A nasal spray vaccine for COVID-19 had been anticipated by researchers all around the world because this would allow vaccine delivery directly in the airway, which has been the initial sight of entry for the virus. In addition to this, a nasal spray vaccine can also decrease the likelihood of contracting an infection and provide a painless alternative to the vaccine shot.
There are already companies around the world that have successfully produced nasal Covid vaccines. For example, just this past month, Bharat Biotech’s COVID-19 nasal spray vaccine was approved by the Indian Health Minister. CanSino Biologics Inc in China was also granted emergency approval for its inhaled version of the COVID vaccine by the regulatory board in China. Although the trial results for the Indian vaccine are not published as of yet, CanSino has shared that its vaccine, which is delivered via a nebulizer machine, can help create a strong immune system defense against infection.
Amidst these developments, the scientific community in the UK was greatly optimistic about the outcomes of the partnership between AstraZeneca and Oxford University to come up with their own nasal spray vaccine for COVID. The company was one of the few in the country exploring such avenues.
The study was conducted by researchers at Oxford University and financed by AstraZeneca, it enrolled 30 participants who had not been vaccinated prior to the study and 12 volunteers who had received the standard two-dose vaccination through injections. The study spanned the course of around a year and started somewhere in mid-2021 and ended just this month.
It concluded that the immune response developed by the nasal vaccine in the blood was weaker than that of a shot and very few participants in the trial actually developed antibodies in their respiratory mucous membranes. The findings of the study were published in an open-access journal called eBioMedicine by The Lancet and it was also shared, that despite the initially underwhelming results, it is important to acknowledge that no safety concerns or unpleasant events were reported during the trial. This is also only the first phase of a usually 3 phase study, so improved results in the future can be expected.
“The results of the trial were not what we had hoped for,” said chief investigator of the study Sandy Douglas, “But this does not mean that delivering the vaccine through the nose and lungs is not the right approach.”
Douglas has also highlighted the need for more research to come up with safer delivery routes for nasal medicines that are also practical to thwart the transmission of the respiratory pandemic. Andrew Freedman, a reader of infectious disease at Cardiff University has also acknowledged the trial results as disappointing but stressed that this failure should not deter researchers from making efforts in the future.
Despite its failure, in this case, Astra has been able to produce a flu vaccine in nasal spray form called Flumist that has successfully acted as an alternative to needles. This however did not stop the company shares from falling by up to 1% in London.