, California. Amanda Edwards—WireImage

The comedien apparently went into cardiac arrest while undergoing a procedure at an outpatient center, and had to be transported to a hospital for emergency care

The New York Department of Health is still investigating the death of Joan Rivers, who died Thursday when she did not recover from cardiac arrest. Rivers, 81, was at Yorkville Endoscopy, an outpatient surgical center, for an elective procedure when she ceased breathing and her heart suddenly stopped. An autopsy proved inconclusive, the New York chief medical examiner’s office said Friday.

Rivers’ death is raising questions about how outpatient or ambulatory centers are accredited, and what regulations are in place to ensure patient safety. Each state health department oversees such facilities; some are part of hospitals and therefore regulated by the same organizations that oversee hospitals, while others are independently owned and operated by physicians.

Just under half of states, including New York, require that the latter centers receive accreditation from any of four organizations that set criteria for patient care and safety. The New York Department of Health lists threeAccreditation Association for Ambulatory Health Care, American Association for Accreditation of Ambulatory Surgery Facilities (AAAASF), and the Joint Commission.

As one of the organizations that accredits centers for which Medicare reimburses procedures, the AAAASF has a 162 page checklist of items, from requiring that a circulating nurse is in both the operating room and the recovery rooms, to board certification of surgeons performing the procedures and the presence of crash carts for resuscitating patients should complications occur. Centers also need to have an agreement with a nearby hospital to respond to any emergencies. Because of these criteria, says Dr. Geoffrey Keyes, president of AAAASF, death rates at ambulatory surgery centers that are accredited are similar to those at hospitals.

But if states do not require accreditation or licensure, then centers have to voluntarily apply for the status, which can cost $10,000 over three years and require regular inspections for compliance.

While the majority of ambulatory surgery centers are accredited by one of the four agencies perform the service in the U.S., the bulk of the smaller practices run by one or two physicians who perform surgical procedures at their offices are not. “One of the first questions a consumer should ask a surgeon is what environment do they intend to do the procedure, and whether that environment is accredited, whether it’s a hospital or outpatient center,” says Michael Kulczycki, executive director of the Ambulatory Care Accreditation Program of the Joint Commission.

If the facility is accredited, while it’s no guarantee that complications won’t occur, it’s a reassurance that a high level of patient safety and surgical standards are being met. “My personal belief is that with proactive risk and safety measures in place, and appropriate plans to mitigate emergencies, care in the ambulatory care environment would be as safe as care in an inpatient environment,” says Dr. Daniel Ross, field director for ambulatory programs at the Joint Commission.

TIME medicine

What May Have Caused an American Pilot to Crash

Socata Plane
A Socata TBM-900 (700N) at Glasgow airport in Scotland on March 14, 2014. Iain Marshall

An unresponsive pilot whose plane crashed off Jamaica may have suffered from hypoxia

A New York real estate executive was piloting his his small plane from Rochester to Florida on Friday when he stopped communicating with air traffic controllers before eventually crashing near Jamaica.

Larry Glazer, who frequently flew that route, was traveling with his wife. FAA officials said the private plane had reached an altitude of 25,000 feet, prompting some officials to speculate he may have suffered from something known as hypoxia, in which parts of the brain are deprived of adequate oxygen.

It’s far too early to know for sure. But at that altitude, oxygen is so thin that brain cells can only survive for several minutes before they start dying off. Without enough oxygen, people become inattentive, show poor judgment and eventually stop breathing. With extended exposure at high altitudes, the brain shuts off and slips into a coma. Military pilots dispatched to track the aircraft after it failed to respond to air traffic control signals reported seeing the pilot slumped over.

The FAA has warned non-commercial pilots of the dangers of high altitude changes and hypoxia—in its first phases, the pilot won’t necessarily be aware that he’s experiencing oxygen deprivation. On the FAA site’s training section, a member of the agency’s education team urges more physiology training of pilots so they are aware and prepared for the dangers of hypoxia.

