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Last Updated : Sep 24, 2020 02:52 PM IST | Source: Moneycontrol.com

COVID-19: Why nasally administered vaccine experiments are gaining ground among drug makers

Serum Institute’s decision to manufacture Codagenix's intranasal vaccine is the latest example. An intranasal vaccine is simple can even be self-administered. Also, the vaccines being developed by Serum and Bharat Biotech require only a single dose.

Representative image
Representative image

Pune-based Serum Institute of India announced early this week that it will manufacture US-based Codagenix's intranasal live-attenuated (weakened) COVID-19 vaccine candidate.

Serum had received regulatory approval from the Review Committee on Genetic Manipulation (RCGM) of the Department of Biotechnology (DBT).

Serum will supply the vaccine for large-scale safety and efficacy studies even as it prepares to meet global vaccine supply requirements.


The pre-clinical testing of a single, intranasal dose of the vaccine, called CDX-005, in animals has yielded encouraging safety and efficacy signals, Codagenix and Serum said in a joint statement.

COVID-19 Vaccine

Frequently Asked Questions

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How does a vaccine work?

A vaccine works by mimicking a natural infection. A vaccine not only induces immune response to protect people from any future COVID-19 infection, but also helps quickly build herd immunity to put an end to the pandemic. Herd immunity occurs when a sufficient percentage of a population becomes immune to a disease, making the spread of disease from person to person unlikely. The good news is that SARS-CoV-2 virus has been fairly stable, which increases the viability of a vaccine.

How many types of vaccines are there?

There are broadly four types of vaccine — one, a vaccine based on the whole virus (this could be either inactivated, or an attenuated [weakened] virus vaccine); two, a non-replicating viral vector vaccine that uses a benign virus as vector that carries the antigen of SARS-CoV; three, nucleic-acid vaccines that have genetic material like DNA and RNA of antigens like spike protein given to a person, helping human cells decode genetic material and produce the vaccine; and four, protein subunit vaccine wherein the recombinant proteins of SARS-COV-2 along with an adjuvant (booster) is given as a vaccine.

What does it take to develop a vaccine of this kind?

Vaccine development is a long, complex process. Unlike drugs that are given to people with a diseased, vaccines are given to healthy people and also vulnerable sections such as children, pregnant women and the elderly. So rigorous tests are compulsory. History says that the fastest time it took to develop a vaccine is five years, but it usually takes double or sometimes triple that time.

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Plans are under way to begin human testing or Phase I trial in the UK before the end of 2020.

Serum has company

Another Indian vaccine maker, Bharat Biotech, on Wednesday announced that it had entered into a licensing agreement with Washington University School of Medicine in St Louis for a novel chimpanzee-adenovirus, single dose intranasal vaccine for COVID-19.

While the Phase I trials will take place in St Louis University’s Vaccine & Treatment Evaluation Unit, Bharat Biotech, upon obtaining regulatory approval, will pursue further stages of clinical trials in India, and undertake large-scale manufacture of the vaccine at its GMP facility in Genome Valley, Hyderabad.

Interestingly, the intranasal vaccine of both Serum and Bharat Biotech requires only a single dose, compared to two doses other vaccines might need.

What is intranasal vaccine?

Intranasal vaccine is administered through nose, in contrast to most vaccines that are given as injections, with the exception of polio vaccine, which is delivered orally.

AstraZeneca’s FluMist is the only nasal spray vaccine against H1N1 Influenza or a flu that’s approved in the US, Canada and Europe so far. FluMist vaccine contains four different variants of weakened or live- attenuated flu viruses.

Is intranasal vaccine effective?

Many viruses, including Coronavirus, infect through mucosa, the moist tissue found in the nose, mouth, lungs and digestive tracts. Unlike other COVID-19 vaccines in development, intranasal vaccine is delivered at the infection site , i.e., the nose and lungs to stop infection.

Researchers in Washington University School of Medicine, who developed the vaccine, in their animal studies on mice, compared the intranasal vaccine to vaccine given through intramuscular injection.

They found that while the injection induced an immune response that prevented pneumonia, it did not prevent infection in the nose and lungs. In contrast, the nasal delivery route prevented infection in both the upper and lower respiratory tracts — the nose and lungs — suggesting that vaccinated individuals would not spread the virus or develop infections elsewhere in the body.

The study was published in Cell, the peer-reviewed scientific journal. The researchers said that they will test the vaccine on non-human primates or monkeys for efficacy.

Why companies are focusing on intranasal vaccine?

There are plenty of advantages. An intranasal vaccine is simple and efficient to administer. It doesn't require the use of medical consumables such as needles and syringes, thus significantly lowering the overall cost of a vaccination drive. It is also convenient for self-administration.

What do experts say?

Experts like Dr Gagandeep Kang have a word of caution on nasal vaccines.

“Approved Influenza vaccines can be given by injection or nasally. Usually, mucosally delivered vaccines will have somewhat lower immune response," Dr Kang told Moneycontrol.

Kang is the country's leading expert on vaccines and Professor at the Department of Gastrointestinal Sciences at Christian Medical College, Vellore.

Another expert at a vaccine company, who didn't want to be named, said the intranasal flu vaccines may have better safety profile and are found to be more effective in children compared to adults.

“More studies are needed to determine how well the intranasal route works on adults," he said. “At the moment, nasal vaccines are still in the early stages of development. We can't expect the vaccine to hit the market by the second half of FY21," the executive said.
First Published on Sep 24, 2020 02:52 pm