Tag Archives: vaccines
Two new studies presented at the 2012 Canadian Cardiovascular Congress suggest that heart patients who get flu vaccines have lower risks of heart attacks and strokes and fewer episodes of irregular heart rhythms.
Some cautions apply. Both studies were small and preliminary. Researchers agree that they should be repeated with more people and published in peer-reviewed journals before flu vaccines can be claimed to cut heart risks.
“The current body of evidence makes it difficult for us to know for sure whether influenza vaccination reduces cardiovascular events,” says Jennie Johnstone, MD, an assistant professor in the division of infectious diseases at McMaster University in Toronto, Canada. She was not involved in the research.
Johnstone says the new studies are intriguing but should be followed up.
Flu Vaccine and Heart Risks
For the first study, researchers pooled data from four published clinical trials with 3,200 patients that tested flu vaccines against placebo shots. About half the patients in the studies had heart disease. The other half had no history of heart problems.
Patients in the studies were randomly assigned to get flu vaccines or placebos. Over one year, there were 187 major cardiovascular events. Those events included heart-related deaths and non-fatal heart attacks, strokes, emergency heart procedures, hospitalizations for heart failure, or sudden chest pain.
Overall, about 7.8% of the people who didn’t get flu vaccines had a major heart-related event over the course of the next year compared to 4.3% of those who did get flu vaccines, a reduction in risk of almost 50%. Stated another way, researchers estimate that one major heart-related event is prevented for every 34 people who get vaccinated for flu.
“These are very provocative findings. If I could give you a pill that would cut your risk of heart problems in those with either established heart disease or at risk for heart disease in half, I’m pretty sure everybody would be taking that medication,” says researcher Jacob A. Udell, MD, MPH, a clinical investigator at Women’s College Hospital in Toronto, Canada.
The CDC advises all adults, including adults with underlying conditions like diabetes and heart disease, to get an annual flu vaccine. Still, most don’t. According to the CDC, only about 40% of adults were vaccinated against the flu during the last flu season.
For the second study, researchers surveyed 230 patients at the same hospital who all had implanted cardiac defibrillators (ICDs), devices that shock the heart when it goes into dangerous, irregular rhythms.
Patients with ICDs tend to get more jolts from those devices during the winter months, and doctors wondered whether that might have something to do with the flu.
CDC Says Most Kindergartners Get Vaccinated, but Improvement Is Needed
Aug. 23, 2012 — Most kindergartners are up to date with their vaccines, but federal immunization goals nevertheless remain unmet, the CDC says.
According to a CDC report, the average number of kids who have been vaccinated for measles, mumps, and rubella is 94.8%. Health officials have set their target at greater than 95%.
“Coverage is not the way it should be,” says Jaime Deville, MD. Deville is a professor of pediatric infectious diseases at UCLA’s Mattel Children’s Hospital. He reviewed the report for WebMD.
“This report really confirms what’s already well known,” he says.
The report’s authors point out that vaccine rates vary significantly from state to state. The five states that are doing the best job of vaccinating kids against measles, mumps, and rubella (MMR) are:
- Texas 99.3%
- Mississippi 99.2%
- Nebraska 99%
- Maryland 98.7%
- Louisiana 98.1%
The five states that need the most improvement when it comes to MMR vaccines are:
- Colorado 86.8%
- Pennsylvania 86.9%
- Kansas 88.2%
- Idaho 89.2%
- North Dakota 90.6%
Tetanus, Diphtheria, and Other Vaccines
Forty seven states, the District of Columbia, and five other areas reported their vaccine numbers. The city of Houston submitted its own figures, which were the highest reported, at 99.5% for MMR. Figures for Wyoming, New Hampshire, and New Jersey were not available.
California, the state where Deville teaches and practices, met the 95% goal for only two of the vaccines: chickenpox and hepatitis B.
“Our coverage is really not ideal,” says Deville. He says the number of children in his state who were granted exemptions from vaccines for medical, religious, or philosophical reasons is too high for comfort.
“We see there are 12,000 out of the half million kindergarten age kids here,” says Deville. “That’s a sizable percentage that right off the bat won’t be vaccinated.”
Exemptions From Immunization
Overall, according to the report, 1.5% of children were granted exemptions from vaccinations. That figure varied dramatically from state to state. Mississippi, which does not allow religious or philosophical exemptions, had an exemption rate below 0.1%, the lowest number in the country. Alaska granted exemptions to 7% of its children. Arkansas reported the largest increase in exemptions from the previous year; Nebraska reported the steepest decline.
