Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


New findings about protection against pneumococcal disease


Findings hoped to spur the development of an improved vaccine

Since 2000, U.S. infants have been routinely immunized against pneumococcal (Streptococcus pneumoniae) infection. Now, Boston researchers have made a surprising discovery about natural immunity to pneumococcus. Two related studies, led by Dr. Richard Malley of the Children’s Hospital Boston Division of Infectious Diseases and Dr. Marc Lipsitch of the Harvard School of Public Health, suggest that natural protection from pneumococcal disease may derive from some previously unrecognized immune mechanism, which could possibly be exploited for a new vaccine. The latest study appears in the current (March 29) issue of the Proceedings of the National Academy of Sciences.

In the U.S., before the advent of the pneumococcal conjugate vaccine, known as Prevnar, S. pneumoniae caused more than 7 million ear infections each year, half a million episodes of bacterial pneumonia, and life-threatening cases of meningitis and bacteremia. Prevnar is made up of material from the outer capsule of each of the seven pneumococcal strains most common in the U.S. This material triggers recipients’ immune systems to produce so-called anticapsular antibodies specific to those strains. However, Prevnar doesn’t work against many pneumococcal strains in the developing world, where pneumococcus kills nearly 1 million children annually, and it is expensive and difficult to manufacture, leading to chronic shortages. Moreover, in several studies, use of pneumococcal conjugate vaccines caused non-vaccine strains to become more common, raising concerns that Prevnar could eventually become ineffective even in the U.S. Of 90 known pneumococcal strains, Prevnar only covers seven.

Lipsitch and Malley first conducted epidemiologic studies in unvaccinated toddlers in the U.S., Israel, and Finland. As they reported in January in the online journal PLoS Medicine, the incidence of invasive disease from almost all pneumococcal strains fell by nearly half between 1 and 2 years of age. Yet, anti-capsular antibody concentrations increased only slightly, suggesting that a mechanism other than antibody to the pathogen’s outer capsule may be conferring natural protection against pneumococcal disease.

What then might provide this protection? Looking at the first step of pneumococcal disease, colonization of the nose and throat, Malley and Lipsitch were able to elicit long-lasting immunity to pneumococcus in mice independently of any antibodies. In the current (March 29) Proceedings of the National Academy of Science, they report that when mice were exposed to live pneumococci, or to a whole-cell vaccine developed in Malley’s lab, they were highly immune to pneumococcal colonization -- even if they were genetically unable to make antibodies. Moreover, mice exposed to a single pneumococcal strain became immune not just to that strain, but to others. The immunity appeared to arise from an effect on the immune system’s CD4+ T-cells, since mice that lacked these cells did not develop immunity.

"Textbooks say that naturally-acquired protection against pneumococcal disease depends on the development of antibody against the capsule of the bacterium," says Malley, who is also an assistant professor in pediatrics at Harvard Medical School. "We were surprised to find that protection was independent of not only antibody to the capsule, but also antibody of any specificity."

Overall, their findings suggest that while antibodies are sufficient for protection against pneumococcal disease, they may not represent the natural mechanism of protection.

"An interesting observation is that HIV-infected children, whose CD4+ cells are depleted by the virus, are at about a 200-fold higher risk for pneumococcal disease," Malley adds. "Our experiments in mice may provide an explanation for that vulnerability."

The whole-cell vaccine developed by Malley’s lab could potentially protect against all pneumococcal strains, Malley says. The vaccine, made of killed pneumococcal cells, was shown to prevent colonization and invasive disease when given to animals in the form of nose drops. Malley believes the vaccine stimulates CD4+ T-cells to identify components of pneumococcus that are identical in every strain and to provide protection at the earliest stage of infection, when pneumococcus is colonizing the nasal passages.

The whole-cell vaccine, or a derivative of it, would be a boon for the developing world, because it is inexpensive, covers all pneumococcal strains, and does not require refrigeration. Malley and colleagues are now working to define precisely how the whole-cell vaccine works immunologically, and determine what parts of the killed bacterium provide the actual protection. The ultimate goal is to test the vaccine in adult volunteers, and eventually in children.

Susan Craig | EurekAlert!
Further information:

More articles from Health and Medicine:

nachricht New potential cancer treatment using microwaves to target deep tumors
12.10.2016 | University of Texas at Arlington

nachricht Breakthrough in Mapping Nicotine Addiction Could Help Researchers Improve Treatment
04.10.2016 | UT Southwestern Medical Center

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: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Innovative technique for shaping light could solve bandwidth crunch

20.10.2016 | Physics and Astronomy

Finding the lightest superdeformed triaxial atomic nucleus

20.10.2016 | Physics and Astronomy

NASA's MAVEN mission observes ups and downs of water escape from Mars

20.10.2016 | Physics and Astronomy

More VideoLinks >>>