Biopeer

New method might lead to rapid development of malaria vaccines

Researchers at the Biochemistry Department of the University of Lausanne, Switzerland and University of Montpellier, France, have discovered a method for the quick development of malaria vaccines. The scientists hoped to develop an antibody-based vaccine for malaria to stop proliferation of the parasite in blood. They turned to the recently sequenced malaria parasite genome and bioinformatics peptide synthesis, using hundreds of short-helical coiled protein segments which are able to maintain their conformation once they are chemically synthesized. In the first round of vaccine selection, all 95 peptides synthesized were recognized by the blood of malaria immune patient donors. Purified human antibodies that are specific to at least a dozen of these peptides could inhibit the growth of the malaria parasite in the body. The researchers say that quick detection would speed up the manufacturing process of vaccines, thereby reducing time and cost to enter new vaccine candidates in clinical trials.

Researchers at the Roswell Park Cancer Institute (RPCI) published a study in the July 23 edition of the Proceedings of the National Academy of Sciences about their discovery of a therapeutic ovarian cancer vaccine. The cancer vaccine is formulated to trigger the antitumor response in the body, which in turn would inhibit the cancer cells that remain after primary treatment. The study evaluated the effect of this vaccine in women with epithelial ovarian cancer. "Further, we detected vaccine-induced immune cells in patients up to 12 months after immunization, suggesting a long-lasting effect," said Kunle Odunsi, of the Gynecologic Oncology and Immunology departments at RPCI.

Researchers in the molecular genetics and microbiology department at Duke University have discovered genetic reasons why a small percentage of people have a natural resistance to HIV. When a person is infected by HIV, viral load rises to a high level before the immune system pushes it down to a stable level. Some people can push the virus to undetectable levels; those who cannot control it progress rapidly to AIDS. "People really vary in their vulnerability to HIV. Some people, despite repeated, high degrees of exposure, will not become infected," said David Goldstein, lead researcher. "And even for those who do become infected, their immune systems are able to control the virus just fine." Researchers estimate up to 10% of people who do become infected will not become sick. Understanding people’s natural resistance to HIV may lead to new HIV vaccines or treatments.

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Side effects from smallpox vaccine linked to genetic factors

The findings of a study published in The Journal of Infectious Diseases revealed that certain adverse events related to smallpox vaccination are linked to genetic factors. Dr. Samuel L. Stanley Jr. and colleagues studied 346 individuals who had undergone smallpox vaccination, out of which 94 developed fevers after vaccination. The researchers analyzed 19 gene clusters (called haplotypes) that are linked to different immune responses to viral infections. The study identified the link between fevers after immunization with live virus particles, as in smallpox vaccine, and specific gene clusters in the interleukin-1 (IL-1) gene complex on chromosome 2, and the interleukin-18 gene on chromosome 11. "Vaccines are the safest and most effective way to prevent a number of very important childhood and adult diseases," said Dr. Stanley. "Our work is designed to identify ways we might make vaccines even more acceptable in the future by discovering ways to further reduce the chance of minor adverse events."

The U.K. Joint Committee on Vaccination and Immunisation (JCVI) is expected to endorse Gardasil, a vaccine against the virus that causes most cervical cancer. The decision by the JCVI is considered delayed by some, as the U.S. Food and Drug Administration (FDA) approved Gardasil last summer. The (JCVI) will start administering the vaccine in 12-year old girls, starting next year. The vaccine protects against infections from the human papilloma virus (HPV), of which two strains – HPV-16 and HPV-18 – account for 70% of cervical cancer. Strains HPV- 6 and HPV-11 account for about 90% of genital warts. Hugh McKinney, spokesperson for the National Family Campaign, was of the opinion that vaccination against a sexually transmitted virus would encourage sexual behavior of minor girls. "I don't think girls are thinking about cancer when they decide whether or not to have sex," said Syed Ahmed, member of the JCVI, in response to similar remarks. "They are more concerned about becoming pregnant or catching chlamydia or gonorrhoea."

