A Lifetime of Viruses

Scientists devise an antibody-based test that can generate a person’s complete “viral history” with just one drop of blood.

FLICKR, ALDEN CHADWICK

Last summer, infectious disease specialist Gregory Poland saw a patient at the Mayo Clinic in Rochester, Minnesota, who had a fever, a rash, kidney failure, and—despite seeing several doctors—no diagnosis. Only after talking with the patient for hours and digging into her medical and travel history could Poland generate a potential diagnosis. To test his theory, he had to send a serum sample to researchers at the US Centers for Disease Control and Prevention in Atlanta, who confirmed that his patient had chikungunya.

Situations like this, explained Poland, are not uncommon. “I can’t tell you how many times we don’t know what’s going on,” he said. When tests for all of the usual suspects come back negative, it’s difficult to know what to try next. On top of that, he added, some disease-causing agents are rare. “There are viruses that I know the name of, but I’ve never seen the disease.”

Thanks to a method described today (June 4) in Science, it may be soon be possible to test patients for previous exposures to all human-tropic viruses at once. Virologist Stephen Elledge of Harvard Medical School and the Brigham and Women’s Hospital in Boston and his colleagues have built such a test, called “VirScan,” from a bacteriophage-based display system they developed in 2011. The scientists programmed each phage to expresses a unique viral peptide, collectively producing about 100 peptides from each of the 206 known human-tropic viral species.

The team combined the phage with serum collected from 569 donors in the U.S., Thailand, Peru, and South Africa, allowing antibodies in each sample to bind their target peptides. The researchers then isolated the antibody-peptide-phage complexes, and harvested and sequenced the DNA inside each. The sequences, which can be read millions at a time, represent peptides recognized by the antibodies, revealing which viruses a given donor’s immune system had previously seen.

“This is far beyond anything we’ve had before regarding the human antibody response to viruses,” said Kristine Wylie, a microbiologist at Washington University in St. Louis who was not involved in the work.

Scientists like Wylie have been cataloging viruses living in and on humans for years, typically by searching for viral DNA and RNA sequences in blood and tissues. “Healthy people carry a lot of viruses, asymptomatically,” she said. Knowledge of prior viral exposures can improve health care. For example, it’s good to know whether a patient about to start chemotherapy carries a latent virus that could resurge during treatment.

Detecting a virus by the presence of its genes, however, depends on the virus being present at high enough levels and in easily accessed fluids or tissues. Measuring antibodies produced in response to viruses makes it possible to detect an infection weeks or decades later using only blood serum. But this approach is typically limited to testing for antibodies against one virus at a time. According to Poland, testing for many viruses at once is currently too expensive and requires too much blood to be routinely feasible.

VirScan requires just one drop of blood and, for about $25, screens for antibodies against 206 viruses, covering 1,000 strains. Using the technique, Elledge’s team identified high rates of exposure to common viruses like Epstein–Barr virus (found in 87 percent of adult donors screened) and rhinovirus (found in around 70 percent), many of which Wylie said are consistent with the rates she and others have seen in asymptomatic adults.

Some viruses showed up at lower frequencies than expected. Influenza, for example, appeared to affect only 53 percent of the donors, and chickenpox, just 24 percent. Elledge noted that these apparently low rates may be the result of a potential limitation of the test: the 56 amino acid peptides used for VirScan may have been too short to attract antibodies that only bind longer spans of folded-up peptides called conformational epitopes. Despite this, the team detected antibody responses against 4,406 unique epitopes, most of which had not been recorded in the Immune Epitope Database.

Unexpectedly, each person sampled showed a strong response to just three or fewer peptides per virus, making those peptides immunodominant. Although immunodominant peptides don’t always make the best vaccines, Elledge noted they might still be useful for vaccine design. “You might be able to piggyback on pre-existing immune responses and use that to your advantage,” he said.

Improvements to VirScan—such as the inclusion of conformational epitopes and a reduction in cross-reactivity between viruses with similar proteins—are in the works, said Elledge. Going forward, the team would like to extend its approach to screen for other pathogens, like bacteria, and to use VirScan to look for correlations between viral infections and chronic conditions, such as autoimmune diseases.

Down the line, Poland sees a place for VirScan in the clinic. “They’ve made real progress in what could have been seen as a pipe dream,” he said. “If they can perfect this and move this forward, this changes everything.”

