High Immune Response Seen with Novel H5N1 Avian Influenza Vaccine

26 July 2006 (Agence de Presse Medicale for Reuters Health)—A new H5N1 avian influenza vaccine may be filed with regulatory agencies in the coming months, after study results showed that the vaccine elicited a high immune response, even at the lowest dose of antigen tested, vaccine-maker GlaxoSmithKline said.

Early analysis of a clinical trial with 400 healthy volunteers showed that the vaccine elicited a strong seroprotective immune response in >180% of subjects who received 3.8 µg of antigen. “This level of seropro-tection meets or exceeds target criteria set by regulatory agencies for registration of influenza vaccines,” the company added in a statement.

“Efficacy results at these levels of antigen dosage have not been reported for any other H5N1 vaccine in development to date, including those using other adjuvants such as alum,” GlaxoSmithKline continued.

J. P Garnier, GlaxoSmithKline's Chief Executive Officer, said, “These excellent clinical trial results represent a significant breakthrough in the development of our pandemic flu vaccine. This is the first time such a low dose of H5N1 antigen has been able to stimulate this level of strong immune response.”

The study was conducted in Belgium and involved adults between 18 and 60 years old who were vaccinated twice during the course of the trial. Four different levels of antigen dose were tested; 3.8 fig was the lowest dose assessed.

© 2006 Reuters Limited. All rights reserved

Editor's comment. According to a different article, the vaccine will probably cost ∼$7.40, which is the same as a conventional influenza vaccine. GlaxoSmithKline believes that its H5N1 vaccine will work more efficiently than rival ones in development, because of the proprietary adjuvant used in its manufacture (no other information is available). A key challenge in the race to produce a vaccine for millions of people around the world—a vaccine that governments are keen to stockpile—is how to make the maximum number of injections from the minimum amount of antigen. Antigen is produced in chicken eggs in a slow and laborious process. GlaxoSmithKline's vaccine contains just 3.8 µg of antigen, yet >180% of healthy adult volunteers who received 2 doses had a strong immune response.

The level of protection was twice as good at one-half the dose as that of an experimental vaccine produced by Sanofi-Aventis. Sanofi reported good responses with a vaccine using a conventional adjuvant given at 2 doses of 30 mg of antigen. But when the dose was reduced to 7.5 µg, only 40% of people were protected.

U.S. FDA Approves First Once-Daily AIDS Pill

13 July 2006 (Reuters [Susan Heavey and Lisa Richwine])—The first once-daily pill for HIV infection, Atripla, which combines 3 antiretroviral drugs, won US approval, offering patients a more convenient alternative to combination drug therapy.

Atripla contains efavirenz (Sustiva; Bristol-Myers Squibb), a nonnucleoside reverse-transcriptase inhibitor; tenofovir disoproxil fumarate (Viread; Gilead), an acyclic nucleoside; and emtricitabine (Em-triva; Gilead), a nucleoside reverse-tran-scriptase inhibitor.

The 3-drug combination found in Atri-pla is the most commonly prescribed regimen for US patients starting HIV treatment, Dr. Norbert Bischofberger, Gilead's executive vice president of research and development, said in an interview. The new pill “is a really nice advance. You can't make it any simpler,” Bischofberger said adding other possible combination pills are in the works.

Atripla will cost $1150.88 for a 30-day supply, the drugmakers said.

Tenofovir disoproxil fumarate and em-tricitabine are already available in a combination pill called Truvada, which hit the market last year.

The approval also makes the drug available for a US program to fight AIDS in 15 other countries.

The drug's label will include a strong “black box” warning about the risk of lactic acid build-up in the blood. Other adverse effects may include abnormal dreams, hallucinations, and kidney problems. Women who take it should not become pregnant because it may cause birth defects.

In June, the Food and Drug Administration approved another 3-in-1 AIDS pill for use in poor countries under a global relief plan. That product contains generic versions of older HIV drugs, and the combination is not sold in the United States.

