Explained: New Nasal Treatment May Block Covid Spread, How It Works And What's The Road Ahead

Researchers have developed an intransal treatment for Covid-19 that decreases the amount of virus that an infected animal releases during breathing.

During exhaling, or coughing or sneezing, virus is released into the air as droplets. The process is called "viral shedding". When someone close to the infected person comes in contact with these viral particles being shed, they are at risk of getting infected.

Therefore, as this treatment reduces the virus being shed, it also reduces the scope of transmission as well.

Here we explain how this treatment works, what are the research findings, and what's the road ahead for this treatment.

What we know of this treatment?

The United States-based Gladstone Institutes had previously developed a single-dose intranasal treatment that protects against severe SARS-CoV-2, the virus that causes Covid-19 disease.

"In a new study published in Proceedings of the National Academy of Sciences, they show that this new treatment, called a therapeutic interfering particle (TIP), also decreases the amount of virus shed from infected animals and limits transmission of the virus," said Gladstone Institutes in a press release.

TIPs are a preparation that prevents the virus from replicating itself. Simply speaking, TIPs prevent virus growth in infected cells.

Since nose is often the first place in the body to be exposed to coronavirus, and also the main medium of transmission, TIPs targeting nasal cells would limit the viral particles growth there.

"To our knowledge, this is the only single-dose antiviral that reduces not only symptoms and severity of Covid-19, but also shedding of the virus," said Sonali Chaturvedi, a research investigator at Gladstone and first author of the paper.

Less viral shedding would mean that people around the infected person have less chances of being infected.

What are the research findings?

The research was carried out on hamsters infected with SARS-CoV-2, the virus that causes Covid-19.

One group of hamsters was given the TIP treatment and the other group —called the control group— was not givem the treatment.

"Compared to hamsters that hadn't received the TIPs, treated animals had less virus in their nasal passages at every time point. By day five, all control animals were still shedding high levels of virus, while the virus was undetectable in four out of five TIP-treated animals," said the Gladstone Institutes.

Since virus shedding is directly related to how infectious someone is, the findings suggest that the treatment reduces the transmission.

"If viral shedding can be reduced, the number of secondary contacts likely to become infected will also very likely be reduced, which will in turn decrease overall virus dissemination and help keep vulnerable individuals safe," said Gladstone Senior Investigator Leor Weinberger, senior author of the new paper.

However, the research also shows that while viral shedding is reduced and chances of transmission are reduced, it's not completely ruled out. When infected hamsters treated with TIPs mixed with un-infected hamsters, there was some spread but symptoms were milder.

The press release stated, "When the SARS-CoV-2–infected animals were housed in cages with uninfected animals, treatment of the infected animals with TIPs did not fully prevent the transmission of COVID-19. However, it did lead to significantly lower viral loads and milder symptoms of infection in the newly exposed animals."

The road ahead for the treatment

While the findings appear to be promising, one needs to note that it's still in animal trials stage.

The Gladstone Institutes is seeking US Food and Drug Administration (FDA) approval for human trials of the treatment. But since the approval is yet to come, it'st still some time that this treatment hits the market as human trial can take up to years.

The US FDA human trials are usually structured in four phases:

Phase 1 involves 20-100 healthy volunteers or people with the disease or a condition and it usually lasts for several months. The purpose is to test the safety and dosage of the drug.

Phase 2 involves hundreds of people with the disease or condition and it can last up to two years. The purpose is to test the efficacy and side effects of the drug.

Phase 3 involves 300-3,000 volunteers who have the disease or condition and it can last anywhere between one to four years. The purpose is to test the efficacy and to monitor any adverse reactions of the drug.

Phase 4 involves several thousand volunteers who have the diseas or condition and the purpose is to check the safety and efficacy of the drug.

How the treatment is different from current treatments

Most of existing treatment for Covid-19 is symptomatic, which means that it treats a person's treatment rather than targeting the virus inside.

Covid-19 can cause many symptoms, with fever, cough, and runny nose being some of the most common symptoms. Current treatment regimes treat these individual symptoms and allow the immune system to clear the virus inside.

TIPs, on the contrary, target the virus itself, preventing its replication and reducing the viral shedding. This in turn prevents transmission.

It's also important to note that this treatment is not a vaccine. It does not train a person's immune system. It's a treatment option.