G.J. Xu, et al. “Comprehensive serological profiling of human populations using a synthetic human virome,” Science, 348:1106-1114, 2015.

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Unusual Bird Flu Virus Kills Two Men In China

Two men have died in Shanghai after being infected with the H7N9 bird flu virus strain, one that has never affected humans before, Chinese health authorities reported.

The two patients were aged 87 and 27 years. The Xinhua News Agency reported that the younger man, surnamed Wu, became ill on February 19th, 2013 and died just over three weeks later on March 4th. The older man, surnamed Li, became sick on February 27th and died on March 10th.

The older patients' two sons became ill with flu and were hospitalized. The younger son, aged 55, developed severe pneumonia and died. The older son, aged 67, recovered and is no longer in hospital. Chinese health authorities say that neither son had the H7N9 virus.

A third patient, in Chuzhou in the eastern province of Anhui, also became infected with the H7N9 virus strain and became ill on March 10th. The woman, surnamed Han, aged 35, is reported to be in a critical condition in hospital in Nanjing, capital of Jiangsu Province.

Little is known about how H7N9 spreads among humans

Health experts in China say they do not know how the virus strain has spread. They are certain that the three infected people did not transmit H7N9 to each other. Tests on 88 close contacts of the three infected people found no abnormalities.

The National Health and Family Planning Commission (the Commission) in China says that the three patients started off with coughs and fever, which then developed to pneumonia with breathing difficulties.

Commission laboratories confirmed that all three were infected with H7N9, an avian influenza (bird flu) strain known to affect birds, but not humans.

The World Health Organization (WHO) says there is no vaccine to protect humans from H7N9 infection.

H7N9 does not appear to be highly human transmissible

The Commission emphasized that there is no evidence indicating that H7N9 is highly transmissible from human-to-human. However, it is not possible to draw any conclusions from just three cases.

The Chinese CDC (Center for Disease Control and Prevention) says that it has a team of experts studying the toxicity and human-infection potential of the virus.

Shanghai Daily quotes Jiang Qingwu, dean of Public Health School of Fudan University, as saying "So far, it is still an animal virus not a human virus".

Timothy O'Leary, of the World Health Organization, said in an interview with the Associated Press:

"There is apparently no evidence of human-to-human transmission, and transmission of the virus appears to be inefficient, therefore the risk to public health would appear to be low."

Health departments throughout China have been urged to step up supervision and monitoring of all cases involving flu symptoms, respiratory problems, and pneumonia.

People with fever, coughing, and breathing problems have been told to visit their doctors immediately.

What is bird flu (avian influenza)?

Avian influenza, also known as avian flu or bird flu, is a flu caused by viruses that infect birds and make them sick. It is an infectious disease of birds caused by influenza virus strains type A. Highly pathogenic avian influenza (HPAI) is the more aggressive one.

Avian influenza affects several types of birds, including farmed poultry. In December 2012, pigs in China were found to be infected with the bird flu virus.

Bird flu (avian flu) is the illness, which is caused by the avian influenza virus.

Avian influenza can be transmitted from wild birds to farmed livestock or pet birds, and the other way round. The infection spreads via the saliva, feces, nasal secretions and the feed of infected birds. Since December 2003, there have been many bird flu outbreaks, which have directly killed or caused the culling of millions of farmed poultry and wild birds in Europe, Asia and Africa.

Scientists have identified over 16 different bird flu types. The one that causes the most concern is the H5N1 strain, because it can make humans very ill, and even kill them. Fortunately, H5N1 does not infect humans easily. However, some highly virulent strains have caused severe respiratory diseases in humans.

In the vast majority of human infections, the person was in contact with infected birds or surfaces/objects contaminated with their secretions or feces.

H5N1 kills 60% of humans who become ill after being infected. According to WHO, so far during this millennium H5N1 has killed 359 humans in twelve countries.

Experts worry that an avian influenza virus may one day mutate and become easily human-transmissible.

Scientists reported in the journal mBio last year that a new bird flu virus had infected harbor seals and could pose a threat to human health as well as wildlife

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New Respiratory Coronavirus Claims Second Victim

Another person with a severe acute respiratory infection (SARI) caused by a novel coronavirus 2012 has died, the World Health Organization (WHO) announced on Friday. The second victim, like the first, died in Saudi Arabia.