According to an official 1991 FAA report, Civilian Training in High-Altitude Flight Physiology, “Some National Transportation Safety Board staff members have expressed a concern that high-altitude flight physiology training for civilian flight personnel should receive greater emphasis than it currently does.” The report goes on to say, “When pilots combine their private flying skills with their business transportation needs and use their aircraft to meet those needs, it is inevitable that in order to meet a schedule, arrive at a destination, or get home after a meeting, the urge to complete a mission will lead the pilot into a physiologically-unsafe altitude or into conditions for which there has been insufficient training or experience.”

TIME Research

Journal Retracts Paper that Questioned CDC Autism Study

A paper that claimed government scientists covered up data showing a connection between vaccines and autism has been pulled by its publisher

Earlier in August, the journal Translational Neurodegeneration, an open access, peer-reviewed journal, published a re-analysis of a 2004 paper published in Pediatrics that looked at MMR vaccines and autism. The re-analysis of the data, by biochemical engineer Brian Hooker of Simpson University, claimed to find a higher rate of vaccination against MMR among a subset — African-American boys — of the original study population who developed autism than among those who did not, a finding that Hooker claims was suppressed by the authors of the original paper from the Centers of Disease Control. One of the co-authors of the 2004 paper, William Thompson, released a statement admitting to omitting the data after a secretly recorded conversation he had with Hooker was released on YouTube. (Thompson was not available for comment.)

MORE: Whistleblower Claims CDC Covered Up Data Showing Vaccine-Autism Link

Now, however, the editors of Translational Neurodegeneration have retracted Hooker’s paper, noting on its site that “This article has been removed from the public domain because of serious concerns about the validity of its conclusions. The journal and publisher believe that its continued availability may not be in the public interest. Definitive editorial action will be pending further investigation.”

TIME medicine

Whistleblower Claims CDC Covered Up Data Showing Vaccine-Autism Link

The claim, however, may just be more unsubstantiated fuel from the anti-vaccination movement

If you haven’t noticed, there’s a war going on between those who believe in the health benefits of vaccines – that they can prevent deadly infectious diseases such as measles and polio – and those that believe that the immunizations do more harm than good. Now one of the authors of a 2004 government study that found similar vaccination rates among children with and without autism says the study omitted some important data.

The vaccine war is being fought on social media, in social circles and increasingly in doctor’s offices, as physicians are faced with doubts and questions from parents who find themselves being recruited onto the side of skepticism. Skepticism is healthy, and the sign of curious minds, but not when it flies in the face of evidence. Especially gold standard, rigorous scientific evidence that has been accumulating for decades and shows that vaccines are not linked with an increased risk of the developmental disorder.

William Thompson, a senior scientist at the Centers for Disease Control (CDC) and one of the authors of a 2004 study published in the journal Pediatrics, spoke with Brain Hooker, who serves on the board of Focus Autism (which was founded to “put an end to the needless harm of children by vaccination and other environmental factors”), about the data that was not included in the final report. The study looked at both healthy children and those with autism, to see if there were any differences in their rates of being vaccinated against measles, mumps and rubella (MMR), and found none. That suggested that childhood immunizations likely were not contributing to an increased risk of autism. Hooker and Thompson, however, discussed a subset of the 624 children with autism and 1824 without the condition who were studied and Thompson admitted that among African-American boys, the incidence of autism was higher among those who were vaccinated than among those who weren’t. But that information was not part of the paper. Thompson claims he was not aware that the discussion was being recorded, and his statements appeared in a video released on YouTube on August 22 entitled “CDC Whistleblower Revealed.”

Did the CDC cover up the data, as Hooker claims? A couple of things to keep in mind, both about the people behind the video and about how epidemiological studies like the one published in Pediatrics work (and explained in more detail in this article from Science-Based Medicine). For starters, the video was narrated by Andrew Wakefield, the British researcher responsible for seeding the questions about vaccines and autism in the first place. In 2010, the General Medical Council in the UK revoked his license to practice medicine and a year later, the journal that published his paper concluded that his findings were fraudulent.