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Routine vaccination strategy may work as preventive measure against meningitis

Researchers from the Institut de Recherche Pour le Développement (IRD) claimed that adopting a strategy of routine vaccination with a less effective, but cheaper vaccine could prevent the recurrence of meningitis in children and young people. Polysaccharide vaccine and conjugated vaccine both immunize subjects against meningitis, but polysaccharide vaccine provides only a partial, temporary effect. The study involved two vaccination campaigns conducted with this vaccine by the Senegalese health services. One of the campaigns was carried out in 1996 in eight of the 30 villages in the Niakhar region of Senegal. The second campaign was conducted 1999 in an area hit by a series of epidemics between 1998 and 2000. Using quarterly censuses carried out since 1983, the researchers collected then evaluated data on the response of children’s health to the vaccine. The evaluation enabled the researchers to check the recurrence of meningitis after the 1996 vaccination campaign. Results from the investigation showed that in the villages vaccinated in the campaign, two to three times fewer subjects were recorded as suffering from meningitis. The polysaccharide vaccine could help avoid up to 72% of cases in subsequent epidemics. Although the conjugated vaccine is more effective, it is also 22 to 44 times more expensive than the polysaccharide vaccine. Hence, the researchers are trying to develop conjugated vaccines sold at less than $1 per dose. 

Researchers at the Preston Robert Tisch Brain Tumor Center at Duke University and the University of Texas MD Anderson Cancer Center have found that chemotherapy may actually improve the efficacy of brain tumor vaccines. The study evaluated patients diagnosed with early stage glioblastoma multiforme, who were given tumor vaccine along with the chemotherapy drug temozolomide. Results showed that average survival for patients with newly diagnosed, surgically treated glioblastoma multiforme was 15 months with standard therapy, including chemotherapy. Patients who had received vaccine treatments with chemotherapy survived for a longer period.

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Mixed announcements regarding vaccines

American studies indicate that Varivax, a malarial vaccine, does not last long. The studies reveal that a second dose is needed to keep the disease at bay. This information serves to reassert what researchers already suspected. It was found that people, who had been vaccinated as children but got the disease much later, suffered a lot more and the complications were higher. An adult, who suffered from malaria, was more likely to be hospitalized and the mortality risk was 20 times higher. Due to the conclusions of this study, US Centers for Disease Control (CDC) and the Los Angeles County Department of Health Services have advised that a second shot be given to children between the ages of 4-6. The CDC’s researchers, gathered and analyzed information from 350,000 people from Antelope Valley, California. After analyzing the data, the researchers found that between 1995 and 2004, 11,356 people had had malaria. Of the total number of patients, only 1,080 people had been vaccinated. The researchers, however, are positive about the vaccine. They say that it has helped bring down the chances of children contracting malaria.

Meanwhile, the CDC announced safety data regarding RotaTeq, a rotavirus vaccine. The USFDA (Food and Drug Administration) had received several reports concerning the intussusception after receiving the RotaTeq vaccination. The FDA then notified healthcare professionals about the same. After conducting studies they found that giving the vaccine did not increase your chances of getting intussusception. RotaTeq prevents 74 per cent of rotavirus incidents. The approval of the vaccine is important since RotaTeq is the only authorized vaccine to prevent the rotarvirus disease.

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Vaccines create stir

Researchers from the Saint Louis University Medical Center have determined that administering the flu vaccine through a nasal spray is more effective than injecting it. On comparing the children who had received the flu vaccine through a nasal spray against those who had been injected with it, they found that the former was more effective in 54.9 per cent more cases. However, they do not advocate the spray for children younger than one year and those suffering from asthma as it was observed to cause wheezing. Also, though MedImmune Inc, the makers of this vaccine have applied for approval to the United States Food and Drug Administration (FDA), it has not been granted yet.

In a major setback, the FDA has issued public health notifications for RotaTeq, a diarrhea vaccine for children. It has come to the notice of the FDA that there could be a possible link between RotaTeq use and intussusception, a potentially fatal bowel problem. Since the FDA approved the vaccine in February 2006 to January 2007, 28 babies who had received RotaTeq had developed intussusception. Though these cases have not exceeded the usual number, the FDA has requested parents to report cases of intussusception so that it can be conclusively determined whether the vaccine is the cause for the disease.

