A simplified method of giving rabies vaccine

A simplified economical method of giving rabies vaccine is just as effective as the expensive standard vaccine regimen at stimulating anti-rabies antibodies.

A clinical trial in healthy volunteers has found that a simpler and cheaper way of using rabies vaccines proved to be just as effective as the current most widely used method at stimulating antibodies against rabies. The trial is published in this week's PLoS Neglected Tropical Diseases.

Dr Mary Warrell (Centre for Clinical Vaccinology and Tropical Medicine, University of Oxford, United Kingdom) and colleagues, who conducted the trial with a vaccine in routine use, say that the simplified method has the advantages of requiring fewer clinic visits, being more practicable, and acceptable, and having a wider margin of safety, especially in inexperienced hands. It would therefore, they say, be "suitable for use anywhere in the world where there are financial constraints, and especially where two or more patients are likely to be treated on the same day."

All human deaths from rabies result from failure to give adequate prophylaxis. After a rabid animal bite, immediate wound cleaning, rabies vaccine and injections of anti-rabies antibody (immunoglobulin) effectively prevent fatal infection. But anti-rabies immunoglobulin is very rarely available in developing countries, and so prevention relies on giving people bitten by rabid animals effective vaccine treatment.

The vaccines that are currently approved by the World Health Organization, which are usually injected into the muscle, are prohibitively expensive, and so are unaffordable in developing countries. In Africa, for example, the average cost of an intramuscular course of vaccine is $US 39.6, equivalent to 50 days' wages.

Two economical regimens, involving injecting small amounts of vaccine into the skin (intradermally) at 2 or 8 sites on the first day of the course, with subsequent booster doses are available in a few places. With the 8-site method, a large dose of vaccine is given on the first day only, whereas with the 2-site method the same dose is divided between the first and third days, entailing an extra visit to the clinic. However, practical or perceived difficulties have restricted widespread uptake of these economical methods. Dr Warrell and colleagues therefore set out to test a new, similar simplified regimen, involving injections at 4 sites on the first day.

They vaccinated healthy volunteers to compare the antibody levels induced by the 4-site intradermal regimen with those induced by the current 2-site and 8-site intradermal regimens and the "gold standard" intramuscular regimen favored internationally. All of the economical intradermal regimens worked just as well as the intramuscular method at stimulating anti-rabies antibodies.

The authors conclude that the results provide sufficient evidence that the simplified 4-site regimen now meets all the criteria necessary for its recommendation for use wherever the cost of vaccine is prohibitive.

Citation: Warrell MJ, Riddell A, Yu L-M, Phipps J, Diggle L, et al. (2008) A Simplified 4-Site Economical Intradermal Post-Exposure Rabies Vaccine Regimen: A Randomised Controlled Comparison with Standard Methods. PLoS Negl Trop Dis 2(4): e224. doi:10.1371/journal.pntd.0000224

Source: Public Library of Science

Related stories:

Jefferson immunology researchers halt lethal rabies infection in brain
While rabies, an ancient scourge that still kills 70,000 every year in developing countries worldwide can be combated with a series of vaccines today, it nearly is always fatal when it reaches the brain.
Scientists find rabies-based vaccine could be effective against HIV
Rabies, a relentless, ancient scourge, may hold a key to defeating another implacable foe: HIV. Scientists at Jefferson Medical College in Philadelphia have used a drastically weakened rabies virus to ferry HIV-related proteins into animals, in essence, vaccinating them against an AIDS-like disease. The early evidence shows that the vaccine – which doesn’t protect against infection – prevents development of disease.
Cell removal technique could lead to cheaper drugs
Researchers at the University of Edinburgh have pioneered a simple way to remove dead cells from cell cultures used to make protein-based drugs, which are increasingly prescribed to treat a range of illnesses.
China sees spike in rabies cases
A new Chinese study has reported a dramatic spike in rabies infections. The research, published today in the open access journal BMC Infectious Diseases, shows that in some provinces of China the number of human rabies cases has jumped dramatically since the new millennium.
Nano vaccine for hepatitis B shows promise for third world
Chronic hepatitis B infects 400 million people worldwide, many of them children. Even with three effective vaccines available, hepatitis B remains a stubborn, unrelenting health problem, especially in Africa and other developing areas. The disease and its complications cause an estimated 1 million deaths globally each year.
Researchers use salmonella to administer vaccines
(PhysOrg.com) -- Researchers at the Biodesign Institute at Arizona State University have made a major step forward in their work to develop a biologically engineered organism that can effectively deliver an antigen in the body. The researchers report that they have been able to use live salmonella bacterium as the containment/delivery method for an antigen.
Researchers: Program discourages HIV transmission in Russia
(Boston)-Researchers from Boston University School of Medicine (BUSM) and Boston Medical Center (BMC) found that sexual behavior counseling during drug addiction treatment should be considered an important component among Russian substance-dependent individuals, in order to decrease risky sexual behavior in the HIV at-risk population. This study appears in the journal Addiction.
From foe to friend: Researchers use salmonella as a way to administer vaccines in the body
Researchers at the Biodesign Institute at Arizona State University have made a major step forward in their work to develop a biologically engineered organism that can effectively deliver an antigen in the body. The researchers report that they have been able to use live salmonella bacterium as the containment/delivery method for an antigen.

News discussion:

Medicine & Health news