Next, any time scientists take the original population of participants in a study, however large, and drill down to analyze trends in a subgroup – in this case the African-American boys – the power of the associations they find dwindles. That’s because the numbers get smaller, and in order to be statistically relevant – something known as statistical significance to statisticians – certain threshold numbers and confidence intervals for the connection have to be reached. In the 2004 study, the scientists looked at a smaller set of 355 children with autism and 1020 without for whom they had Georgia state birth certificates, which included additional information that might be relevant for any associations, such as birth weight, gestational age, and mother’s age, race and education. “This information was not available for the children without birth certificates; hence the CDC study did not present data by race on black, white or other race children form the whole study sample. It presented the results on black and white/other race children from the group with birth certificates,” the CDC notes in a statement responding to the video. Thompson claims that the findings were statistically significant, but results from smaller numbers of subjects still don’t hold as much weight as correlations found in the larger group.

In addition, it’s important to note that the study simply correlated age at vaccination and reports of autism, which says nothing about the direction of the connection. For example, the authors of the 2004 study note that “Case children, especially those 3 to 5 years of age, were more likely than control children to have been vaccinated before 36 months of age.” The association between vaccination and symptoms, however, was more likely due to the fact that the children had to be immunized in order to register in preschool, and doesn’t necessarily indicate that the shots contributed to the autism.

In a statement issued through his attorneys, Thompson says “Reasonable scientists can and do differ in their interpretation of information.” He calls for transparency in the data collecting and reporting process, but says that the way that the 2004 study was presented does not negate the importance of vaccination. “I want to be absolutely clear that I believe vaccines have saved and continue to save countless lives. I would never suggest that any parent avoid vaccinating children of any race. Vaccines prevent serious diseases, and the risks associated with their administration are vastly outweighed by their individual and societal benefits.”

TIME Brain

Erasing Bad Memories May Soon Be Possible

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Getty Images (1); Illustration by Mia Tramz for TIME

Using state of the art laser and gas techniques, scientists working with mice make stunning breakthroughs in turning bad memories into better ones

Memories are a complex combination of objective information—the color of a car, the size of a building—and less tangible emotional feelings, like fear, anxiety, joy, or satisfaction. But to scientists, memories are nothing more than a series of chemical and physical changes, the firing of a nerve here, which sends electrochemical impulses to another nerve there, which together encode everything that we associate with a memory.

But exactly what do those changes look like? And is it possible to override them? In a milestone paper published in the journal Nature, scientists may have provided some answers, explaining how emotional baggage gets attached to memories, and how that can be manipulated to quite literally turn bad memories good. In separate work appearing in the journal PLOS ONE, researchers say that a commonly used anesthetic gas, xenon, if administered at exactly the right moment, can also strip the painful and negative feelings associated with a traumatic memory, essentially neutralizing it.

The findings from both groups come from mouse studies, but the two teams are confident that the results will further efforts to understand and find new ways to treat depression and post traumatic stress disorder in people.

In the Nature study, Susumu Tonegawa and his team showed for the first time exactly where in the brain both positive and negative memories are created, and how these emotional layers can be switched around. They exploited a cutting-edge technique they developed called optogenetics to track an emotional memory as it’s made and also manipulated in the brains of mice. They studied both positive experiences—male mice were allowed to spend about an hour with female mice—and negative experiences—the mice were given mild foot shocks.

MORE: 5 Secrets to Improve Learning and Memory

First, the researchers administered a protein, called channelrhodopsin, into mice nerve cells that were activated during and immediately after those experiences (the positive and the negative). The protein reacts to a specific blue wavelength of laser light—and the scientists discovered that when that light was administered to the the part of the mouse’s nerve cells that fired up after those good or bad experiences, the emotion associated with the memory was relived as though it were happening all over again, even absent the stimulus that created it in the first place.

“Optogenetics for the first time allowed us to pin down the cells in the brain that literally carry the information for a specific memory,” says Tonegawa.

