Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Smallpox pill promising

20.03.2002


New drug could soon thwart smallpox outbreaks


A smallpox pill could help stem an outbreak quickly.
© WHO



An anti-smallpox pill could be on the way if a new compound that shows promise in animal tests proves safe and effective in humans. Such a pill could provide the best method for controlling an unforeseen smallpox outbreak, its developers claim.

The need for new ways to treat smallpox has only become an issue in recent years as the threat of a deliberate release of the virus intensifies. Smallpox - a highly contagious and often lethal viral disease - was officially eradicated by vaccination in 1979.


The new chemical is a modified version of the drug cidofovir, which is used to treat infections in AIDS patients. In 1999 John Huggins of the US Army Medical Research Institute in Fort Detrick, Maryland, and his colleagues found that cidofovir stops mice dying from cowpox1, a relative of smallpox. But cidofovir is expensive and must be injected.

Now Huggins, along with Karl Hostetler of the Veterans Affairs San Diego Healthcare System in California and others, has turned cidofovir into a drug that can be swallowed - by animals at least. "This drug could become the first line of defence," says Hostetler.

The team presented their findings today at the International Conference on Antiviral Research in Prague, Czech Republic.

Fat chance

"We disguised cidofovir so the body thinks it’s a dietary fat," Hostetler explains. His team attached to cidofivir’s active component a molecule called lecithin, a breakdown product of fat found in all foods. This Trojan horse approach tricks the body into absorbing the drug and carrying it to where it is needed.

Small doses of the new compound - called HDP-CDV - killed the virus in smallpox-infected cells. "The big surprise was that its antiviral activity went up 100-fold compared to cidofovir," says Hostetler.

A single, daily dose of the drug also cured mice of cowpox, Huggins found. Untreated mice died within days.

What’s more, cowpox was undetectable in the respiratory tracts of mice treated with HDP-CDV. Because smallpox is spread by infectious droplets that are coughed up, this finding suggests that HDP-CDV might help to stem an epidemic.

These early tests raise hope that HDP-CDV might be incorporated into an anti-smallpox pill that could be distributed widely without the need for public-health workers to administer it, says Hostetler.

"But there is tons of work left to do," he warns. Even though the new compound is based on an existing drug, it must undergo the same rigorous testing as any other. The team don’t expect that process to begin for at least another year.

Outbreak outcry

The possibility of an effective drug for smallpox is likely to fuel the debate among smallpox experts about the best way to control a future outbreak. Many prominent scientists argue that antiviral drugs such as cidofivir shouldn’t play a prominent role.

Antivirals may save lives and perhaps reduce transmission, but they do not confer immunity to the disease, as vaccines do, the argument goes.

Donald Henderson, head of George W. Bush’s newly created Office of Public Health Preparedness, is a prominent sceptic. The use of cidofovir "would be limited to administration at or shortly after infection had occurred to prevent the virus from multiplying and eventually causing disease", he says.

Antiviral drugs would best be used to treat people who can’t be vaccinated, says Henderson. Those with weak immune systems can suffer adverse, even fatal, reactions to smallpox vaccine.

Joseph Esposito, a poxvirus specialist at the US Centers for Disease Control and Prevention in Atlanta, Georgia, agrees: "A new drug would be very important." But in terms of a national strategy, "the first line of defence is a proven one, and that’s vaccination," he says.

But while questions loom about the number of smallpox vaccine doses available to limit an outbreak, and about the possibility of a smallpox virus being engineered that can outwit existing vaccines, antivirals deserve a fair trail, says Hostetler.

References

  1. Bray, M. et al. Cidofovir protects mice against lethal aerosol or intranasal cowpox virus challenge. Journal of Infectious Diseases, 181, 10 - 19, (2000).

TOM CLARKE | © Nature News Service

More articles from Health and Medicine:

nachricht Inselspital: Fewer CT scans needed after cerebral bleeding
20.03.2019 | Universitätsspital Bern

nachricht Building blocks for new medications: the University of Graz is seeking a technology partner
19.03.2019 | Karl-Franzens-Universität Graz

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The taming of the light screw

DESY and MPSD scientists create high-order harmonics from solids with controlled polarization states, taking advantage of both crystal symmetry and attosecond electronic dynamics. The newly demonstrated technique might find intriguing applications in petahertz electronics and for spectroscopic studies of novel quantum materials.

The nonlinear process of high-order harmonic generation (HHG) in gases is one of the cornerstones of attosecond science (an attosecond is a billionth of a...

Im Focus: Magnetic micro-boats

Nano- and microtechnology are promising candidates not only for medical applications such as drug delivery but also for the creation of little robots or flexible integrated sensors. Scientists from the Max Planck Institute for Polymer Research (MPI-P) have created magnetic microparticles, with a newly developed method, that could pave the way for building micro-motors or guiding drugs in the human body to a target, like a tumor. The preparation of such structures as well as their remote-control can be regulated using magnetic fields and therefore can find application in an array of domains.

The magnetic properties of a material control how this material responds to the presence of a magnetic field. Iron oxide is the main component of rust but also...

Im Focus: Self-healing coating made of corn starch makes small scratches disappear through heat

Due to the special arrangement of its molecules, a new coating made of corn starch is able to repair small scratches by itself through heat: The cross-linking via ring-shaped molecules makes the material mobile, so that it compensates for the scratches and these disappear again.

Superficial micro-scratches on the car body or on other high-gloss surfaces are harmless, but annoying. Especially in the luxury segment such surfaces are...

Im Focus: Stellar cartography

The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.

A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...

Im Focus: Heading towards a tsunami of light

Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.

"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Laser processing is a matter for the head – LZH at the Hannover Messe 2019

25.03.2019 | Trade Fair News

A Varied Menu

25.03.2019 | Life Sciences

‘Time Machine’ heralds new era

25.03.2019 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>