from the TIMES OF LONDON
Flu vaccines 'not worth the trouble'
FLU vaccines may be far less effective at combating seasonal outbreaks than previously thought, researchers say, adding that they may not be worth the cost and effort required to produce them.
According to a review published today, there is little clinical evidence that the vaccines reduce deaths significantly, hospital stays and time off work among those most at risk from seasonal flu, including the over-65s and those with chronic heart and lung conditions.
Public policy worldwide recommends the use of inactivated influenza vaccines — those that contain dead viruses and are given with a needle in the arm — to prevent outbreaks. More than 15 million doses of vaccine have been ordered for use this winter in Britain.
But according to Tom Jefferson, a vaccines expert, vaccines given to children under 2 have the same effect as if they were given a dummy drug. He is calling for an urgent re-evaluation of vaccination campaigns.
Writing in the British Medical Journal, he says that because influenza viruses mutate and vary from year to year, it is difficult for scientists to study the precise effects of vaccines and that most existing studies are of poor quality.
Responding to Dr Jefferson’s comments, David Salisbury, director of immunisation at the Department of Health, said: “In older people, protection against infection may be less, but there is good evidence showing that immunisation reduces broncho- pneumonia, hospital admissions and mortality.”
TAMIFLU RESISTANC AND AVIAN FLU
By Steven Reinberg
HealthDay ReporterWed Dec 21,11:48 PM ET
WEDNESDAY, Dec. 21 (HealthDay News) -- One of the few drugs known to be effective against the potentially pandemic avian flu is the antiviral drug Tamiflu, but a new report finds further evidence that some patients may develop resistance to it.
A report issued last October outlined one such case in Vietnam. Now, a new article gives more details on two Vietnamese patients who were resistant to Tamiflu (oseltamivir) and died from the H5N1 avian flu virus despite treatment with the drug.
According to the report, six surviving patients who were also treated with the drug appeared to respond well to the therapy, which was associated with a rapid decline of viral load to undetectable levels in the blood.
The report appears in the Dec. 22 issue of The New England Journal of Medicine.
A research team from the Oxford University Clinical Research Unit and Hospital for Tropical Diseases, in Ho Chi Minh City, believes the failed cases show that in some H5N1-infected patients, the recommended dose of Tamiflu is unable to stop the virus from replicating.
In these cases, not only does the virus spread, but a viral resistance to Tamiflu may develop.
The study's lead author, Dr. Menno D. de Jong, said the resistance is unsurprising, but added, "this does not automatically extrapolate to the situation in the event of an influenza pandemic."
"While our study shows that the drug seems to be effective in suppressing viral replication in at least some patients, it also clearly shows that oseltamivir resistance in H5N1 can develop, and if this happens it may render the drug not effective," de Jong said.
"The availability of alternative antiviral drugs, which remain active against oseltamivir-resistant virus, is important," de Jong said. "One such drug is zanamivir. In addition, strategies to prevent or delay resistance development, for example, higher dosing or combination therapy needs to be explored."
"My advice to patients is to remain calm," de Jong added. "High resistance rates have been observed in human flu as well, generally without detrimental clinical effects."
The reasons for Tamiflu's ineffectiveness in some patients is unclear, however. The researchers speculated that the virus may be replicating too fast for the drug to stop it, or somehow the drug becomes altered in these patients.
One expert believes, however, that Tamiflu resistance may not be the reason the two patients died. Instead, their deaths could be due to the virulence of the particular virus.
"There is no telling that the development of resistance has anything to do with the fatal outcome of these patients," said Dr. Arnold S. Monto, a professor of epidemiology at the University of Michigan School of Public Health, Ann Arbor. "We do not suspect that with this virus that we are going to get 100 percent cure."
Monto noted that the H5N1 virus may not be able to spread easily, since it seems to take a very large amount of the virus to move from birds and then infect people. "This virus is somewhat lacking in fitness -- its ability to infect and transmit [to people]," he said. "On a population basis, this virus might not take off."
According to Monto, a new report about to be issued shows that Japan, where Tamiflu is widely used, has not seen an emergence of a resistant flu virus. "Appropriate use of Tamiflu in treating seasonal influenza should not be inhibited because you are worried that you may be enhancing the emergence of a resistant virus," he said.
