AZ nasal spray could prove key

ASTRAZENECA could be more effective against Covid-19 – especially the Delta variant – if delivered as a nasal spray rather than as a needle, Australian scientists say.

The CSIRO tested the vaccine as a nasal spray in animals and, in a promising development, found it completely sterilised the virus.

One of the reasons Delta is spreading so quickly is that many people given a needle vaccination against Covid can still catch it and spread it, even though they don’t get seriously ill.

Dr Rob Grenfell, the director of health and biosecurity at the CSIRO, said the organisation’s nasal spray tests in animals stopped the transmission.

“In our animal model it actually led to sterility in the animal, that is there’s no virus detectable by PCR which meant that you’re not infectious, so that was actually a really exciting revelation,” he said.

The problem with using a needle to vaccinate against the virus that causes Covid-19, he said, was that it was a respiratory bug that attached to receptors in nasal cells to enter the body.

“If we were to do this on the nasal cells, we’d be actually creating the immunity, on the surface of the nasal cells,” he said.

Researchers at the Imperial

College in London have already begun trialling an AstraZeneca nasal spray in humans in England but no results are available yet.

Meanwhile Australian researchers are developing multiple nasal sprays that can be used as a complement to vaccination to stop Covid-19 from spreading.

The idea is that everyone would still get a needle vaccination but supplement it with a nasal spray for added protection when they go to mass gatherings, or on aeroplanes.

One group has repurposed the anti-blood clotting drug heparin, which is already approved for human use, into a Covid nasal spray.