For the most part, the percentages reported reflect statewide averages. However, the report’s authors point out the need to focus on local rates of immunization that might get overlooked when focusing on the big picture.
“Since exemptions cluster geographically, there might be smaller areas and schools where low levels of immunization could sustain ongoing measles transmission after importation from other countries,” the report states.
Sleeping Less Than 6 Hours Nightly Linked to Lower Immune Response, Researchers Find
Aug. 1, 2012 — People who regularly get more than seven hours of sleep a night are more likely to respond to vaccination against hepatitis B compared to those who get in less than six hours, according to new research.
The differences were surprising, says researcher Aric Prather, PhD, a clinical health psychologist and Robert Wood Johnson Foundation Health & Society Scholar at the University of California, San Francisco, and the University of California, Berkeley.
“People who slept less than six hours on average were 11.5 times more likely to be unprotected [after the vaccine] than those who slept more than seven hours,” he says.
He looked at the immune response to the hepatitis B vaccine in healthy adults.
Hepatitis B, a serious infection that affects the liver, is the cause of death each year for about 2,000 to 4,000 in the U.S., according to the CDC.
The study is published in Sleep.
Sleep & Vaccines: Details
Prather assessed 125 men and women, aged 40 to 60, who got the vaccine.
He first tested them to be sure no one had been exposed to the hepatitis B virus.
The hepatitis B vaccine includes two doses given a month apart. Those are followed by another dose at six months.
The men and women wore a wrist device known as an actigraph to track sleep. Prather asked them to complete sleep diaries. He evaluated sleep duration, efficiency, and sleep quality.
“We measured antibody response just before the second vaccine and just before the third, and then six months after the series was over,” he says.
By that time, a full response is expected.
About 15% of those vaccinated did not achieve full protection six months after the series ended, he found.
He looked at sleep habits and found a link. “What we found was, people who slept fewer hours on average produced fewer antibodies to the vaccine,” Prather says.
Prather stresses that he found a link, not cause and effect.
However, he sees several ways in which sleep might affect antibody response. Sleep loss is linked to fluctuations in immune processes important to producing antibodies, for instance.
It’s too soon and too simple, Prather says, to tell people to get a good night’s sleep before a vaccination.
He found sleep habits over time, not just around the vaccine time, to be linked with a response.
More research is needed, he says.
Sleep & Vaccines: Perspective
The new findings, which looked at people’s natural sleep habits, are strengthened by previous studies in the lab finding similar results when people’s sleep was manipulated, says Firdaus Dhabhar, PhD, associate professor of psychiatry and behavioral sciences at Stanford University School of Medicine.
He reviewed the study findings.
“It is an important demonstration of how the duration of sleep in the participants’ natural environment is related to the strength of their antibody response following vaccination, which is an index of how well protected they might be if actually exposed to the pathogen,” he says.
MONDAY May 7, 2012 — Pre-teens living in states that require vaccinations for incoming middle school students are more likely to be immunized than those in states without such requirements, a new study finds.
Current vaccine guidelines from the U.S. Centers for Disease Control and Prevention recommend that boys and girls aged 11 to 12 receive three immunizations or boosters: tetanus/diphtheria/pertussis (TdaP); meningococcal conjugate; and three doses of the human papillomavirus (HPV) vaccine.
In 2008-2009, 32 states required TdaP and three required meningococcal conjugate. One state, Virginia, required HPV vaccination for girls during those years.
About 80 percent of kids aged 13 to 17 received the recommended TdaP vaccine in states that required vaccination for middle school entry compared to 70 percent of kids in states that didn’t require it. For meningococcal vaccine, those rates were 71 percent versus 53 percent. Researchers did not report HPV vaccination rates in Virginia versus elsewhere.
“State requirement for vaccines for middle school entry does have a positive influence on vaccination coverage. Adolescents in their states are more likely to have received these vaccines,” said study co-author Shannon Stokley, a CDC epidemiologist.
The study was released online May 7 and is to be published in the June print issue of Pediatrics.
School vaccination requirements stretch all the way back to 1855, when Massachusetts became the first state to require smallpox vaccine for school entry, according to background information in the article. Over the decades the number of vaccines required expanded, the majority of which need to be received before entering kindergarten.
More recently, many states have mandated that pre-teens have certain vaccines for entering middle school.
