Booster Shots

Oddities, musings and news from the health world

Category: flu

Rodent of the Week: closing in on a universal flu vaccine

July 2, 2010 |  1:00 pm

Rodent_of_the_week universal influenza vaccine Flu viruses mutate rapidly, meaning that vaccines against the flu have to be continually updated to target the latest strains. Moreover, antiviral medications to combat flu sometimes become ineffective because of viral mutations. Thus, finding a so-called universal flu vaccine that could be used against a wide range of viruses over a longer period of time has been a long-held dream of medical experts and the subject of a lot of research.

Scientists reported this week that they have taken another step toward a possible universal flu vaccine. They discovered a target on the influenza A virus that has not changed much -- unlike other regions of the virus -- called influenza matrix 2 protein (M2e). The researchers then found rare, naturally occurring antibodies in humans that target the protein. When these antibodies were given to mice infected with influenza, 60% to 80% recovered compared to a 10% survival rate in the untreated mice. The antibodies protected against two influenza strains: seasonal human H1N1 and an avian flu, H5N1.

The study was completed by researchers at the University of Wisconsin-Madison, University of Tokyo, Johns Hopkins University and Theraclone Sciences of Seattle. It was published Monday in the Proceedings of the National Academy of Sciences.

While humans can produce these antibodies against the M2 protein as part of the immune system's natural response, levels appear to be too low to trigger enough protection. However therapeutic levels of antibodies might create the necessary protection.

-- Shari Roan

Photo credit: Advanced Cell Technology Inc.

First-ever flu vaccine for Fido approved

June 15, 2010 |  4:20 pm

Dog It may surprise you to learn that since 2004, man's best friend has had to endure the misery of influenza just as we have, since a strain of influenza known as H3N8 apparently jumped from horses to dogs and developed the ability to spread readily from hound to hound.

And if dogs worried the way humans did, they'd be worried about H3N8 for the same reasons we all worried about the H1N1 virus that suddenly appeared last year: Since dogs have developed no immunity to this new canine influenza virus, they're prone to catching it very readily if exposed. And because dogs, like their human companions, lead busy, active lives -- going to doggie daycare, putting up in boarding kennels, attending dog shows and meeting friends at dog parks -- they're at risk of developing the symptoms we recognize so well: sneezing, coughing, fever, lethargy, loss of appetite and even pneumonia.

The U.S. Department of Agriculture has noted outbreaks of doggie influenza in 33 states.

What comes next should be no surprise: The USDA, which oversees biological medicines administered to animals, has just licensed Nobivac, a first-ever vaccine to protect Fido against canine influenza. Generally, any dog that is in close contact indoors for more than six hours with another dog is considered at risk, and a dog's human companion should consider asking the veterinarian about the shot, produced by Intervet/Schering Plough Animal Health.

Nobivac has been in limited use under a conditional license for a year, while further safety trials have been conducted, according to Dr. Lisa Saabye, a veterinarian and technical service manager for Intervet. Saabye said those trials have shown the vaccine to be "overall very safe," with no adverse reactions observed in 746 dogs vaccinated. The vaccine is to be given as an initial injection, then a booster between two and four weeks later, and after that, yearly.

Canine flu does not circulate during a predictable season, as do most strains of influenza that affect humans. But Saabye said that summer seems to bring an uptick in outbreaks because dogs tend to spend more time together with other dogs in kennels while their human companions vacation.

Wonder if your dog's feeling poorly? Check out symptoms here.

-- Melissa Healy 

Become a fan of our Facebook page and get a steady stream of health-and medical-related news, musings and the occasional oddity.

Photo credit: Kieran Doherty / Reuters

Swine flu pandemic not over yet, the WHO says

June 3, 2010 |  8:22 am

Pig Confounding expectations, an emergency committee of the World Health Organization unanimously recommended Thursday that the H1N1 influenza pandemic remain at the highest level of the agency's alert scale, Phase 6. The committee will confer again in July to reassess its recommendation when data from the winter influenza season in the Southern Hemisphere become available.

"We're still in the pandemic," WHO spokesman Gregory Hartl said.

Because of sharp declines in swine flu activity around the world, many observers had expected the 15-member committee of experts, whose members are anonymous, to declare that the pandemic was in its "post-peak" phase, or even in its "post-pandemic" phase, which would mean that the pandemic was over.

