No-refrigeration, spray vaccine could curb diseases in remote areas

March 19, 2014, American Chemical Society

A new kind of single-dose vaccine that comes in a nasal spray and doesn't require refrigeration could dramatically alter the public health landscape—get more people vaccinated around the world and address the looming threats of emerging and re-emerging diseases. Researchers presented the latest design and testing of these "nanovaccines" at the 247th National Meeting & Exposition of the American Chemical Society (ACS), the world's largest scientific society.

Their talk was one of more than 10,000 presentations at the meeting, being held here through Thursday at the Dallas Convention Center and area hotels.

"Our nanovaccine approach could be instrumental for containing future outbreaks of recently emerged and re-emerging diseases, such as SARS, new flu strains and multi-drug resistant tuberculosis," said Balaji Narasimhan, Ph.D., the project's lead researcher.

He noted that most of today's vaccines require needles, boosters and refrigeration, all of which pose challenges for doctors and patients. Other than the pain factor, which can lower the chances that someone will seek out a vaccine, follow-up shots and refrigeration further reduce the reach of these vitally important preventive treatments. In some places with limited resources, simply isn't available. Thus, many people who need vaccinations the most aren't getting them at all. The good news is that the vaccines Narasimhan's team is developing don't need to be kept cold and are easy to administer.

"Our nanovaccines can be stored at room temperature for as long as six to 10 months and still work," said Narasimhan, professor of chemical engineering at Iowa State University. "Also, we're designing them so they get delivered in one dose through a , which could potentially allow patients to give the to themselves."

Another major limitation of traditional vaccines is the way they work, he said. Most current vaccines help a person develop immunity by introducing part of a virus or bacteria and triggering the body's humoral response—the part of the that produces antibodies to fight off a harmful pathogen. Later, if the person gets infected by that microbe, the body immediately knows how to respond.

But increasingly, evidence is emerging that the other component of the body's immune system, what's called the cell-mediated arm, also plays an important part in some emerging and re-emerging diseases, such as whooping cough. This side of the immune system depends on a group of cells called T cells, rather than antibodies, to fight viruses and bacteria.

Part of the elegance of these nanovaccines is their simplicity and versatility, Narasimhan explained. They are made of only two components: bits of proteins from a virus or bacteria packed into nontoxic, biodegradable polymers that can be custom-designed.

When administered through the nose or by a shot, these tiny packages enter the body and flag the immune system. Sentinels called antigen-presenting cells that keep watch in the body for foreign invaders gobble up the nanovaccine particles, chop up the polymers and pathogen proteins, and appropriately put pieces of the proteins on their surfaces. Depending on the chemistry of the nanovaccine, this triggers the body's cell-mediated or humoral immune response and trains it to recognize the pathogen and attack it quickly in case of future infections.

"We have exciting results that attest to the ability of the nanovaccine formulations to do a very good job of activating cell-mediated immunity," said Narasimhan. "We've shown that it works with rodents, and we're moving forward to show that in larger animals, as well."

Explore further: Protein serves as a natural boost for immune system fight against tumors

More information: Presentation: Pathogen mimicking nanovaccine platform technology: A new paradigm