The real revelation came when the scientists tested how malleable the connection between the shock and the memory was. They allowed the shocked mice to spend time with females while their brains were hit with the blue light—which triggered their fear of the shock even though they didn’t get one. After 12 minutes of the laser exposure, the mice relaxed. But it wasn’t that they had replaced their fear with more pleasant feelings. Images of their brains showed that new circuits, presumably the ones associated with more positive feelings of being with females, had sprouted between the emotional regions of the brain and the memory center. Likewise, the mice that had had the pleasurable experience with their female counterparts were given the shock while exposed to the blue light, and now showed more fear and anxiety. The original emotional associations were not eliminated and replaced. Instead, says Tonegawa, the positive and negative circuits compete with each other, and whichever is dominant becomes the prevailing emotion linked to a memory.

MORE: This Is the Brain Circuit That Makes You Shy

That could explain how some psychotherapy currently works. To help depressed patients address their feelings, some therapists will revisit negative or emotionally painful experiences. Because memories are not recalled and returned in exactly the same way like a recording, any new information attached to that memory—such as more neutral or positive perspectives about the episode—can help to diffuse its negative impact. Tonegawa’s work in animals suggests that it’s possible to make that psychotherapy technique even more effective if therapists can help patients to focus on more positive feelings while reconsolidating painful memories.

That’s what another group, at McLean Hospital, is hoping to do with a much more simplistic strategy. Edward Meloni, an assistant professor of psychiatry at Harvard Medical School and Marc Kaufman, director of the McLean Hospital Translational Imaging Laboratory, found that the gas xenon, which is used in anesthesia (primarily in Europe), can neutralize the fear associated with a traumatic memory. Exposing mice that had experienced foot shocks to the gas dramatically reduced their fear behaviors – such as freezing up and avoiding areas associated with the painful shock – for up to two weeks. That’s because xenon preferentially targets certain receptors, called NMDA, on brain nerves that are concentrated in learning and memory regions. So when a traumatic memory is activated, those neurons involved in recalling that memory are prime targets for xenon, which blocks the cells from making their usual connections to the emotional hub in the brain known as the amygdala. “My speculation is that xenon lessens the impact of the emotional component, the real emotional pain associated with a traumatic experience,” says Meloni.

MORE: Memories Can Now Be Created — And Erased — in a Lab

It’s not clear yet whether the gas will have similar effects on long-standing traumatic memories such as those involved in PTSD, but Kaufman and Meloni plan to set up a human trial as soon as possible. Ideally, says Meloni, if xenon proves to be effective and safe for reshaping memories, patients who experience debilitating nightmares would be able to give themselves a squirt of xenon just as they would use an asthma inhaler. Since the gas dissipates quickly, so far there doesn’t seem to be a reason to worry about other potentially harmful effects on the brain.

And what about situations that don’t quite reach the level of PTSD, but are traumatic nonetheless, such as the death of a loved one or a bad breakup? “In general I think those painful experiences are probably not going to be impacted by xenon because there really isn’t a specific memory that is reactivated, like a flashbulb moment of trauma,” he says. “It’s more a global heartbreak.”

Because xenon isn’t specific to blocking the negative connections to the brain’s emotional nexus, Kaufman says it’s possible the gas could also be helpful in reducing the highs and the reward sensation associated with addiction. More studies will need to show that xenon could play a role in those situations as well, but both he and Meloni are optimistic. “We’ve got a good start in animals, and as we work through the ladder in getting it to people, I’m hopeful,” says Meloni.

TIME Heart Disease

Eating and Exercise Needs to Be Part of Heart-Health Counseling, Say Docs

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Comstock—Getty Images

A government panel of experts found that behavioral counseling to help people at risk of heart disease to adopt healthier habits can lower their risk of having heart events. But it’s not easy

We know how to lower our risk of heart disease, yet it remains the leading killer of Americans year after year. That’s because the most powerful ways to fend off heart attacks and strokes are also the hardest. Changing our diet and exercise habits involves changing our lifestyles, and doctors have yet to come up with the perfect prescription for that.