But a statement from WHO Director-General Margaret Chan noted that, while "the period of most intense pandemic appears likely to have passed for many parts of the world," activity is continuing in some areas and many people remain vulnerable. The virus is most active in parts of Southeast Asia and the Caribbean, but experts fear a further outbreak.

Many critics have charged the agency with overreacting to the emergence of the virus, particularly because symptoms have generally been mild, but experts continue to warn that a small mutation in the virus could cause it to spread more rapidly or to become more lethal. To date, 18,000 deaths from laboratory-confirmed infections have occurred, but most experts think the true number is several times higher.

-- Thomas H. Maugh II

The CDC says seasonal flu vaccinations rose this past winter

April 30, 2010 | 12:37 pm

The publicity surrounding the pandemic H1N1 influenza virus apparently had a good side effect, the Centers for Disease Control and Prevention reported Thursday. Seasonal flu vaccinations reached 40% of the eligible population this past winter, up from 33% the previous winter, the agency reported in its Morbidity and Mortality Weekly Report. The biggest increase was observed among children age 17 and younger, with 40% of that group being vaccinated, compared with 24% in the previous season.

Altogether, 114 million to 115 million doses of seasonal flu vaccine were distributed. Considering wastage and the need to give two shots to children younger than 10, the agency estimates that more than 100 million Americans were vaccinated this past winter.

The group least likely to be vaccinated was healthy adults ages 18 to 49: Only 28% were vaccinated, compared with 22% last year.

Among children, Nevada had the lowest percentage vaccinated, 23.6%, while Hawaii was the highest at 67.2%. Among adults, Nevada was again the lowest with 32.4% vaccinated, while Minnesota was highest with 52.5%.

California ranked a little below the national averages:

-- Everyone older than 6 months: California 36.4%, nationally 39.7%

-- Children ages 6 months to 17 years: California 33.7%, nationally 40.0%

-- Adults ages 18 to 49 with underlying chronic conditions: California 26.7%, nationally 36.2%

-- Healthy adults ages 18 to 49: California 25.2%, nationally 27.6%

-- Adults ages 50 to 64: California 52.6%, nationally 45%

-- Adults 65 and older: California, 63.3%, nationally 68.0%

Among all the groups eligible for vaccination, whites were highest with 42.5% vaccinated, Latinos were second with 33.6% and blacks were lowest with 32.2%. The same rankings occurred among children.

The results were obtained from two separate telephone surveys conducted between October 2009 and February of this year. Most respondents seemed to know the difference between the seasonal flu vaccine and the swine flu vaccine, they said.

-- Thomas H. Maugh II

The CDC sees a very small risk of complications with swine flu vaccine, but is it real?

April 26, 2010 | 12:53 pm

Pig Researchers at the Centers for Disease Control and Prevention have observed a very small risk of complications associated with the vaccine for pandemic H1N1 influenza, but the potential increase in risk is so small that they are not sure if it is real or simply an artifact of the increased monitoring for complications that has accompanied the swine flu vaccination program.

A CDC risk assessment working group reported to the agency's National Vaccine Advisory Committee on Friday that they had observed a very small increase in the risk of Guillain-Barre syndrome, Bell's palsy and thrombocytopenia in some monitoring programs, but not in others. "Because the effects are so small, it is hard to say whether it is due to chance or a real effect," said Dr. Stephen Redd, director of the CDC's influenza coordination unit.

"In terms of public health, we are definitely not concerned," added CDC spokesman Tom Skinner. "When you have as robust a system as we have to look at safety issues, these things are going to pop up. But we have no indication whatsoever that this vaccine isn't safe and effective."

Guillain-Barre syndrome, which causes damage to nerves in the arms and legs and normally strikes one or two people per 100,000, was associated with vaccination for the 1976 swine flu outbreak, and many vaccine critics have been particularly concerned that it could be a side effect of the new swine flu vaccine. The advisory committee concluded that the maximum number of cases associated with the current vaccination campaign is less than one per 1 million vaccinations in the worst case scenario and that there is no actual increase in risk.

Bell's palsy is an inflammatory condition, usually caused by viruses, that leads to a weakening of nerves in the face and body on one side. Some surveillance systems have identified a small increased risk for the disorder and others have not, Redd said. If there is a risk, the magnitude is small, he added. Researchers are studying the problem further to calculate the actual risk. One thing that needs to be done, he added, is to ensure that those diagnosed with Bell's palsy actually had it.

