Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

OHSU researchers study smallpox vaccination protection over time

11.02.2003


Scientists study those vaccinated more than 60 years ago versus one year ago

Oregon Health & Science University researchers are studying the effectiveness of the smallpox vaccine in patients who received inoculations decades ago compared with those vaccinated more recently. The universal belief has been that smallpox vaccinations provide protection for only three to five years. Until now scientists and physicians assumed that anyone vaccinated more than five years ago had little to no protection left. However, researchers at the OHSU Vaccine and Gene Therapy Institute believe that conventional thinking may not be true. To test their theories, scientists are studying how much protection the smallpox vaccination provides 67 years later versus just a year ago. This information may provide a more accurate way of estimating the spread of a potential smallpox outbreak, because nearly 95 percent of Americans older than 35 were vaccinated, and many may still have strong immunity against smallpox.

"I’ve been intrigued about immunological memory for more than a decade. It’s exciting to be able to apply this interest to something that’s relevant to our community right now," said Mark Slifka, Ph.D., assistant professor of molecular microbiology and immunology in the OHSU School of Medicine "We know that people who contract yellow fever, polio, measles or mumps gain a lifelong immunity to those diseases. Now we want to see if this is universally true for other viruses, such as vaccinia, the virus used for immunizing against smallpox."



Vaccinia is a virus contained within the smallpox vaccine and is closely related to smallpox. However, in most cases, vaccinia does not cause serious health problems. The virus promotes smallpox protection by causing the body to produce protective antibodies and white blood cells that can search for and destroy smallpox-infected cells.

Slifka’s lab is collecting blood samples from study participants. These samples are then analyzed to determine the participants’ level of immunity against smallpox. Of the participants that have joined this ongoing study, six people were vaccinated within the last seven years while more than 100 were vaccinated between 15 and 67 years ago. His team is comparing the immunity of both groups to determine whether the vaccine truly loses potency over time.

This study looks at the effectiveness of both arms of the body’s adaptive immune response: antibodies and T-cells. Blood samples from study participants are exposed to vaccina in petri dishes, the same virus used in the smallpox vaccine. If a person has strong immunity against vaccina, then his/her antibodies will neutralize the virus, thus saving healthy cells from becoming infected. If the virus is able to slip past this first line of defense and actually cause an infection, then a strong T-cell response is necessary to destroy virus-infected cells before they multiply and spread.

"In a petri dish, the vaccinia virus is typically very destructive and will eventually kill all of the cells that it encounters. However, if we mix blood serum of a vaccinated person with the virus before it can invade the first cell, then no damage occurs because the cells are protected against infection. Visually, weak immunity against smallpox looks in the petri dish like a lawn with a lot of dead patches of grass, while strong immunity results in a healthy "lawn" that has very few dead patches. With these and other techniques in hand, we can determine who has strong immunity and who has weak immunity following smallpox vaccination." said Slifka.

Scientists are studying the relationship between two levels of protection: protection against the disease and protection against death. The vaccine may prove to provide less protection against disease over time. In other words, a person might still get infected, but vaccination may still provide enough protection to lower the risk of death.

Another standard, but not proven, belief is that three or more vaccinations provide more immunity. Slifka’s team also will look at the effectiveness of multiple vaccinations to determine if several vaccinations do build stronger immunity. Although most participants in this study have been vaccinated only once or twice, there are several volunteers that have been vaccinated between five and 11 times during their lifetimes.

Another research team at the VGTI and OHSU, led by Janko Nikolich-Zugich, M.D., Ph.D., and Mary Stenzel-Poore, Ph.D., is studying immunity to smallpox and vaccinia in people with weaker immune systems, such as the elderly, those on steroid therapy and those under significant stress. Using mice, they hope to discover specific defects in the immune system that prevent these immunocompromised individuals from receiving safe vaccinations against smallpox. Identifying these defects should help them develop re-engineered versions of the smallpox vaccine that can protect these vulnerable populations from this deadly disease. This group also will use Slifka’s results to complement their research and help engineer new vaccines for the vulnerable populations.

Slifka also hopes to work with his co-investigator, Jon Hanifin, M.D., professor emeritus of dermatology in the OHSU School of Medicine, to develop a future study that will look at the weakened immune systems of people with eczema and other skin conditions who were vaccinated years ago, but by today’s standards shouldn’t have been vaccinated.


SPECIFICS:

Mark Slifka, Ph.D., assistant professor of molecular microbiology and immunology in the OHSU School of Medicine; assistant scientist at the OHSU Vaccine and Gene Therapy Institute and the Oregon National Primate Research Center.

Janko Nikolich-Zugich, M.D., Ph.D., professor of molecular microbiology and immunology in the OHSU School of Medicine; senior scientist at the OHSU Vaccine and Gene Therapy Institute and the Oregon National Primate Research Center.

Mary Stenzel-Poore, Ph.D., associate professor of molecular microbiology and immunology in the OHSU School of Medicine.

Jon Hanifin, M.D., professor emeritus of dermatology in the OHSU School of Medicine

Christine Pashley | EurekAlert!

More articles from Health and Medicine:

nachricht Researchers release the brakes on the immune system
18.10.2017 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht Norovirus evades immune system by hiding out in rare gut cells
12.10.2017 | University of Pennsylvania School of Medicine

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: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>