The announcement follows enhanced surveillance in Saudi Arabia and Qatar that has identified 4 new cases (3 in Saudi Arabia, 1 in Qatar), including the second death, the United Nations health agency reports.

Human coronoviruses are so called because of the crown-like projections on their surfaces. First identified in the 1960s, they are a large family of viruses that cause illnesses in animals and humans.

The illnesses they cause include respiratory infections such as the common cold and SARS (severe acute respiratory syndrome). In 2002, an oubreak of SARS spread from Hong Kong around the world, killing around 800 people.

However, according to information published on the WHO website at the end of September, the new coronavirus is genetically quite distinct from SARS.

The WHO says globally, the total of lab-confirmed cases of novel coronavirus 2012 notified to them is now 6, with 4 of them (including 2 deaths) linked to Saudi Arabia and 2 to Qatar (one reported from the UK and the other from Germany).

Two of the recently confirmed cases in Saudi Arabia are "epidemiologically linked" and from the same family and household. One person died and the other has since recovered, says the WHO.

Two other family members have also been tested: so far one is negative and the result of the other is not yet available.

According to the UK's Health Protection Agency (HPA), the newly reported case from Qatar, was lab-confirmed by them in November. The patient was initially treated in Qatar in October, but then transferred to Germany, and has now been discharged.

The WHO is now reviewing these new developments to see if there is a need to revise the interim case definition it published at the end of September, and any guidance relating to it.

The UN agency says in the meantime:

"Investigations are ongoing in areas of epidemiology, clinical management, and virology, to look into the likely source of infection, the route of exposure, and the possibility of human-to-human transmission of the virus. Close contacts of the recently confirmed cases are being identified and followed up."

The international agency says there is a need for more studies to better understand the virus, and encourages all members of the UN to continue their surveillance of severe acute respiratory infections (SARI).

It is likely the virus is present in more than just two countries, says the WHO, and it suggests patients with unexplained pneumonias should be tested for the new coronavirus, even if they have not been travelling to the two affected countries or are otherwise associated with them.

"In addition, any clusters of SARI or SARI in health care workers should be thoroughly investigated regardless of where in the world they occur," it urges.

More information from the WHO on coronavirus infections.

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Bird Flu Has Now Hit 35 Countries - See The List

In 2003 bird flu (H5N1) was found in Vietnam, South East Asia. It gradually moved its way further into Asia. Over the past few months the geographic spread has taken on a new speed, like a snowball going down a hill gaining momentum. Now (28 February, 2006) 35 countries have been hit by the bird flu virus.

Here is the list

-- Austria
-- Azerbaijan
-- Bulgaria
-- Cambodia
-- China (human cases confirmed)
-- Croatia
-- Cyprus
-- Egypt
-- France
-- Germany
-- Greece
-- Hungary
-- India
-- Indonesia (human cases confirmed)
-- Iran
-- Iraq (human cases confirmed)
-- Italy
-- Japan
-- Kazakhstan
-- Kuwait
-- Laos
-- Malaysia (human cases confirmed)
-- Mongolia
-- Niger
-- Nigeria
-- Romania
-- Russia
-- Slovakia
-- Slovenia
-- South Korea
-- Sweden
-- Thailand (human cases confirmed)
-- Turkey (human cases confirmed)
-- Ukraine
-- Vietnam (human cases confirmed)

Perhaps there are more, maybe there are some dead birds lying around in some other countries that we have not yet found, who knows? It is strange that North Korea, which borders countries that have reported bird flu in their territories (South Korea and China) does not appear on the list.

How many countries bordering Nigeria perhaps already have the virus? So far, only Niger has confirmed the presence of infected birds.

Is there anywhere that is safe from bird flu? According to ornithologists, only Australia and New Zealand stand a chance of staying out of this unpleasant league of bird flu infected countries. Australia and New Zealand do not lie in the paths of bird migration.

(The H5N1 virus itself was first detected in Hong Kong, in 1997)

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Revealed Why H5N1 Is So Deadly For Humans

The H5N1 bird flu strain has killed over half of the 241 humans it has infected since 2003. A team of scientists from the Oxford University Clinical Research Unit may have found out why H5N1 bird flu infection is so much more deadly than normal human influenza viruses. It is all to do with the patient's viral load and the subsequent inflammatory response.

You can read about this study in Nature Medicine.

