Nasal Vaccine Towards COVID-19 Works Effectively In Rodents

Giving vaccines through the nose has advantages over intramuscular injections, especially when it comes to diseases that are transmitted via the respiratory tract. Yet in a rush to save the world from COVID-19, few institutions have focused on intranasal administration and results have lagged far behind. Still, an intranasal vaccine has now proven successful in preclinical studies, opening up the possibility of an alternative approach that could ultimately help rid the world of this scourge.

IScience magazine reports that two doses of an intranasal vaccine developed at Lancaster University provided hamsters with complete protection from lung infections and inflammation from multiple SARS-CoV-2 variants. The same vaccine had previously been shown to be safe and produced an encouraging immune response in mice without testing its level of protection for them.

Existing vaccines produce similar results on these accounts. Where the nose can benefit is in reducing virus shedding from the nose and lungs. This would greatly reduce the likelihood that people who contract COVID-19 would pass it on.

“After we gave the vaccine into the nose of hamsters and then infected them with SARS-CoV-2, we found almost no virus replication in the lungs and nasal lavage of these animals.” said Dr. Muhammad Munir in a statement.

Existing vaccines already provide significant protection for the person being vaccinated because you cannot pass a virus on without becoming infected. Even those who develop a “breakthrough” infection are less likely to transmit the disease than if they hadn’t been vaccinated, but the extent of it is uncertain. The Lancaster studies, conducted in conjunction with the Texas Biomedical Research Institute, raise the possibility that intranasal vaccines may be better at preventing transmission, provided the results can be replicated in humans.

In addition to having the potential to reduce transmission by infected people, intranasal vaccines could overcome vaccination hesitation. A lot of the reasons we’re so close to eliminating polio while other diseases have proven to be more difficult to overcome is because people prefer to take medication orally rather than having a needle stuck in their arm. Spraying a vaccine in your nose might not be as tempting as eating a syruped cube of sugar, but it is a step.

Intranasal vaccines can develop more slowly, but they should be easier to make and distribute because they require less refrigeration. This particular vaccine can be made in eggs, like the annual flu shot. “We are excited about the scalability of this nasal vaccine, which we hope will help reduce vaccine inequality and enable equal access to vaccination around the world. Nasal delivery is also a more attractive route of administration for children, ”said co-author Dr. Lucy Jackson-Jones.

The vaccine uses an engineered Newcastle Disease Virus (NDV) to produce SARS-CoV-2 spike proteins in order to prepare the immune system to recognize the method of cell entry of SARS-CoV-2. NDV is an avian disease whose virus can replicate but, unlike chickens, causes only mild symptoms in humans.

Due to the time-consuming nature of the clinical trials, the intranasal vaccine will not be available until next year at the earliest. Tragically, it is likely that it will then be needed.

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