Despite this, Monto believes that other antiviral drugs to treat the flu are needed. "It's an unhealthy situation to have the whole world dependent on one drug for treating a very important infection," he said. "We can't ensure that this resistance will not emerge. We need to be sure that we have a backup if it does."
Faced with the growing fear of a pandemic of deadly avian flu, the number of requests by patients for prescriptions for Tamiflu has increased dramatically. In increasing numbers, patients have been asking their doctors for Tamiflu so they can be sure they have a supply should an outbreak occur.
One expert, writing in the same journal issue, cautions doctors not to let patients stockpile Tamiflu as a way of being prepared for an outbreak of avian flu.
Physicians are receiving requests by patients to give them prescriptions for Tamiflu, and in many cases, doctors are acceding to these requests, because it's easier than arguing with patients, said Dr. Allan S. Brett, a professor of medicine at the University of South Carolina School of Medicine, Columbia.
"Physicians should not yield to requests for Tamiflu, when the purpose is personal stockpiling," Brett said. "The patient is asking it for some hypothetical event in the future that may or may not even come," he said.
Brett also cautioned that allowing patients to have the drug may encourage them to take it when they think they have the flu, but only have a bad cold. "People may say, 'This could be influenza, so I'll just start taking the drug,' and then it becomes a real waste," he said. "In addition, widespread unnecessary use will increase the chance of resistant virus."
Another expert, writing in the journal, agreed with Brett.
"I focus on the issue of the development of resistance in influenza to Tamiflu," said Dr. Anne Moscona, a professor in the departments of pediatrics and microbiology and immunology at the Weill Medical College of Cornell University in New York City. "This means that the influenza may develop to [a point] where it is no longer able to be killed, to be treated by Tamiflu."
Moscona isn't surprised that resistance to Tamiflu is developing in the H5N1 virus. "We expected resistance to develop," she said. "Resistance is developing in seasonal flu and now resistance is developing in avian flu."
"There is no pandemic flu right now," Moscona said. "Really, Tamiflu remains an effective and important drug in seasonal influenza. Physicians should not be prescribing Tamiflu to people who just want to stockpile it. We should use these drugs to treat people who are sick."
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Flu Shots May Not Save Lives -- Study
CHICAGO (Reuters) - The flu vaccinations that doctors hoped would save the lives of fragile elderly people have apparently failed to lower death rates, U.S. researchers said on Monday.
More people whose health could be put at risk by influenza have heeded the call to get vaccinated before flu season, but the death rate during the winter flu season remained the same rather than declining, they said.
Based on U.S. mortality rates from 1968 to 2001, the study by the National Institute of Allergy and Infectious Diseases (news - web sites) found no correlation between increasing vaccination rates after 1980 and declining death rates in any age group.
"We conclude, therefore, that there are not enough influenza-related deaths to support the conclusion that vaccination can reduce total winter mortality among the U.S. elderly population by as much as half," study author Lone Simonsen wrote in The Archives of Internal Medicine (news - web sites).
Previous studies have estimated that vaccine programs have cut mortality rates among the elderly by about half.
While the vaccination rate in 2001 rose to 65 percent among elderly Americans from around 20 percent before 1980, the rate of excess winter deaths has remained flat instead of declining by an expected 40 percent.
Because deaths spiked in some years when a virulent form of flu was epidemic, the findings may not be conclusive, the researchers said.
The report suggested earlier observational studies may have had skewed data. For one thing, influenza sufferers may have died from secondary complications brought on by flu after their symptoms had passed, it said. In addition, vaccines often fail to activate antibodies in the elderly.
Further evidence may come after this flu season since an initial U.S. shortage of flu vaccine should have an effect on mortality rates, one way or the other, the report said.
"Either way, this vast disconnect between conclusions from different studies must be sorted out," it said.
JAMA Patient Page:
Do You Have The Flu?
The common cold and influenza (commonly called flu) are both respiratory infections caused by viruses. But the flu is considered more serious because of more severe symptoms that can lead to pneumonia and even death in persons who have other chronic diseases.
