Exploding pill that could mean end of vaccine jabs

An EXPLODInG pill that blasts medicine into the cheek from inside the mouth could replace vaccination jabs. The patient simply pushes a soft capsule against the inside of the mouth then squeezes it to cause a chemical reaction inside a tiny chamber in the device. This blasts vaccine out of the pill and through the delicate tissue lining the mouth where it quickly penetrates tiny blood vessels known as capillaries.

The layer of tissue that lines the mouth — the buccal mucosa — has large numbers of capillaries near the surface that can absorb the vaccine rapidly and circulate it round the body, prompting the immune system to produce antibodies that fight infection.

The whole process takes little more than a couple of seconds.

Scientists at the University of California, Berkeley, who came up with the device, called the MucoJet, say it is painless and could mean millions of people are able to immunise themselves against illnesses such as flu or measles without needing to see a doctor for an injection.

It’s estimated that up to 20 per cent of eligible adults refuse to have vaccinations because they are scared of needles.

Meanwhile, the effectiveness of the flu nasal spray vaccine — given to children aged two to seven — has been questioned.

Last year, the Centre for Disease Control and Prevention in the U.S. said there was little or no reduction in flu infections in youngsters given the nasal spray between 2013 and 2016.

One theory is that having been sprayed up the nose, much of the liquid vaccine stays on the surface of the nasal cavity rather than being absorbed fully.

The new pill has been developed as a way to potentially boost absorption and make flu vaccines more effective. The MucoJet capsule — about the size of a large tablet — has an inner compartment that contains two tiny reservoirs.

One is packed with powdered citric acid and sodium bicarbonate, the other contains a powdered protein called ovalbumin (used in studies as a substitute for vaccines). The outer compartment of the pill contains roughly five drops of water. When the patient squeezes it against their cheek, the water dissolves a membrane surrounding the reservoir containing citric acid and sodium bicarbonate, and the chemicals react to produce carbon dioxide gas.

The gas triggers a tiny ‘explosion’ that forces a piston into the reservoir holding the ovalbumin (or vaccine medicine), and propels the contents through the cheek and into the capillaries. The remains of the capsule are discarded.

In animal tests, scientists found seven times more ovalbumin penetrated the cheek using the exploding capsule compared to a dropper that applies it to the surface of the tissue.

The animals’ immune systems also produced three times as many antibodies (infection fighting cells released by the body) when the exploding pill was used, according to findings in the journal Science Translational Medicine.

The more antibodies produced, the better chance the body has of fighting infection.

Scientists hope to have the technology available for widespread use within five years.

John Oxford, professor of virology at Queen Mary University London, said the gas-powered pill was ‘certainly innovative’.

But he warned that vaccinating against flu through the mouth might be less effective than the nose, as flu viruses tend to gather in the nasal cavity.