Shipping vaccines in an unbroken temperature-controlled supply chain (a "cold chain") all the way to recipients is a major logistical and financial challenge in remote areas and developing countries. According to Doctors Without Borders, the need to keep vaccines within a temperature range of 2-8°C is one of the main factors behind low immunization-coverage rates.
Researchers have come up with three simple and inexpensive vaccine additives to get around this obstacle. Using minute quantities of nanoparticles, or FDA-approved polymer (polyethylene glycol), or higher amounts of sucrose, they were able to stabilize vaccines at room temperature for several weeks or, in some cases, months. Their approach, which was successfully tested on a vaccine for rodents, is published in Nature Communications.
The study addressed viral-vector vaccines, the most common type of vaccine, which normally only last for a few days at room temperature. At that point, the viral components of the vaccines lose their structural integrity. The scientists' approach, which consists of stabilizing the vaccines against such fluctuations through simple biocompatible additives, has delivered excellent results.
In their first approach, osmotic pressure is applied on the inactivated viruses (the main component of the vaccine) using a cloud of negatively charged nanoparticles. The virus is already subject to an outward osmotic pressure due to its genetic material (RNA or DNA), which has a high negative charge and is held inside the virus. The nanoparticles form a cloud of negatively charged objects that cannot enter the virus, thus generating counter-osmotic pressure that keeps the virus intact. "With this method, infectivity for a virus reached a half-life of 20 days," says the author.
The second approach consists in stiffening the virus's capsid, which envelops the inactivated virus, by adding polymers. This additive mainly stabilizes the virus by slowing its oscillations by changing the stiffness of the capsid. As a result, the vaccine remained fully intact for 20 days with an estimated half-life of ~70 days.
Finally, adding sucrose, a common sugar, to the vaccine makes the environment more viscous and slows down fluctuations. "It's a little like adding honey, where all motion is slowed down," says the author. With this third approach, 85% of the vaccine's properties were intact after 70 days.
Using these results, the researchers applied their methods to a vaccine that is currently in development. They were able to stabilize a vaccine against Chikungunya, a tropical virus, for 10 days, and then successfully inoculated mice with it. "The next step will be to run more extensive tests on specific vaccines, possibly combining the three different approaches."
This study could really impact the effort to increase immunization coverage. Currently, in areas where electricity and refrigeration are limited, vaccines are moved from one refrigerated space to the next and then delivered to recipients in coolers. This complicated process accounts for nearly 80% of the cost of vaccination programs. And that, up until now, has been a significant impediment.
http://actu.epfl.ch/news/a-method-for-storing-vaccines-at-room-temperature/
A method for storing vaccines at room temperature
- 1,159 views
- Added
Edited
Latest News
Abusive drugs hijack natura…
By newseditor
Posted 23 Apr
Mechanism of action of the…
By newseditor
Posted 23 Apr
Role of fat in rare neurolo…
By newseditor
Posted 23 Apr
How protein synthesis in de…
By newseditor
Posted 22 Apr
Atlas of mRNA variants in d…
By newseditor
Posted 22 Apr
Other Top Stories
Artificial Intelligence to detect infectious bacterial on the skin
Read more
Artificial intelligence system learns to diagnose, classify intracr…
Read more
New, rapid and robust method for single cell chromatin accessibilit…
Read more
World's smallest tic-tac-toe game board designed with DNA
Read more
Brain-inspired computer vision
Read more
Protocols
A programmable targeted pro…
By newseditor
Posted 23 Apr
MemPrep, a new technology f…
By newseditor
Posted 08 Apr
A tangible method to assess…
By newseditor
Posted 08 Apr
Stem cell-derived vessels-o…
By newseditor
Posted 06 Apr
Single-cell biclustering fo…
By newseditor
Posted 01 Apr
Publications
Exploiting pancreatic cance…
By newseditor
Posted 23 Apr
Structure of antiviral drug…
By newseditor
Posted 23 Apr
Type-I-interferon-responsiv…
By newseditor
Posted 23 Apr
Selenium, diabetes, and the…
By newseditor
Posted 23 Apr
Long-term neuropsychologica…
By newseditor
Posted 23 Apr
Presentations
Hydrogels in Drug Delivery
By newseditor
Posted 12 Apr
Lipids
By newseditor
Posted 31 Dec
Cell biology of carbohydrat…
By newseditor
Posted 29 Nov
RNA interference (RNAi)
By newseditor
Posted 23 Oct
RNA structure and functions
By newseditor
Posted 19 Oct
Posters
A chemical biology/modular…
By newseditor
Posted 22 Aug
Single-molecule covalent ma…
By newseditor
Posted 04 Jul
ASCO-2020-HEALTH SERVICES R…
By newseditor
Posted 23 Mar
ASCO-2020-HEAD AND NECK CANCER
By newseditor
Posted 23 Mar
ASCO-2020-GENITOURINARY CAN…
By newseditor
Posted 23 Mar