Covid-19 vaccine: Suction delivery technique similar to cupping tested in rats

Studies in rats suggest a device that applies suction to the skin may make cells take up more vaccine particles and enhance the immune response

By Clare Wilson

A device that creates suction against the skin, in a similar manner to the alternative medicine technique of cupping, is being investigated as a new type of covid-19 vaccine delivery method.

The suction device is being used in human trials of a DNA-based experimental vaccine against the coronavirus. Work in rats has now found that the approach enhances the immune response.

Cupping uses heated cups placed on the skin to create a partial vacuum next to the body as the air inside the cups cools down. It is used in several types of alternative therapies, such as traditional Chinese medicine, for purposes such as reducing pain and inflammation, although there is no good evidence that it works.

When it comes to vaccines, however, suction against the skin seems to make cells of the dermis take up more vaccine particles.

The suction device is being used in trials of a covid-19 vaccine made by South Korean biotech firm GeneOne Life Science. The vaccine is based on a small circle of DNA called a plasmid, which encodes the coronavirus spike protein.

First, the vaccine is injected into the skin of the arm as normal. Then, the suction machine, which has a 6-millimetre orifice, is applied at the injection site for 30 seconds. It isn’t painful and leaves no mark, says Hao Lin at Rutgers University in New Jersey, who has tried the device on himself.

Studies on rats, published today, show that using the suction boosted the amount of antibodies made by the animals 100-fold.

This may happen because stretching and then relaxing the skin cells encourages their cell membranes to to pull inwards, taking in particles that were previously outside of the cell, says Lin.

The technique could help advance the wider fields of DNA vaccines and DNA-based gene therapies. DNA plasmids are stable at room temperature for a year, but have previously been held back by the difficulty of getting enough DNA inside cells, says Lin. “The real hope is that [the delivery method] is a very cheap and easy process that can be done in the developing world,” says team member Jonathan Singer, also at Rutgers University.

Journal reference: Science Advances, DOI: 10.1126/sciadv.abj0611