The design of vaccines and therapeutics to address infectious diseases is fraught with challenges ranging from the need for cold storage to poor immunogenicity to the need for multiple doses to the need for needle-based methods that require medical professionals to administer. We have developed a cross-disciplinary approach at the intersection of polymer chemistry, nanotechnology, and immunology for the molecular design of a safe, needle-free, and efficacious nanoparticle-based platform that can address these challenges and provide a robust technology to address both pre- and post-exposure to respiratory pathogens. These biodegradable nanoparticles are based on amphiphilic polyanhydrides, which degrade by hydrolytic cleavage of the anhydride bond. We have shown using a bottom-up approach that vaccine adjuvants based on amphiphilic polyanhydride nanoparticles are capable of mimicking a natural infection and inducing a robust immune response with long-lived protection against a subsequent challenge. The nanoparticles possess the unique ability to mimic pathogens with respect to persisting within and activating immune cells as well as rapidly distributing to tissue sites distal to the site of administration. Furthermore, these particles can be targeted for uptake by immune cells by functionalizing their surface with carbohydrates, enabling more efficient delivery of antigen to dendritic cells and macrophages.
Our studies have shown that the nanoparticles are safe when administered via multiple routes – intranasal, subcutaneous, and intramuscular. These particles are stable at high temperature for extended periods of time obviating the "cold chain", which is a major hurdle in the deployment of vaccines to remote regions of the globe. The nanoparticles can be designed to encapsulate fragile protein antigens and deliver them in a sustained manner to immune cells, facilitating the maintenance of antigen-specific CD8+ and CD4+ T cells. We have demonstrated that these nanovaccines confer full protection in a single intranasal dose ten months prior to lethal challenge by several respiratory pathogens. Additionally, these particles can be used for effective intracellular delivery of antibiotics in a single administration, which results in lower toxicity, enhanced patient compliance, dose sparing, and cost savings. This rational approach for designing novel amphiphilic materials as nanoscale adjuvants and therapeutics has the tantalizing potential to catalyze the development of next generation technologies against emerging and re-emerging diseases.

Related Stories

Protein serves as a natural boost for immune system fight against tumors

January 30, 2014
Substances called adjuvants that enhance the body's immune response are critical to getting the most out of vaccines. These boosters stimulate the regular production of antibodies—caused by foreign substances in the body—toxins, ...

The rocky road to a better flu vaccine

January 23, 2014
Currently approved flu vaccines are less effective in the elderly, yet an estimated 90% of influenza-related deaths occur in people over 65. A paper published on January 23rd in PLOS Pathogens reports on the challenges scientists ...

Explainer: What is the immune system?

January 8, 2014
The immune system is an integral part of our body, keeping us safe from diseases – from the common cold to more severe illnesses such as cancer.

Bacteria may assist the immune system response against cancer

March 3, 2014
(Medical Xpress)—Recent research from the University of Otago shows that bacteria may assist the body's immune system response against cancer cells and help fight tumours like melanoma.

Unique individual demonstrates desired immune response to HIV virus

March 10, 2014
One person's unique ability to fight HIV has provided key insights into an immune response that researchers now hope to trigger with a vaccine, according to findings reported by a team that includes Duke Medicine scientists.

Recommended for you

In most surgery patients, length of opioid prescription, number of refills spell highest risk for misuse

January 17, 2018
The possible link between physicians' opioid prescription patterns and subsequent abuse has occupied the attention of a nation in the throes of an opioid crisis looking for ways to stem what experts have dubbed an epidemic. ...

Patients receive most opioids at the doctor's office, not the ER

January 16, 2018
Around the country, state legislatures and hospitals have tightened emergency room prescribing guidelines for opioids to curb the addiction epidemic, but a new USC study shows that approach diverts attention from the main ...

FDA bans use of opioid-containing cough meds by kids

January 12, 2018
(HealthDay)—Trying to put a dent in the ongoing opioid addiction crisis, the U.S. Food and Drug Administration on Thursday slapped strict new restrictions on the use of opioid-containing cold and cough products by kids.

Taking ibuprofen for long periods found to alter human testicular physiology

January 9, 2018
A team of researchers from Denmark and France has found that taking regular doses of the pain reliever ibuprofen over a long period of time can lead to a disorder in men called compensated hypogonadism. In their paper published ...

Nearly one-third of Canadians have used opioids: study

January 9, 2018
Nearly one in three Canadians (29 percent) have used "some form of opioids" in the past five years, according to data released Tuesday as widespread fentanyl overdoses continue to kill.

Growing opioid epidemic forcing more children into foster care

January 8, 2018
The opioid epidemic has become so severe it's considered a national public health emergency. Addiction to prescription painkillers, such as oxycodone and morphine, has contributed to a dramatic rise in overdose deaths and ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.