The fewer adverse events associated with acellular pertussis vaccines compared with whole-cell pertussis vaccines may come at the cost of slightly less protection from pertussis infection, according an analysis by Stephen B. Lambert, MBBS, PhD, a scientist at Queensland Children’s Medical Research Institute, and his colleagues. Image: Kris Kamusinski, Herston Multimedia Unit, Queensland Health
Acellular pertussis vaccines, which have become favored over whole-cell pertussis vaccines because they are associated with fewer adverse events, may offer children less protection from pertussis, according to a study published in JAMA today.
Ongoing pertussis outbreaks in the United States, Australia, and other parts of the world have prompted speculation about whether changes in pertussis bacteria, inadequate vaccination rates, or other factors might be driving these outbreaks. To probe the role of the shift from whole-cell pertussis vaccines to acellular pertussis vaccines in the 1990s, Australian scientists compared the reported rates of pertussis infection among 58 233 children born in 1998 who were vaccinated with the acellular vaccine, with the whole-cell vaccine, or with some combination of the 2 over the course of the 3-dose vaccination regimen. They found that the average annual rate of pertussis infection between 1999 and 2008 was more than 2.5 times higher among those who received 3 doses of the acellular vaccine than among those who received 3 doses of the whole-cell vaccine (13.2 vs 5.2 infections per 100 000 per year).
Stephen B. Lambert, MBBS, PhD, a scientist at Queensland Children’s Medical Research Institute and one of the coauthors of the study, discussed the implications of these findings with news@JAMA via e-mail. Continue reading
Screening with electrocardiography for predicting heart problems in asymptomatic adults at low risk for heart events should not be performed, recommends the US Preventive Services Task Force. (Image: JAMA, ©AMA)
Adults at low risk for heart attack and other coronary heart disease events and who have no symptoms of heart disease should not be routinely screened with resting or exercise electrocardiography (ECG), according to the US Preventive Services Task Force. The recommendation, appearing today in the Annals of Internal Medicine, is an update to the task force’s similar 2004 statement that considers studies on the topic published since that time.
Coronary heart disease is the leading cause of death in the United States for both men and women, accounting for nearly 40% of all deaths annually. Each year more than 1 million people in the United States experience nonfatal or fatal heart attacks or sudden death from heart disease.
The conventional tool used by physicians to assess a patient’s heart disease risk is the Framingham Heart Study risk assessment tool, which helps identify individuals at high, intermediate, or low risk of having a heart event in the next 10 years based on such factors as age, sex, total cholesterol and high-density lipoprotein cholesterol (HDL) levels, systolic blood pressure, and smoking. Those at low risk have a 10% or less chance of having a heart event over the next 10 years. At issue is whether ECG screening would provide information that would enable them to identify additional patients at risk and make it possible to treat such patients and further reduce the number of heart attacks or sudden cardiac death. Continue reading
New research shows that early treatment for HIV infection is a cost-effective way to reduce transmission of the virus. (Image: Craig Hill/iStockphoto.com)
New data from a landmark clinical trial that established early treatment for HIV infection as an effective way to prevent transmission of the virus now show that this treatment-as-prevention approach is cost-effective, too.
Presented today at the XIX International AIDS Conference in Washington, DC, the findings are from the HIV Prevention Trials Network (HPTN) 052 study of serodiscordant couples. The trial enrolled 1763 couples, most heterosexual, at 13 sites in Africa, South America, Asia, and the United States. When enrollment began in 2005, infected partners had CD4 cell counts between 350 and 550 cells/mL. The couples were randomly assigned to 1 of 2 groups: immediate antiretroviral treatment (ART) for the infected partner or treatment delayed until the infected partner had a CD4 cell count below 250 cells/mL or an AIDS-defining illness. Data released last year showed that early treatment led to a 96% reduction in HIV transmission to uninfected partners.
Those findings led to revisions in US and World Health Organization (WHO) treatment guidelines but also raised questions about the cost-effectiveness of early treatment. So HPTN 052 investigators used a computer simulation to estimate the economic consequences of their clinical trial results. They produced cost-effectiveness models based on trial results from South Africa and India to determine whether regional economic differences would change the conclusions. Continue reading
People infected with both hepatitis C virus (HCV) and HIV are more likely than people infected only with HCV to experience a severe worsening of liver disease, even if they are receiving anti-HIV drugs. (Image: RapidEye/iStockphoto.com)
Washington, DC—Even when they are receiving anti-HIV drugs, people who are infected with both HIV and hepatitis C virus (HCV) are more likely than people who are infected only with HCV to experience a severe worsening of HCV-related liver disease and death, according to research reported here at the International AIDS Conference.
About one-quarter of individuals who are infected with HIV also have HCV infection. According to the US Centers for Disease Control and Prevention, HIV coinfection more than triples the risk for liver disease, liver failure, and liver-related death from HCV. Continue reading
Aaron Carroll, MD, MS
Last week, the House Appropriations subcommittee on labor, health and human services, and education approved a spending bill, which moves along this week to the full committee for consideration and possible amendments. Then, it’s on to a vote in the House of Representatives.
The bill is generating a fair amount of attention because it takes some drastic steps with respect to government funding of research. Specifically, per Academy Health: Continue reading
Two major trials are under way to study whether a vaginal ring designed to remain in place for a month while it continuously releases a potent anti-AIDS drug will protect women against HIV infection.
Washington, DC—Two large trials are now under way in Africa to test whether a vaginal ring containing a potent antiretroviral drug will prevent HIV infection in women, researchers announced here at the International AIDS Conference.
The ring, a silicone matrix containing the antiretroviral drug dapivirine, is designed to remain in place for a month while it continuously releases the drug to the surrounding vaginal tissue.
The option of a discreet and long-acting HIV prevention method would be especially welcome in sub-Saharan Africa, where the ring is being tested. About half of the more than 34 million people living with HIV worldwide are women; in sub-Saharan Africa, nearly 60% of HIV-infected adults are women. Most acquire the infection through unprotected sex; many have few options to protect themselves when a sexual partner refuses to use a condom. Continue reading
David Cutler, PhD
Findings from a study reported just last week have major implications for the future of medical care. The study evaluated a new payment model called the Alternative Quality Contract (AQC), devised by Blue Cross Blue Shield of Massachusetts. Unlike payment arrangements that involve reimbursing physicians for each test and procedure performed and disputes over those rates, the AQC gives groups of physicians a cost target for their patients as a whole. If medical costs come in below the target and quality of care is high, physicians earn a bonus. If costs exceed the target, physicians suffer financially. Because Blue Cross Blue Shield of Massachusetts is so large, the AQC is a big part of the medical system in Massachusetts.