Meanwhile, the World Health Organization has granted the prequalification status to Rotarix, a vaccine for rotavirus gastroenteritis in children. GlaxoSmithKline, the manufacturers of the vaccine, stated that this status makes the vaccine eligible for mass vaccination programs. In a positive development, Italy, Canada, Norway, Russia and the UK have come together to formulate and make available vaccines for developing countries. The program, called Advance Market Commitment, is a USD 1.5 billion plan mainly targeting diseases like HIV/AIDS, tuberculosis and malaria. The effort is estimated to save the lives of 5.4 million children by 2030.

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Vaccines bring hopeful news

Continuing its efforts to hinder the spread of AIDS, Uganda has launched trials for a HIV vaccine that will check the mother-child transmission of the virus during breastfeeding. The vaccine has been named Alvac-HIV. The trial is currently in its phase I randomized double-blind stage where 14 babies have been given either the vaccine or a placebo as a control. In this phase, the researchers intend to find out whether the vaccine is safe for babies. Once this is established, they will test its efficacy in stopping the transmission. So far, the trial has met with great success. The final results will be out in mid-2007.

Meanwhile, scientists from America’s National Institutes of Health have developed a vaccine that will destroy the malaria-causing parasite in the mosquito. When the malaria vaccine is administered to a person, it brings about certain changes in his or her immune system. Then, when the mosquito bites a vaccinated person, these changes will eradicate the parasite from the mosquito’s digestive tract. With this vaccine, the researchers aim to make mosquitoes in a particular area free of the parasite so that they cannot spread malaria.

Also, a study conducted at the University of California San Francisco, USA, has determined that a therapeutic cancer vaccine extends the life span of men with asymptomatic metastatic hormone refractory prostate cancer. The vaccine, named sipuleucel-T, proved to hinder the progression of the disease in a double-blind, placebo-controlled phase III clinical trial conducted on 127 patients. Those who received the vaccine had a median overall survival of 25.9 months while it was 21.4 months for the others. The treatment did not have any severe side effects either. With treatment options for this disease generally being limited, the study has renewed hope for these patients.

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Dengue in news again

After India, it’s Pakistan that is now grappling with dengue. As of November 22, a total of 5,235 patients with symptoms similar to dengue fever had been admitted to different hospitals across Pakistan. To date 48 deaths have occurred from dengue fever in Pakistan.

Meanwhile, in India, the Petitions Committee of the Delhi Assembly has held the Municipal Corporation of Delhi and the Delhi Jal Board responsible for the outbreaks of dengue and vector-borne diseases in the capital. The report states that the corporation's failure to effectively de-silt open drainages has worked as breeding grounds for mosquitoes and insects that have given rise to diseases such as dengue, chikangunya and malaria. The government body has not yet reacted to the filed petition.

While Pakistan and India continue to be fraught with dengue worries, some developments in the sphere of dengue vaccine and diagnosis may offer relief in the future. The Pediatric Dengue Vaccine Initiative (PDVI), a program of the International Vaccine Institute (IVI) has decided to work in collaboration with Hawaii Biotech to develop a dengue vaccine for the global prevention of dengue fever. According to Harold Margolis, Director of the PDVI, the primary objective behind this joint venture is to ensure rapid introduction to dengue vaccines into the immunization programs in all affected areas as soon as a vaccine becomes available.

Bio-Rad India, subsidiary of Bio-Rad Laboratories USA, launched India’s first early dengue detection kit called Platelia Dengue NS1 Ag. The common test employed to detect dengue involved identifying the presence antibodies which are produced four to six days after the appearance of the first symptoms. However, this new kit is a time saving device as it checks for virus NS1 antigen which can be traced in the blood stream as soon as the first symptoms of dengue appear.