Before the study the team had noted that H5N1 causes severe disease in humans, but why it is virulent was unclear. In vitro and animal studies had indicated that high viral load is important for disease pathogenesis. They wanted to asses the relevance of these findings for human patients.

The researchers looked at 27 people at the Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam. 18 of them had been infected with H5N1 while the other 9 had been infected with normal human influenza virus subtypes.

They found that those infected with H5N1 had much higher viral loads - concentrations of H5N1 in their blood and pharynx (throat) - than those with normal human flu. They also found that the H5N1 infected patients who had died had much higher viral loads than the H5N1 infected patients who did not die.

Those with a high H5N1 viral load had the highest levels of cytokines. Cytokines control your body's response to infection. The patients who died also had much lower levels of T-lymphocytes.

Put simply, it means that the higher level of H5N1 a patient has, the greater are his/her chances of dying.

High levels of cytokines, low levels of of lymphocytes, and the resulting intense inflammatory responses, probably contributed to more severe lung damage and a greater chance of death, say Dr. Menno and team. They stressed that preventing this intense cytokine response should be the focus of clinical management. This entails early diagnosis and effective antiviral treatment.

This research points to swift and effective use of antivirals, such as Tamiflu or Relenza, in order to prevent virus levels from rising too fast.

Menno D de Jong, Cameron P Simmons, Tran Tan Thanh, Vo Minh Hien, Gavin J D Smith, Tran Nguyen Bich Chau, Dang Minh Hoang, Nguyen Van Vinh Chau, Truong Huu Khanh, Vo Cong Dong, Phan Tu Qui, Bach Van Cam, Do Quang Ha, Yi Guan, J S Malik Peiris, Nguyen Tran Chinh, Tran Tinh Hien & Jeremy Farrar
Nature MedicinePublished online: doi:10.1038/nm1477
Click Here To View Abstract Online

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Two Thirds Of New Mothers Have Trouble Breast Feeding

A survey published in the journal Pediatrics shows that two third of mothers nursing new-borns are unable to manage breast feeding, for as long as they intended.

The World Health Organization (WHO) and the American Academy of Pediatrics take the view that around six months of breast feeding is a target bench mark, meaning only breast milk and medications or micronutrient supplements, but no other liquids or solids. Surveys have shown that few mothers achieve this goal in the US, but it was not specifically known whether this was by accident or design.

Centers for Disease Control and Prevention conducted a survey of pregnant women about their intentions for exclusive breast-feeding and published their results under the title:"Baby-Friendly Hospital Practices and Meeting Exclusive Breastfeeding Intention."

They discovered that although 85% of mothers planned to breast feed for at least three months, less than a third managed to meet their own goal. Those who already had a baby and were married seem to have better chances. Breast feeding within an hour of birth was also seen as an important factor in developing the mother-baby breast feeding regime. On the flip side, those who were obese, were smokers or set themselves longer goals for breast feeding, stood less chance of achieving their target.

In addition, the report shows that when hospitals give out infant formula and or pacifiers, the mothers chances are reduced, presumably because she more easily turns towards the alternatives. The study suggests that increasing "Baby-Friendly Hospital Practices", particularly by supporting mothers to breast feed exclusively while in hospital, will assist more mothers in meeting their goals.

Previous research has shown that babies fed on infant formula from a younger age tend to have more health issues in later life. The research was contested by some, who suggested that babies fed on infant formula immediately or in the first few months after birth, were likely to have many other issues, including unprivileged mothers, working mothers, or those with unhealthy lifestyles. Thus, babies that were not breast fed for as long, if at all, were simply markers for other social issues in their upbringing that might affect their health.

There has been a drive in the UK in recent years to educate and push more mothers to breast feed for longer, however, an article from University of Aberdeen and the University of Stirling, published in the BMJ, was highlighted in March of this year by the Gurdian Newspaper and cause quite an uproar. The Scottish scientists suggested that the six month target from the WHO was overly idealistic, and putting mothers under necessary pressure. Hospital staff were often unavailable to help new mothers and many other practical factors came into play in the months following birth, that they say left the success of hitting the six month goal was largely down to luck.

They state that :

"More achievable incremental goals are recommended. Unanimously, families would prefer the balance to shift away from antenatal theory towards more help immediately after birth and at three to four months, when solids are being considered."

It goes without saying that breastmilk provides babies with essential nutrients and figures are clear that breastfed babies suffer less chance of diarrhoea and vomiting, which can only be good for both mother and baby. The breast fed babies also have fewer chest and ear infections, are less constipated and are less likely to become obese.