U.S. Safeguards Vastly Cut BSE Risk to People—Study

26 July 2006 (Reuters [Christopher Doer-ing])—The US government virtually eliminated the threat of mad cow disease to consumers by requiring the removal of brains, spinal cords, and other high-risk items from older cattle, the Harvard Center for Risk Analysis said.

With only 3 cases of mad cow found in the country, the US Department of Agriculture (USDA) says that the risk of mad cow is very low.

“Removing high-risk tissues, often called specified-risk materials or SRMs, from animals 130 months of age almost completely eliminates potential human exposure,” the center said in an update to its 2003 study, commissioned by USDA

Consumer activists said the government could do more, such as setting a lower age level for SRM removal.

“USDA hasn't followed the most proactive approach,” said Caroline Smith DeWaal, Director of food safety with the Center for Science in the Public Interest. “We've got a ways to go.”

She said in addition to expanding the SRM ban, the USDA must implement a nationwide traceback system to find herd-mates of suspect livestock when there is a disease outbreak.

Added Mike Hansen, a spokesman with Consumers Union: “It does appear that the model is basically designed to tell the USDA what it wants to hear a that doing anything more stringent doesn't get you any further.”

In its report, the center said 2 other USDA measures—banning “downer” cattle too ill to walk and the use of so-called advanced meat recovery equipment—also were helpful, but to a lesser degree than SRM removal.

“SRM removal is it, but there are some other things that increase, that help,” Richard Raymond, the USDA under secretary for food safety, told reporters. “The banning of the downer cattle is one of the things that helps reduce the risk,” he added.

The USDA quickly moved to ban meat from downer animals in the human food supply soon after the United States discovered its first case of mad cow disease in Washington state in December 2003. The rule was temporary, but Raymond said the USDA was working on a final proposal.

The removal of downer cattle reduced human exposure to mad cow disease by ∼3%, the study found.

© 2006 Reuters Limited. All rights reserved

Editor's comment. The human toll from this disease is clearly decreasing. The total number of deaths due to definite or probable variant CJD (vCJD) in the United Kingdom (where the vast majority of cases have occurred) since the onset of the epidemic has been 156, with an overall total of definite or probable vCJD cases (dead and alive) of 161.

The number of deaths due to definite or probable vCJD in the United Kingdom during the 12 months of 2005 was 5. The peak number of deaths was 28 in the year 2000, followed by 20 deaths in 2001, 17 deaths in 2002, 18 deaths in 2003, 9 deaths in 2004, 5 deaths in 2005, and so far 3 deaths in 2006.

China Faces Huge Task in Hepatitis B Fight

25 July 2006 (Reuters)—China still faces an uphill struggle in vaccinating against hepatitis B virus, despite achieving considerable success over the past few years, health officials said.

In China, where 10% of the population, or 120 million people, suffer from chronic hepatitis B, 1 million children per year, mainly in the impoverished west of the country, are not vaccinated on time, they said.

But a push supported by the GAVI Alliance, which is funded by European countries, the United States, and the Bill and Melinda Gates Foundation, has meant that China's immunization rate for new-borns has increased to 90% from 60% in 1999.

“There are still a lot of problems in immunization work. For example, the funding from the government for immunization is far from enough for the demand, and the conditions in some areas are quite poor,” vice health minister Jiang Zuojun told a news conference.

Although it is relatively easy to ensure babies born in hospital are, within 24 h, given their first shot against a disease which can cause liver failure and cancer, reaching children born at home, as often happens in remote areas, remains a problem.

Health officials added that another challenge was reaching tens of millions of migrant workers, who have flocked to the cities from the countryside, hoping to ride the economic boom.

“It's very difficult to manage such a population, and the immunization level for their newborns is very low,” said Yang Weizhong, director of China's Center for Disease Control and Prevention's Disease Control and Emergency Response Office.

The government has set a target of bringing the infection rate in the general population down to 7% by 2010, and fighting hepatitis B is a key part of China's health strategy for the next 5 years, Yang added.

© 2006 Reuters Limited. All rights reserved