With both the cold and flu, you may experience a stuffy nose, sore throat, and sneezing. Tiredness, fever, chills, headache, and major aches and pains may mean you have the flu. Neither the common cold nor flu need to be treated with antibiotics. Consult your doctor if your symptoms get worse or persist for more than a few days.
One of the best ways to prevent flu infection is to get a flu vaccine from your doctor. A study in the March 10, 1999, issue of The Journal of the American Medical Association shows that the vaccine is 88 percent effective in preventing influenza type A infection and 89 percent effective in preventing influenza type B infection. A second study in the same issue shows that it may be especially advisable for certain groups of people, such as women younger than age 65 with certain chronic medical conditions, to get an annual flu vaccine.
Who Should Get a Flu Shot?
- All people aged 65 years or older
- People of any age with chronic diseases of the heart, lung or kidneys, diabetes, compromised immune systems, severe forms of anemia, or asthma
- Residents of nursing homes and other facilities where patients with chronic medical conditions live
- Children or teenagers who are receiving long-term aspirin therapy and who therefore may be at risk for developing Reye syndrome (a neurologic disorder characterized by brain or liver damage) after a flu infection
- Women who will be in the second or third trimester of pregnancy during the flu season
- Health care professionals and volunteers who work with high-risk patients
- People who live in a household with a person who fits into any of the categories above
LEADING CAUSES OF DEATH, UNITED STATES, 1995:
1 Heart disease 737,563
2 Cancer 538,455
3 Cerebrovascular disease 157,991
4 Chronic obstructive lung disease 102,899
5 Unintentional injury 93,320
6 Pneumonia and influenza 82,923
7 Diabetes 59,254
8 HIV and AIDS 43,115
9 Suicide 31,284
10 Chronic liver diseases 25,222
Sources: National Foundation for Infectious Diseases, 1996-97, and Injury Chartbook, Hyattsville, Maryland, 1997
What to Expect:
The flu shot contains no live virus, so you cannot get the flu from the shot. In the United States, flu season usually occurs from about November to April, and the best time to get the vaccine is between September and mid-November. Flu viruses continually change, so it is important that you receive the flu vaccine every year. Most people do not experience side effects from the flu vaccine; however, some people may feel sore at the vaccination site, and other minor, uncommon side effects include headache or low-grade fever for about a day after vaccination.
What is Influenza?
Influenza is a highly contagious respiratory infection. It is spread person-to-person through infectious droplets, such as when an infected person coughs or sneezes. It causes symptoms that include headache, chills, and dry cough, followed by body aches, fever, nasal congestion and sore throat. Symptoms usually appear within two days to four days days of being infected, and a person is considered contagious for another three days to four days after symptoms appear. There are three types of influenza viruses (types A, B and C), with type A being the most prevalent and associated with the most serious epidemics.
Flu Shot Works Best in Well-Rested Individuals
Tue Sep 24, 5:38 PM ET
By Charnicia E. Huggins
NEW YORK (Reuters Health) - An annual vaccination may be the best way to protect against the influenza bug, but to guarantee its effectiveness, people should also be sure to get a good night's sleep before they get their flu shot, new study findings show.
"Getting your flu shot after not having enough sleep may not offer the same protection as getting it when well-rested," study author Dr. Eve Van Cauter of the University of Chicago in Illinois told Reuters Health.
"Chronic partial sleep loss, as experienced by millions of Americans today, has an adverse effect on immune function," she added.
To investigate, Van Cauter and her team studied 25 healthy young men. Eleven had their sleep restricted to just 4 hours a night on 6 nights of the week, followed by 12 hours of sleep per night for a full week. They were vaccinated against the flu on the morning of the fifth day during their sleep-deprived week. The remaining 14 men maintained their usual bedtimes before they were vaccinated.
At follow-up, 10 days after the vaccinations, the investigators found that the men who were immunized while sleep-deprived had an immune response to the flu that was less than half of that shown by their better-rested peers.
At both the 3- and 4-week follow-ups, however, there were no great differences in immune response between the two groups, the researchers note. Their findings are published in a letter to the editor in the September 25th issue of The Journal of the American Medical Association ( news - web sites).