The editor-in-chief of BMJ Open, Dr Trish Groves, clarified the article stating: "Any research or other article that seems to be 'anti-breastfeeding' is, rightly, highly controversial. This study is not, however, against breastfeeding: far from it."

The reasons that mothers end up quitting breast feeding seem to come down to a number of factors including:

• Having a difficult start. Mothers are usually tired after giving birth and poor circumstances during the first few days give mothers an understandable reason for giving up. Sore nipples, late nights, and a difficult baby, make it easier to reach for the bottle.
• Baby isn't getting fed enough. It's impossible to tell how much a baby is eating when it's being fed directly from the breast, and this can lead to the worry. Breast fed babies tend to stay at the breast longer, simply because it's relaxing to them, and the human milk is more digestible, so they generally eat more and more often and might appear hungrier. It's easy for a new mother to get nervous and want to start supplementing with a bottle. This of course begins to slow down the breast production and makes continuing breast feeding more difficult.
• Feeling awkward to nurse in public. In our politically correct society, and considering that breasts are considered very sexual, many women just don't feel comfortable exposing themselves in public, and it's hard sit in a rest room or private place for half an hour or more while the baby feeds.
• Needing to go back to work. While some mothers do manage to express milk or nurse their baby while working, the pressures of a modern job don't leave much room for regular feeds. Once the routine is broken, the breasts produce less milk and babies get used to bottle feeding, which quickly leads into using formula when supplies are short.
  
  

At the end of the day, it's important to keep perspective and taking care of a new born can be stressful and tiring at the best of times. Of course setting targets is an admirable goal, and new mother's should be afforded the best opportunities and be educated in the benefits of not looking for the first excuse to use the bottle and formula. None the less a balance needs to be maintained, between offering useful and healthy advice, and simply forcing a demanding socialist regime onto mothers and their newborns.

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Amantadine: Flu / Parkinson's Drug In Treatment For Traumatic Brain Injury

New England Journal of Medicine published an article today showing a significant breakthrough in treating patients with a vegetative and minimally conscious state. The drug, known as Amantadine was previously used to treat flu, but when given to severely injured patients, recovery results were markedly improved.

Neuropsychologist Joseph Giacino of Boston's Spaulding Rehabilitation Hospital, co-leader of the study said :

"This drug moved the needle in terms of speeding patient recovery, and that's not been shown before ... It really does provide hope for a population that is viewed in many places as hopeless."

Doctors have been using Amantadine for some years to treat brain injuries, but there has never been a comprehensive study to analyze the results. The new findings are an important step in the right direction, but many questions remain, including whether the drug will help patients that have less severe injuries, and also whether Amantadine will speed the recovery in the long term.

Doctors have been forced to use a variety of medicines normally approved for other ailments in the hopes that they would help brain injury patients. With nearly two million patients suffering traumatic debilitating injuries, the need for a comprehensive treatment is evident and while three quarters are mild concussions that heal over time, more than 50,000 die each year from brain injuries and another 275,000 are hospitalized.

Study co-leader, John Whyte, M.D., Ph.D, Director of Moss Rehabilitation Research Institute

"Now that we know that amantadine can accelerate neurologic recovery, we need to explore the dose and treatment schedule that provides the greatest and most durable treatment impact ... Importantly, this study adds to the growing evidence that patients with disorders of consciousness have rehabilitation potential that we are just beginning to tap."

The problem to date is that doctors have been treating patients based on hunches and common sense, rather than actual physical data. Amantadine is one such weapon of choice, a flu drug that was approved in the mid-1960s, appeared to improve those with Parkinson's disease, who were treated with it whilst in nursing homes. The drug seems to have an effect on the brain's dopamine system, and the Parkinson's patients showed improved movement and alertness. What started as an intuitive finding, is now approved for Parkinson's.

Whyte continued that:

"(It's now commonly used for brain injuries, and the researchers felt it was important to find out) whether we're treating patients with a useful drug, a harmful drug or a useless drug,"

The recent study was carried out in Germany and looked at 184 disabled patients with an average age of 36. A third of them were in what is termed a vegetative state, where they are mainly unconscious with only short periods showing signs of awareness.