But a group of government-convened experts says that one strategy shows promise. They studied the latest trials investigating what works and what doesn’t in getting people to eat healthier and move more, and found that behavioral counseling, either by physicians or nurses or specially trained counselors, can lower risk of heart problems in people who are overweight or obese.

“Intensive behavioral counseling does seem to move the needle,” says Dr. Michael LeFevre, chair of the U. S. Preventive Services Task Force and vice chair of family and community medicine at the University of Missouri Columbia. “We can take people at elevated risk – for starters, people who are overweight or obese and have at least one other risk factor for heart disease — and saw modifications in their risk factors that we think are great enough to have an impact on their health down the road.”

The task force reviewed 74 trials of intensive behavioral counseling – which included education about heart health, nutrition and physical activity, as well as individualized programs in which the participants were provided feedback and problem-solving strategies – and heart outcomes. The counseling was not associated with any harms or serious adverse events, but the sessions did lead to lower cholesterol levels and blood pressure over two years and a decrease rate of diabetes over four years. About a quarter of people were exercising at a moderate to intense level (150 minutes of exercise per week) after several years compared to 10% who were at the start of the studies.

MORE: Prostate-Cancer Screening: Men Should Forgo PSA Testing, Panel Advises

That’s good news, says LeFevre, and prompted the task force to recommend behavioral counseling in a statement published in the Annals of Internal Medicine to help people reduce their risk of heart disease.

The advice is an endorsement of the more formal counseling that more primary care doctors are relying on help their at-risk heart patients. It’s also a definitive statement against the current standard in which doctors merely urge their patients to lose weight or exercise more. “What we didn’t find evidence to support is what most of us do in our practice,” says LeFevre, who is a practicing primary care doctor. “And that is, we just say to John Doe sitting across from us who is overweight, has high blood pressure and smokes, to lose weight. John says, ‘I’m working on that.’ And I say ‘Let me know if I can help – just cut back to eating 1500 calories a day and walk every day.’ We don’t find any evidence that helps.”

What does work, he says, is a program that links both diet and exercise interventions, and that typically helps participants over several sessions occurring over several months, and involves many hours of interaction with a counselor. In those sessions, setting goals and addressing barriers to reaching those goals is an important part of the behavioral counseling – that’s what helps the patients to actually change their behavior rather than simply think about it.

MORE: U.S. Panel Recommends Delaying Regular Mammograms Until Age 50

But as a primary care doctor, LeFevre admits that the counseling isn’t exactly practical or widespread – yet. “One of the major barriers for implementation is that the resources aren’t out there. Many physicians simply don’t have the personnel, programs or location to which to refer people to make this happen.”

That’s the purpose of the USPSTF recommendation—by providing the scientific evidence supporting the benefits and effectiveness of behavioral counseling, LeFevre and the task force members hope that more doctors and hospitals will provide such programs to help their patients—and potentially contribute to lowering heart attacks and heart disease deaths. “We know the risk factors for heart disease pretty well, and we know that behavior change can alter your risk. So the question is, what can the health care community do to support that behavior change? We combed through the literature and looked at all the studies, and this is what seems to work,” he says.

TIME Research

School Should Start Later So Teens Can Sleep, Urge Doctors

The American Academy of Pediatricians (AAP) says there’s strong scientific evidence to support later school start times for middle and high schoolers

When it comes to the importance of sleep, it’s all about the biology, say pediatric experts. And in a report released Monday, the American Academy of Pediatrics supports pushing back start times for older kids, particularly teens, because it’s better for their mental and physical health.

“The evidence is clearly mounting both in terms of understanding the repercussions that chronic sleep loss has on the health, safety and performance of adolescents, and there is also really solid compelling data supporting the fact that delaying school start times is a very important intervention that can mitigate some of the impact of sleep loss,” says Dr. Judith Owens, director of sleep medicine at Children’s National Medical Center and lead author of the report.

