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A Measles Mystery: How Could the Vaccine Prevent Deaths from Other Diseases Too?

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By Michael Mina, Postdoctoral researcher at Princeton University and MD/PhD candidate at Emory University

If infectious diseases were a monarchy, measles might be king. Not only does measles reign among the most contagious diseases known to man – likely to infect any non-vaccinated individual who stands in the same room as an infected person – measles has long been known to be one of the great killers of children. Before vaccination, measles was responsible for millions of childhood deaths. Today it remains a cause of great illness and death in low-resource countries, killing over 140,000 children worldwide every year. [Read more…]

Rotavirus Vaccine Leads to Lower Doctor Visits and Health Care Costs

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Vaccinating infants against rotavirus has resulted in dramatic decreases in health care use and treatment costs for diarrhea–related illness in U.S. infants and young children, according to a new study by the Centers for Disease Control and Prevention. The study is published in the current issue of the New England Journal of Medicine.

“This is good news for parents and our health system overall,” said Dr. Umesh Parashar, medical epidemiologist and team leader for the Viral Gastroenteritis Team in CDC′s Division of Viral Diseases. “Rotavirus vaccine is one of the most effective ways to prevent severe diarrhea–related illness in young children and keep them healthy.”

Rotavirus is a major cause of severe diarrhea in infants and young children in the United States. Before vaccines were introduced in 2006, rotavirus was responsible for about 400,000 visits to doctor′s offices, 200,000 emergency room visits, 55,000 to 70,000 hospitalizations, and 20 to 60 deaths each year in children under 5 years old.

RotaTeq and Rotarix, the two U.S. licensed rotavirus vaccines, were 85 to 98 percent effective at preventing severe rotavirus disease in clinical trials in middle and high income countries, including the United States.

This new study used data from a large U.S. insurance database for 2001 to 2009 to assess rotavirus vaccine coverage and its impact on health care use and treatment costs for diarrhea–related illness in children under 5 years old. The study examined direct benefits to vaccinated children and indirect protective benefits to unvaccinated children. National declines in health care use and treatment costs were estimated by applying the declines seen in this study to children under 5 years old in the U.S population.

By the end of 2008, 73 percent of children under 1 year of age, 64 percent of 1–year–olds, and 8 percent of 2– to–4–year–olds had received at least one dose of rotavirus vaccine. Rotavirus–related hospitalizations decreased substantially compared with pre–vaccine levels in children under 5 years old—75 percent decline for 2007–2008 and 60 percent decline for 2008–2009.

Vaccinated children had 44 to 58 percent fewer diarrhea–related hospitalizations and 37 to 48 percent fewer emergency room visits for diarrhea than unvaccinated children during the 2008 and 2009 rotavirus seasons (January to June). Even in unvaccinated children, there were substantial declines in health care use during the 2008 rotavirus season compared with pre–vaccine levels—showing indirect protective benefits.

The study estimated that about 65,000 hospitalizations of children under 5 years old from 2007 to 2009 were averted nationally with a health care cost savings of about $278 million.

“This study provides more evidence that vaccinating against rotavirus substantially reduces suffering and health care costs for this common childhood illness,” said Dr. Mark Pallansch, director of CDC′s Division of Viral Diseases. “As more children get vaccinated against rotavirus, we expect to see even greater reductions in disease among all age groups.”

Source: CDC

Flu Prevention for Children and Teens – Report

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Although children and teenagers rarely die from flu–related causes, many of the deaths could have been prevented if the children had been vaccinated against the flu, according to a report by the Centers for Disease Control and Prevention.

The study reports 115 influenza–associated deaths of people younger than 18, from September 2010 through August 2011 and highlights the importance of both annual vaccination and rapid antiviral treatment.

“It′s vital that children get vaccinated,” said Dr. Lyn Finelli, chief of the CDC′s Surveillance and Outbreak Response Team. “We know the flu vaccine isn′t 100 percent effective, especially not in children with high risk medical conditions. That′s why it′s essential that these two medical tools be fully utilized. Vaccinate first; then use influenza antiviral drugs as a second line of defense against the flu. Right now we aren′t fully using the medical tools at our disposal to prevent flu illnesses and deaths in children.”

The study in CDC′s Morbidity and Mortality Weekly Report provides details on the deaths. Since 2004, states have been required to report influenza-associated deaths in children and teenagers, giving the CDC a chance to look closely at factors that can increase risk.

Among the most notable findings was the infrequent use of the most important influenza prevention measure – vaccination. Despite a recommendation for vaccination of all children 6 months of age and older having been in place since 2008, only 23 percent of the 74 children older than six months with a known vaccination history had received their flu vaccine last season.