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Promising vaccines to combat tuberculosis

A new vaccine for tuberculosis (TB) has been developed by researchers from the Oxford University. As a part of the study, a clinical trial was conducted on three groups; the first group was administered the normal BCG (Bacillus Calmette-Guerin) vaccine, the second group was give the new vaccine M*A 85 A while the third group was given M*A 85 A, compounded with BCG. The results revealed that the new vaccination was safe and produced large number immunity increasing T-cells. The study also concluded that the new vaccine produced more T-cells in patients who were given BCG vaccine leading the scientists to hypothesize that the new vaccine when combined with BCG was substantially more effective as a defense strengthening mechanism. Although the vaccine does not assure complete prevention from tuberculosis, it works to increase the immunity power within the body to ward off a TB infection in patients contracting it for the first time.

Crucell N V in a joint venture with The AERAS Global TB Vaccine Foundation has announced the start of its phase I clinical trial for AdVac®-based tuberculosis vaccine. It was further revealed that the clinical trial to be conducted on 24 healthy volunteers will be an open-label study testing the vaccine on a dose escalation trial basis. The other testing parameters for the new vaccine will focus on the safety, tolerability and immunogenicity aspects.

Meanwhile, the United Nations (UN)-backed Global Fund to Fight AIDS, Tuberculosis and Malaria has approved a grant of USD 847 million dollars. The grant amount will be used in realizing 85 projects that deal with combating AIDS, TB and Malaria across 63 countries.

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Possible influenza and malaria vaccines raise hopes

A vaccine being developed for H5N1 virus has been found to protect against other variations too. Sanofi Pasteur, a unit of Sanofi–Aventis stumbled upon this when it conducted fresh tests on the experimental vaccine. In a statement, Sanofi affirmed that the positive results proved that it is possible to formulate a vaccine that would induce “the formation of antibodies capable of neutralizing the most recent strains of the H5N1 virus”. These strains include the ones that have been making the rounds of Southeast Asia.

Meanwhile, the fight against malaria got much needed encouragement when an experimental malaria vaccine showed promising results. According to reviewers from the Cochrane Library, tests showed that the vaccine decreased the number of clinical malaria episodes by 26 per cent for up to 18 months after vaccination. The number of episodes in children reduced by 58 per cent. The vaccine, RTS,S assaults the malaria causing parasite Plasmodium falciparum when it has just entered the human body with a mosquito bite. Scientists from the Walter Reed Army Research Institute developed the vaccine in association with GlaxoSmithKline. A second vaccine, MSP/RESA or Combination B attacks the parasite at a later stage of the disease and the reviewers see much promise in it too.

American scientists from the National Institutes of Health (NIH) have developed a vaccine for the deadly 1918 influenza virus, nearly a hundred years after it wrought havoc. The vaccine was found to be effective when tested on mice. Mice injected with the vaccine did not succumb when exposed to a reconstructed 1918 virus. The researchers hope that this vaccine will provide a successful basis for formulating vaccines against other influenza strains.

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Asian neighbors rev up fight against Hepatitis B

In a major relief to those suffering from Hepatitis B in India, the first homegrown Hepatitis-B Vaccine called Elovac-B has been launched by the Human Biologicals Institute (HBI). With India emerging as a global medical hub—world class health care is available here at an affordable price—this launch is yet another milestone towards cementing the country’s numero uno position in the sphere. The Andhra Pradesh Finance minister, Rosaiah said on the occasion while complimenting HBI that immunity has been made affordable with the launch of Elovac-B. “There’s a need to achieve 100 per cent immunization among children and for that the Government as well NGOs should come forward to eliminate such diseases.” The vaccine, which has been prepared by HBI at a state-of-the-art plant, offers best purity and ensures best protection. The purity of Hepatitis-B surface antigen exceeds the purity specification provided by regulatory authorities.

In neighboring China, the Ministry of Health has begun a yearlong nationwide survey of the Hepatitis B situation. The survey will run till September 2007, and involves collecting blood serum samples, conducting lab tests, filing archives and making reports for future control plans. With about 100 million people suffering from Hepatitis B in China (of these approximately 20 million are chronic patients), the situation is indeed grim. Further, the government has started a two-year program aimed at preventing the spread of Hepatitis B from mother to child in four counties of Shaanxi and Gansu provinces.

The program will be first carried out in rural areas for women of childbearing age. The USD 200,000 program aims to teach nearly 340,000 women of childbearing age and nearly 600 grassroots doctors in pilot counties how to prevent Hepatitis B.

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