In a statement published in the journal Pediatrics, the Academy’s Adolescent Sleep Working Group reviewed the studies to date involving how inadequate sleep among teens—which means anything less than 8.5 hours to nine hours a night on school days—can contribute to health issues such as obesity, diabetes, mood changes and behavior problems. They even analyzed studies linking poor sleep to increased reliance of substances like caffeine, tobacco and alcohol and the effect of sleep deprivation on academic performance. The evidence, they concluded, supports giving teens more time in bed by pushing back the time they have to be at school to at least 8:30am. Even a half-hour delay, some studies showed, can have dramatic effects on improving children’s health and academic performance.

MORE: The Most Well-Rested and Sleep-Deprived Cities in the World

The AAP committee studied the issue of adolescent sleep for nearly four years to come up with this policy statement, says Owens, and that data show that puberty may biologically wire teens to stay up late and wake up late—which means that forcing them to bed earlier won’t do much good. Something about the hormonal changes occurring during that period of development shifts their body clocks, which regulate the balance between sleeping and waking, later, like daylight savings in reverse. Puberty also pressures kids to stay up later because the normal sense of tiredness that builds up during the day is slower to develop among teens, so they can’t fall asleep earlier even if they wanted to. ”It doesn’t change how much sleep they need, but it makes it easier for them to stay awake longer,” says Dr. Mary Carskadon, a professor of psychiatry and human behavior at Brown University Medical School and director of sleep and chronobiology at Bradley Hospital.

That’s why delaying school start times may make more sense than enforcing earlier bedtimes. According to a 2006 National Sleep Foundation poll, 87% of high school students don’t get the recommended 9 to 10 hours of sleep they need to function at their best and promote healthy mental and physical development; most average around seven hours of sleep on weeknights. And the effects of that deprivation may show up in their grades; about 30% of students report falling asleep in class at least once a week, and studies consistently connect less sleep with lower grades in school and on standardized tests. Students who don’t get the recommended amount of sleep also tend to have higher rates of anxiety and mood disorders, including depressive symptoms.

But in the 70 school districts involving more than 1,000 schools that have adopted later start times for high school students, teachers, parents and the students themselves are seeing substantial benefits. In one district that pushed back start times by one hour, half of the students reported getting eight or more hours of sleep, compared to 37% who had prior to the shift.

MORE: Less Sleep Pushes Your Brain to Age Faster

Owens and her colleagues also conducted a study among students at an independent school that delayed start times by 30 minutes. That was enough to shift bed times earlier, by an average of 18 minutes, something that surprised her and her team. They also found that the delay increased the percentage of students getting eight or more hours of sleep a night. “Anecdotally, a lot of the students said they felt better with the extra half hour of sleep they got in the morning, and that motivated them to go to bed earlier as well,” she says. “They said they could focus better and concentrate better and that it took them less time to get their homework finished so they could go to bed earlier.”

None of the studies show that delaying school start times encourages students to go to bed even later, a concern that some parents and health care workers have raised about the policy.

Having high school students start later may also have domino effects on everything from their extra curricular activities, including sports, which often occur after school, and on child care issues for parents who rely on older children to take care of their younger siblings following school. “Communities and school districts really need to go all in and make a commitment [to it],” says Carskadon. “Where it doesn’t work is where schools just dabble and say they will try it for six months to see how it works.” Adds Dr. Cora Breuner, professor of pediatrics and adolescent medicine at Seattle Children’s Hospital at University of Washington and a member of the committee, “we know that implementation of our recommendations wild be challenging but we stand behind these recommendations and strongly ask that they be considered for the health of our children.”

MORE: Poor Sleep Affects Babies’ Weight Later In Life

And in some districts, efforts to overcome the hurdles are starting to work. Some schools, for example, have created after-school programs where younger children can remain at school in a supervised setting until their older siblings or parents can take them home. And in communities in Minnesota and Massachusetts, where elementary school students are starting school earlier to accommodate bus service for the older students later, community volunteers have manned the stops to ensure younger children are safe while they are waiting to be picked up during early morning hours.