While many people believe that healthy children can withstand a bout of flu, this is not always the case. About half of the children who died last season were previously healthy and did not have a medical condition that would put them at risk for flu complications. However, the report underscores the fact that young age in itself is a risk factor. The report identified that 46 percent of the children who died were younger than 5 years and 29 percent were younger than 2 years.

The other half of the children who died did have a medical condition that predisposed them to being at greater risk of flu complications. Of 57 children with a medical condition, 54 percent had a neurological disorder, 30 percent had pulmonary disease, 25 percent had a chromosome or genetic disorder and 19 percent had congenital heart disease or other cardiac disease.

The report also identified issues with the use of antiviral drugs, which provide effective treatment for influenza. Of the 94 children who died in a hospital or emergency department, only 50 percent were prescribed antiviral drugs. Since the 2009 H1N1 pandemic especially, CDC has recommended immediate treatment with influenza antiviral medications in severely ill patients with suspected flu.

Another report in the Sept. 16 MMWR provides a summary of influenza activity from mid–May to the beginning of September. “If trends in that report continue,” Finelli says, “we should have a vaccine that will offer good protection against the viruses we expect will circulate this season.”

This season′s influenza vaccine protects against three influenza viruses, the 2009 influenza A (H1N1) virus, an influenza A (H3N2) virus, and an influenza B virus. These are the same three flu virus strains that were circulating in 2010–2011 – just the eighth time since 1969 this phenomenon has occurred. Moreover, it is important to note that vaccine immunity wanes over time so CDC is recommending that everyone get vaccinated this season, even if they got vaccinated last season, in order to be optimally protected.

Source: CDC

Vaccination Controversy Spills Over to Video Sharing Site YouTube

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There is a growing debate over the necessity of the number of vaccines administered today. The controversy often surrounds a number of issues, such as pharmaceutical company lobbying to require administration of vaccinations that critics say have not undergone adequate testing.

For example, many states have pending bills that would require young girls to be vaccinated against HPV with Merck’s Gardasil. Currently only Virginia has passed a bill, as controversy has stalled bills in other states. The Virginia bill requires girls entering the sixth grade to be vaccinated, though it allows parents to opt their daughters out.

In February, 2007, Merck & Co. discontinued its lobbying of state
legislatures in an attempt to make it mandatory for girls to be inoculated with
Gardasil.

Others argue that over-vaccination will have long term detrimental effects on human immune systems. In the Journal Immunology Today researchers wrote:

Modern vaccinations, fear of germs and obsession with hygiene are depriving the immune system of the information input upon which it is dependent. This fails to maintain the correct cytokine balance and fine-tune T-cell regulation, and may lead to increased incidences of allergies and autoimmune diseases. If humans continue to deprive their immune systems of the input to which evolution has adapted it, it may be necessary to devise ways of replacing it artificially.

In a study published today in the Journal of the American Medical Association, University of Toronto researchers have uncovered widespread misinformation in related videos on YouTube.

The researchers, Dr. Kumanan Wilson and Dr. Jennifer Keelan, analyzed 153 videos about vaccination and immunization on YouTube, a popular online video-sharing site. Researchers found that more than half of the videos portrayed childhood, HPV, flu and other vaccinations negatively or ambiguously.

Of those videos, researchers report that about 45 per cent contained messages that contradict the 2006 Canadian Immunization Guide, which provides national guidelines for immunization practices. The Canadian recommendations are similar to guidelines from the American Centers for Disease Control and Prevention.

"YouTube is increasingly a resource people consult for health information, including vaccination," says first author Keelan, an assistant professor in U of T’s Department of Public Health Sciences. "Our study shows that a significant amount of immunization content on YouTube contradicts the best scientific evidence at large. From a public health perspective, this is very concerning."

The research team also found that videos skeptical of vaccinations—many of them highly provocative and powerful—received more views and better ratings by YouTube users than those videos that portray immunizations in a positive light.

"Health care professionals need to be aware that individuals critical of immunization are using YouTube to communicate their viewpoints and that patients may be obtaining information from these videos," says Wilson, senior author and an associate professor with U of T’s Department of Medicine. "YouTube users also need to be aware of this, so they can filter information from the site accordingly."

"The findings also indicate that public health officials should consider how to effectively communicate their viewpoints through Internet video portals," Wilson says.


Sources:

  • Journal of the American Medical Association, December 5, 2007
  • Universtiy of Toronto
  • Immunol Today, 1998 Mar;19(3):113-6.