Needle-free, heat-stable vaccine for developing nations

Vaccines have a delivery problem when it comes to developing nations. It can be technically challenging and expensive in large part because vaccines need to be stored in refrigerators or freezers. A so-called "cold chain" cannot be broken until vaccines are administered. Lack of refrigeration combined with the lack of trained personnel, make it impossible for many to be vaccinated against standard infections, such as tetanus, rotavirus, diphtheria, pertussis (whooping cough) and other diseases. So, a number of companies have been working on better ways of vaccine "delivery," in two senses of the word--actual delivery of the drug from factory to patient, and then a method of delivering the vaccine into the body that does not require a great deal of training.

A group of researchers think they have found a solution to both delivery problems: Nasal drops. A vaccine delivered as nasal drops effectively induced an immune response in mice and protected them from rotavirus infection, according to a study published in the November issue of Clinical and Vaccine Immunology. The new vaccine delivery system has also been tested successfully and found to be heat stable with tetanus and is currently being tested with diphtheria and pertussis.

A team from the Cummings School of Veterinary Medicine at Tufts University and Tufts University School of Medicine collaborated with researchers from Boston and Tulane Universities developed tested the effectiveness of immunization with harmless bacteria that were engineered to display rotavirus protein.

"The vaccine with the Bacillus bacteria is very inexpensive to produce in large quantities and, unlike most traditional vaccines, requires no special purification steps before use. As a result, the cost of vaccine production is unusually low," said researcher Saul Tzipori, in a prepared statement.

The researchers also said that the vaccine would not need to be refrigerated and the needle-free approach to vaccination works best in developing countries where clean needles and syringes and trained personnel are not always available.

- read the Tufts release
- see the abstract