“The hope is that this statement will galvanize communities,” says Carskadon. “Now they have another tool in their tool kit, and another set of evidence and advice to take to school committees and school boards, to get communities moving on addressing adolescent sleep.” Given the state of the data on how poor sleep affects adolescent development, adds Owens, “to do nothing Is really to do harm. The status quo of starting schools at 7:15 or 7:20 is not in the best interest of the students.”

TIME Infectious Disease

Polio’s Two Vaccines Are More Effective When They’re Combined

For decades, there’s been a tug-of-war between the oral and inactivated polio vaccines over which is more effective at preventing the paralyzing disease. Researchers have now resolved the dispute and say that pairing them are better than either alone

When it comes to fighting a virus, having as many weapons as possible, especially in the form of vaccines that can prevent infection, is certainly welcome. And that’s always been the case with polio, which has not one but two effective immunizations that can stop the virus from causing debilitating paralysis. Which is more effective in preventing illness and which is better at stopping transmission of the virus? Scientists report in the journal Science that neither is ideal, but that together, the vaccines are powerful enough to achieve both results. The results “revolutionize our thinking about how to use polio vaccines optimally,” says Hamid Jafari, director of polio operations and research at the WHO, who led the research.

Recent efforts to erradicate polio has pitched the two vaccines against each other. Developed in the 1950s and 1960s, one was made by Jonas Salk using killed polio virus, and the other, developed by Albert Sabin, uses a weakened but still live virus that could replicate in the human gut to deliver immunity. Jafari and his colleagues, report that children vaccinated with the oral polio vaccine who then received a boost of the Salk vaccine showed the lowest amount of virus in their feces—one of the primary ways that the virus spreads from person to person—and excreted these viruses for a shorter period of time than children who had been immunized with the oral vaccine and received a boost with an additional dose of the same oral vaccine.

MORE: WHO Declares Health Emergency on Polio

The WHO’s global effort to eradicate polio has relied heavily on the oral vaccine, because it’s a liquid that can be eaily given to children orally, and it’s cheaper. Plus, the oral vaccine, because it contains a weakened virus that can reproduce in the human gut, helped to reduce the volume of virus excreted in the feces, and thus lower the chances that others coming in contact with the feces could get infected.

But in places where polio infections were rampant, such as northern India, the oral vaccines didn’t seem to be doing much good at reducing the burden of disease. Even when children were getting the recommended three doses, rates of infections remained high. “The transmission pressure was extremely high in these areas that were densely populated, had a high birth rate, poor sanitation and high rates of diarrhea,” says Jafari. In those regions, it took an additional 10 to 12 vaccination campaigns—about one a month to provide children with additional doses on top of the recommended three doses—to finally control the disease and limit spread of the virus. It turns out that the immunity provided by the oral vaccine wanes over time.

In order to eradicate the disease, public health officials knew they had to do better. So they tested whether adding in the inactivated vaccine would help. And among 954 infants and children aged five years to 10 years who had already received several doses of oral vaccine, adding a shot of the inactivated vaccine did help them to shed less virus compared to those who received another dose of the oral vaccine.

PHOTOS: Endgame for an Enduring Disease? Pakistan’s Fight Against Polio

With polio currently endemic in Pakistan, Cameroon, Equatorial Guinea, and the Syrian Arab Republic, the WHO declared the spread of polio a public health emergency of international concern, and issued temporary recommendations for all residents and long-term visitors to those countries to receive a dose of either the oral or inactivated vaccine before traveling out of the country. In other countries where polio has been found, such as in some sewage samples and fecal samples from residents in Israel, health officials have also advised residents living in those regions to receive a dose of inactivated polio vaccine in order to limit spread of the virus.

“The inactivated polio virus vaccine is becoming an important tool in preventing international spread of polio,” says Jafari. Whenever outbreaks of the disease occur, health officials are now recommending that even vaccinated individuals who could be infected but not get sick, receive an additional shot of the inactivated vaccine in order to limit the amount of virus they shed and spread to others.

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