"These findings add to a growing body of evidence indicating that sleep curtailment has adverse health effects," such as making people more prone to colds and other illnesses, Van Cauter said.
The study was partially funded by grants from the National Institutes of Health ( news - web sites).
SOURCE: The Journal of the American Medical Association 2002;288:1471-1472.
Influenza Vaccine Recommendations
The most important control measure for the prevention of influenza outbreaks in any population is annual vaccination with the influenza vaccine. The Advisory Committee on Immunization Practices (ACIP) has prioritized target groups for influenza vaccination.[1] People who are included in the highest priority group are those most at risk for complications of influenza (see Table 1). This group includes: (1) persons aged 65 years or older; (2) residents of nursing homes and other facilities where people with chronic illnesses reside; (3) adults and children who have chronic disorders, especially pulmonary or cardiovascular illness, chronic metabolic diseases (eg, diabetes), renal dysfunction, hemoglobinopathies, or immunosuppression such as HIV; (4) children and teenagers who receive long-term aspirin therapy and are therefore at risk for Reye syndrome following an influenza infection; and (5) women who will be in their second or third trimester of pregnancy during the influenza season.
People who are between the ages of 50 and 64 years are also included in the ACIP's recommendation for vaccination, because this age group has a high prevalence of chronic medical conditions. People who have close contact with at-risk individuals (eg, healthcare workers, family caregivers) should also be vaccinated. Finally, any healthy person who wishes to be protected from influenza should receive an annual vaccine. Since many office workers are at risk for a worksite epidemic, employers often encourage them to be vaccinated. The vaccination of apparently healthy children may also be warranted because encephalitis and encephalopathy have been reported with increased frequency among children who have an influenza infection.[8]
The Influenza Vaccine
Vaccine Protection
Protection from influenza is dependent on how closely the strains approximate the circulating strains of the virus. Elderly and immunocompromised people may not be as protected as younger adults because their postvaccination antibody titers tend to be lower.[4] Protective antibody levels are achieved in 70% to 90% of immunized healthy adults younger than 65 years of age.[9] The antibody titer begins to decline within 7 months, and, therefore, annual vaccination is needed. The vaccine may reduce the severity and complications that follow the onset of influenza. Therefore, vaccine protection can decrease the risks of illness, hospitalization, and death.
Adverse Reactions and Contraindications
Local reactions, which occur in approximately one third of recipients, include pain, erythema, and induration at the vaccine site. For the first 2 days after the intramuscular injection, the recipient may experience systemic reactions consisting of fever, malaise, and myalgia. Because influenza virus is killed during the manufacturing process, people cannot get influenza from the vaccine. Guillain-Barré syndrome has not been associated with the vaccine since the 1976 swine influenza vaccine. However, Wyeth Laboratories recommends that the vaccine not be administered to persons with a history of Guillain-Barré syndrome.[7] Although the vaccine can be given to people with minor illnesses, persons with acute febrile illnesses should not receive it. Because animal reproduction studies have not been conducted to determine fetal harm from the vaccine, caution should be used when making decisions to give the vaccine to pregnant women. The vaccine contains a small amount of egg protein and therefore is contraindicated for individuals with a severe anaphylactic sensitivity to eggs.
Chemoprophylaxis With Antiviral Compounds
Flu Shots For All Tots
Flu season is on its way, and this year that means flu vaccine
time for young children. For the first time, federal health
officials are recommending that all babies aged six months to two
years be vaccinated against influenza, The Associated Press
reports. The new recommendation comes after research has shown
that children under two years old are as likely to be
hospitalized for complications of flu as people over age 65. U.S
health officials say there is no shortage of flu vaccine for this
year. Although flu outbreaks usually start in December or
January, officials recommend that parents start looking into the
inoculations now, since the vaccine formulated especially for
infants has to be administered in two doses, one month apart, the
AP says. Other high-risk people who should get the flu vaccine
include those over age 50, people with medical conditions that
make them more vulnerable to infection, women who will be more
than three months pregnant, children of any age taking aspirin
therapy, health care workers and people who live or work in long-
term care facilities. Healthy people are urged to wait until
November to get a flu shot, the AP says