“Vaccines are vital to the health of the adolescent. They are very, very important, and we’ve seen from the state-by-state variations that when you place requirements for vaccinations on school entry you increase the rate that parents will seek vaccinations,” said Dr. Carrie Byington, a member of the American Academy of Pediatrics’ Committee on Infectious Diseases and a professor of pediatrics at the University of Utah School of Medicine.
Yet, even state mandates don’t mean every child will be vaccinated. Every state allows a medical exemption for children, and 48 states plus the District of Columbia also allow either religious or philosophical exemptions, while some allow exemptions for both reasons, Stokley said.
Only West Virginia and Mississippi do not allow non-medical exemptions, she added.
Instead of mandates, many states require that schools or public health departments inform parents about the diseases the vaccines protect against and the current vaccine recommendations. However, the study found states that offered education had no better vaccine rates than those that didn’t.
That doesn’t mean education doesn’t matter, Stokley said.
And though vaccine mandates appear to work, “state requirements are just one strategy to increase immunization,” Byington noted.
Other strategies that can boost vaccination rates include ensuring that kids have access to vaccines and making sure that pediatricians advise parents about the shots, she said. Research has shown that parents trust pediatricians regarding vaccines and are more likely to get their kids vaccinated if the pediatrician recommends it.
For middle schoolers, the vaccines protect against several serious, and even deadly, diseases, including diphtheria, a highly contagious bacterial disease that effects the respiratory system and can lead to swelling of the heart muscle tissue, heart failure and death; tetanus, a bacteria found in the soil that can enter the body through a deep cut and lead to months of serious, painful muscle spasms and lockjaw; and pertussis, or whooping cough.
In 2010, California saw the worst outbreak of whooping cough in 50 years, leading to more than 27,000 people sickened and the deaths of 10 infants. The outbreak led to urgent calls for parents to keep their children’s pertussis vaccines up to date.
Meningococcal disease is a leading cause of bacterial meningitis, an infection around the brain and the spinal cord that kills about one in 10 people who contract it, according to the CDC. “Meningitis is a very serious disease. A person can seem fine, and within hours all of a sudden they can be very ill and potentially die,” Stokley said.
Human papillomavirus is a common virus among people in their teens and early 20s and is spread during sex, potentially causing genital warts in men and women. Certain strains cause cervical cancer in women and also anal cancer, Stokley said.
Check out the recommended vaccine schedule for kids and adults at the U.S. Centers for Disease Control and Prevention.
Posted: May 2012
MONDAY April 2, 2012 — Measles vaccines don’t increase the risk of febrile seizures in children ages 4 to 6, according to a new study.
Febrile seizures are brief, fever-related convulsions that are not fatal and do not lead to brain damage, epilepsy or other seizure disorders.
The study, conducted by the Kaiser Permanente Vaccine Study Center and funded by the U.S. Centers for Disease Control and Prevention, looked at data from nearly 87,000 children ages 48 to 83 months who received the measles-mumps-rubella-chickenpox (MMRV) vaccine; the MMR vaccine plus the varicella vaccine for chickenpox, administered separately but on the same day; or either the MMR or varicella vaccine alone.
There was no increased risk of febrile seizures among the children during the six weeks after they received any of the vaccinations, according to the study, which appears in the current issue of the journal Pediatrics.
“The results provide reassuring evidence that neither MMRV nor MMR plus V appear to be associated with an increased risk of post-vaccination febrile seizures in this 4-to-6 age group,” lead author Dr. Nicola Klein, co-director of the Kaiser Permanente Vaccine Study Center, said in a news release.
In the United States, children receive two doses of MMR and varicella vaccines. The first is given between ages 1 and 2 and the second between ages 4 and 6.
A previous study found that children ages 1 to 2 who received the MMRV vaccine were twice as likely to have a febrile seizure seven to 10 days after vaccination than those who received MMR plus V.
The researchers noted that febrile seizures typically occur in children ages 6 months to 5 years, and the incidence of these seizures peaks at about 18 months of age.
“As febrile seizures are generally much less likely to occur among 4- to 6-year-old children, it is not surprising that we did not detect increased febrile seizures following MMRV or MMR plus V among 4- to 6-year-olds,” Klein said.
“Families of 4- to 6-year-olds can be reassured from this study that the combination MMRV vaccine is safe,” said Dr. Bruce Hirsch, associate chairman for clinical services at North Shore University Hospital in Manhasset, N.Y.
“Febrile seizures are scary; the child develops a high fever and convulses,” he said. “The condition is surprisingly common and can occur after colds and other viral infections.”
The U.S. National Institute of Neurological Disorders and Stroke has more about febrile seizures.
Posted: April 2012