Amandatine was randomly assigned to patients, the rest were given a dummy drug for four weeks. Both groups seemed to show some signs of improvement, but those on amantadine had better, faster results. When researchers stopped the drug, recovery in patients who had received it slowed, and two weeks after stopping treatment, both groups appeared about the same again.

One possible use for the drug is in treating US troops with brain injuries. Since 2000, nearly a quarter of a million US soldiers have suffered traumatic brain injuries, including more than 6,000 serious cases, mostly from bomb blasts or shrapnel. Another area that clearly needs more research is in treating other kinds of trauma, such as that from a stroke.

Giacino said the drug still has value even if it only hastens recovery :

"What condition would we not jump for joy if we could have it
over with faster?"

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Tablets Help Relieve Symptoms Such as Runny Nose, Congestion, Watery Eyes

For many allergy sufferers, getting shots is a pesky, even painful part of ragweed season. Now, researchers report success testing an under-the-tongue tablet as an alternative to injections in people with ragweed allergies.

In a study of more than 500 people with ragweed allergies, people who took the experimental tablets had less nasal congestion, eye tearing, and other allergy symptoms than those who took a placebo. Those given the new pills also needed fewer antihistamines and other allergy medications for relief.

The treatment is a type of immune therapy, the most common form of which is the allergy shot. Tiny amounts of the proteins to which you are allergic are injected to weaken the immune system's response to ragweed, grass, or other allergy triggers.

The new treatment works much the same way, but instead you put a tablet containing tiny extracts of allergens -- in this case ragweed proteins -- under the tongue each day until tolerance develops.

Immune therapy is the only treatment that's been proven to modify the natural course of the allergic disease, "actually turning it off and keeping it suppressed over time," says Johns Hopkins' Peter Creticos, MD, who led the new study.

Shots may work, "but some people are afraid of the needle or don't have time to go to the doctor's office [two to four times a month] during allergy season to get them," he says.

Also, "3% to 6% of people on allergy shots have systemic [throughout the body] allergic reactions that can be severe or life-threatening," Creticos tells WebMD.

That makes the tablets a welcome option, he says.

Merck & Co., which makes the new tablet and funded the study, plans to apply for FDA approval of tablets for both ragweed and grass allergies next year. The grass tablets are already in use in Europe.
The new study was presented here at the annual meeting of the American Academy of Allergy, Asthma, & Immunotherapy.

10 Signs Your Allergies Are Out of Control

Tablets Relieve Ragweed Allergy Symptoms

The new study involved 565 adults with ragweed allergy, some of whom also had asthma. They were given one of two doses of either the once-daily tablet or a placebo for 52 weeks.

During ragweed season, which runs for about four to six weeks in August and September, everyone recorded their symptoms and need for relief medications in electronic diaries.

During the peak two weeks of the season, the tablet reduced symptoms -- including sneezing, runny and itchy noses, congestion, and gritty and watery eyes -- by 17% and 14% at the higher and lower doses, respectively, compared with placebo.

It also reduced the need for standard allergy medications at the two doses vs. placebo.

The most frequent side effects were throat irritation and itching of the mouth. No one died.

Two patients did need epinephrine, an injectable drug used to treat serious allergic reactions. However, one case was due to an unrelated reaction to peanuts.

Some Patients Welcome Alternative to Shots

Asked whether the tablets are as effective as shots, Creticos says a head-to-head comparison of the two is needed to really answer the question.

Mitchell Grayson, MD, an allergy specialist at the Medical College of Wisconsin in Milwaukee, tells WebMD that he welcomes a tablet, as some of his patients find shots annoying or painful. "And the tablets seem to be less likely to cause [life-threatening] reactions than the shots," he says.

One advantage to shots is that many different allergies can be treated at once, Grayson says.

"Most Americans are allergic to many different things, and with injections, you can pretty much cover all of them. So far, the tablets are each directed at different allergies -- one for grass, one for ragweed, for example. That wouldn’t be very convenient for a person with [a lot of] allergies," he says.

Allergy shots typically are taken for about two to five years, after which many people can stop them and feel relief for years afterward, according to Grayson. It's not yet known for how long people will have to take the new tablets.

If approved, the tablets would only have to be taken for four months before, and during the four to six weeks of, ragweed season, Creticos says. They were given for 52 weeks in the study so the researchers could better assess their safety.

About 60 million Americans suffer from seasonal allergies, also referred to as hay fever and allergic rhinitis.
These findings were presented at a medical conference. They should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.

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