Thrombocytopenia, a low level of platelets in the blood, can be caused by a number of things, including drugs. Like Bell's palsy, Redd said, the risk appears to be very low and researchers need to confirm that those identified with the disorder actually had it.  With either Bell's or thrombocytopenia, most people generally recover on their own.

The working group "did not recommend any immediate response" to the findings, Redd said, but will continue studying the situation and report back to the vaccines committee every two weeks.

-- Thomas H. Maugh II

You don't need modern transportation to fuel a flu pandemic

April 26, 2010 | 12:01 pm

Flu The H1N1 “swine flu” emerged in California and Mexico just about a year ago and made its way around the globe in about two months. Would it have spread more slowly without the benefit of planes, trains and automobiles?

Perhaps, but not by much. That’s the conclusion of a new study examining the spread of the 1889 Russian flu.

Back in 1889, Russia and 18 large European countries were connected by more than 125,000 miles of railroad (more than are in place today). A transatlantic journey by boat lasted less than six days – not quite as quick as it is now (though perhaps comparable to the recent experience of airline passengers stranded in Europe by Iceland’s Eyjafjallajokull volcano).

So, how long did it take for the virus to circumnavigate the globe? Less than four months, according to a report by French researchers published online Monday in Proceedings of the National Academy of Sciences.

The researchers examined public health records in 96 European and American cities, along with data from the French, British, Swiss and German armies. After St. Petersburg hit peak mortality in late November of 1889, it took three weeks for peak mortality to hit Germany, two more to reach Paris, and one week beyond that to make it all the way to the United States. On average, the virus spread through Europe at a rate of 245 miles per week. In the U.S., it traveled at the rate of 631 miles per week.

The Russian flu itself was not terribly deadly – between 0.1% and 0.28% of people sickened with the virus died from it. That puts it squarely in the range of the 1957 Asian flu and the 1968 Hong Kong flu. (By comparison, the fatality rate of the 1918 Spanish flu was about 10 times higher.)

Mathematical models suggested that speedy international air travel was not a crucial factor in the spread of the swine flu and that grounding flights would have been pointless. The French researchers say their results bolster that theory.

-- Karen Kaplan

Photo: This map plots the Russian flu's spread across Europe week by week. Credit: A.J. Valleron / National Institute of Health and Medical Research, Paris

The CDC releases new estimates of swine flu infections

April 21, 2010 | 12:04 pm

Pig As of the middle of March, at least 60 million Americans had been infected with the pandemic H1N1 influenza virus, about 270,000 had been hospitalized and about 12,270 had died, according to the latest estimates from the Centers for Disease Control and Prevention released Tuesday. The new estimates represent an increase of about 1 million infections, 5,000 hospitalizations and 270 fatalities since the last estimates a month ago. The small increase reflects the CDC's recent reports indicating that swine flu activity has lessened in most areas of the country.

The virus has struck primarily in younger people. The CDC estimates that 19 million infections occurred in children 17 and younger -- about a quarter of this population. There were 86,000 hospitalizations and 1,270 deaths in this group. Among young adults ages 18 through 64, there were 35 million infections, 158,000 hospitalizations and 9,420 deaths. The infection total amounts to about 18.5% of this age group.

In normal seasonal flu, the elderly are the most seriously affected, but that has not been the case with swine flu. The number of cases among those over 65 was 6 million. That represents 15.8% of the population, up from 13% a month earlier. There were 26,000 hospitalizations and 1,580 deaths.

Overall, swine flu activity in the U.S. remains low. New data from the American College Health Assn. released Wednesday indicates that cases of influenza-like illnesses on college campuses remained very low in the week ending April 16, about 1.1 cases per 10,000 students. The incidence has remained below 5 cases per 10,000 students for more than four months, the organization said, and there is no evidence of a third wave of infection.

-- Thomas H. Maugh II

H1N1 flu death rates higher among pregnant women

April 21, 2010 |  6:00 am

Romo20 Pregnant women who were infected with H1N1 influenza last year had a much higher risk of dying from complications of the illness compared with other groups, government researchers reported Tuesday.

Data from the Centers for Disease Control and Prevention show that, during the five-month peak of the outbreak from April through August, 5% of H1N1 deaths were among pregnant women although they account for only 1% of the population.

The study, published in the Journal of the American Medical Assn., supports previous research that found H1N1 is particularly dangerous during the third trimester of pregnancy. Taken together, the research leaves no doubt about the value of H1N1 flu vaccination for all pregnant women and rapid treatment with antiviral medications (TamiFlu) as soon as flu symptoms become apparent.

The dozens of young women who died in 2009 left behind grieving families who can scarcely believe how a healthy wife and mother could be taken so swiftly. A story on one such family, who live in Santa Ana, was published earlier this year in the Los Angeles Times.

-- Shari Roan

Photo: A memorial to a Santa Ana woman who developed H1N1 flu while pregnant and later died. Photo credit: Don Barletti  /  Los Angeles Times

Influenza's peaks take an easterly route across the U.S.

April 16, 2010 |  3:22 pm

Flushot The flu may move its victims -- to stay in bed, to resolve to get a flu shot next year, to curse the (probably young and sniffly) family member who gave it to them  -- but it also moves, in a way, itself. From west to east, to be exact.

Researchers have known that flu season traditionally occurs in winter, and from year to year they've had a pretty good idea of which strains will be dominant. But predicting the path of illness has been difficult. So researchers at Tufts University attempted to establish a pattern for flu outbreaks' timing and intensity.

They analyzed older adults' hospitalization records for the 1991 through 2004 flu seasons. (This means the new H1N1 strain was not part of the equation.) And they found that flu seasons typically peaked first in the Western states and later in Eastern states. Nevada, Utah and California led the way; Rhode Island, New Hampshire and Maine wrapped things up.

So, you may ask? It's all about prevention, the researchers say.

Or as they put it: "Understanding the geographical patterns of influenza spread and utilizing multiple parameters for predictive modeling are essential for guiding prevention efforts."

Here's the full study of flu movement, published Thursday in PLoS One. (Don't forget to check out the map.)

-- Tami Dennis

Photo: This year's seasonal flu shot will target the new H1N1 strain and two other strains.

Credit: Bloomberg

Swine flu vaccination rates vary widely around the country

April 1, 2010 | 12:04 pm

Pig Vaccination rates for the pandemic H1N1 influenza virus have varied widely around the country, with New England having the highest vaccination rates and the South having the lowest, the Centers for Disease Control and Prevention reported Thursday in the Morbidity and Mortality Weekly Report.

Rhode Island had the highest overall rate of vaccination for the swine flu, with about 39% of its population immunized, while Mississippi had the lowest rate, with only 13% receiving the shot. Georgia had the lowest rate of vaccination among children, with only 21% of them receiving the shots. Perhaps coincidentally, Georgia is now the state with the highest level of ongoing swine flu activity.  "It's possible that [the outbreak there] is related to vaccine coverage," Dr. Anne Schuchat, director of the CDC's National Center for Immunization and Respiratory Diseases said Thursday in a telephone news conference. "It's possible there are more people susceptible to the virus there. It's also possible that they are a herald of what could happen in other states."  Georgia and other Southern states were the ones first affected in last fall's second wave of swine flu.

California was in the middle of the pack, with 31.2% of children under age 18 vaccinated, 27.7% of young adults in the targeted high-risk groups and 13.9% of those aged 25 to 64 who were not in the targeted groups.

The survey results, which covered the period through the middle of February, indicate that 72 million to 81 million Americans were vaccinated against swine flu and 81 million to 91 million doses were administered. Children under the age of 10 require two doses. Overall, about one in four people were vaccinated, but there was a wide variation in percentages, with three times as many people vaccinated in the most successful states as in the least successful. "We had a great success with children and a greater success with the target population than the population in general," Schuchat said. "Overall, the country did an extraordinary job in responding."

The vaccination effort among healthcare workers was less successful, however. About 62% of them received seasonal flu vaccinations -- the highest rate in recent years -- but only 37% of them got a swine flu shot. The highest vaccination rates were observed among those who worked in intensive care units, in burn units and with obstetric patients. If employers recommended or required vaccination, employees were much more likely to get them. "The healthcare environment is one where infections can spread," Schuchat said, and officials are happy that seasonal flu vaccination rates are rising, but disappointed that the same is not true for swine flu.

So far, the government has shipped 126 million doses of swine flu vaccine and another 36.5 million finished doses are in storage. The government also has bulk antigen in storage, but that has a much longer shelf life and could potentially be used in next season's seasonal flu vaccine. Schuchat conceded that many doses of the vaccine probably will have to be discarded, but "we made a conscious decision to have more than enough doses of vaccine rather than less than enough."

-- Thomas H. Maugh II


The Latest | news as it happens

Recent Posts
test |  March 15, 2011, 4:00 pm »
Booster Shots has moved |  July 12, 2010, 6:02 pm »