The world's first intranasal Covid-19 vaccine, developed by Hyderabad-based pharmaceutical firm Bharat Biotech, has been approved for restricted emergency use as heterologous booster doses in adults. The vaccine, called iNCOVACC, can now be administered in people aged 18 years and above as primary doses as well as heterologous booster doses. The latter means that a person can receive a different vaccine from the one that was used for the primary dose series.
The vaccine has received approval for restricted use in emergency situations from the Central Drugs Standard Control Organisation (CDSCO), Bharat Biotech announced on November 28.
All about iNCOVACC
Bharat Biotech's intranasal Covid-19 vaccine is a recombinant replication deficient adenovirus vectored vaccine. This means that critical portions of the genome of SARS-CoV-2 have been removed, such that the viral vector can no longer replicate. The fact that it is a recombinant vaccine means that it has been manufactured using bacterial or yeast cells or parts of a virus to introduce viral proteins into the host. An adenovirus vectored vaccine means that a modified version of an adenovirus has been used which can enter human cells but not replicate inside.
Adenovirus-vectored vaccines are the vaccines in which adenoviruses are used as vectors for delivering a particular antigen into the body of a host, where the cells will read the foreign particle, and create antibodies against it.
The phase I, II and III clinical trials yielded successful results. The vaccine will allow intranasal delivery through nasal drops, a system designed and developed to be cost-effective in low- and middle-income countries.
Bharat Biotech's iNCOVACC has the dual benefit of enabling faster development of variant-specific vaccines and easy nasal delivery. This will allow mass immunisation and protect people from emerging variants of concern, according to the statement. The launch dates, price and availability of the vaccine will be announced soon.
The optimum temperature range for storage and distribution of iNCOVACC is two to eight degrees Celsius.
How does iNCOVACC work?
An intranasal vaccine stimulates a broad immune response by producing a wide range of antibodies including neutralising Immunoglobulin G (IgG) and mucosal Immunoglobulin A (IgA). The vaccine also initiates T cell responses.
According to the official website of Bharat Biotech, immune responses in the nasal mucosa, which is the site of infection, are essential to block the infection and stop the transmission of Covid-19.
When the iNCOVACC vaccine is administered into a person, the immune cells in the body will express the stabilised spike protein. As a result, the body will produce antibodies against the spike protein of SARS-CoV-2.
If a person is naturally exposed to SARS-CoV-2, the immune system will prevent Covid-19 infection in both upper and lower respiratory tracts due to the presence of antibodies. Thus, iNCOVACC has the potential to block SARS-CoV-2 and prevent the transmission of Covid-19.
What Are The Advantages Of iNCOVACC?
Intranasal SARS-CoV-2 vaccines are likely to prevent infection and transmission, and also prevent disease.
According to Bharat Biotech, the advantages of iNCOVACC are that it is non-invasive and needle-free, can be administered easily, is ideally suited for children and adults, and has scalable manufacturing.
The use of this vaccine will eliminate needle-associated risks such as injuries and infections. Also, the nasal mucosa has an organised immune system because of which the nasal route serves as one of the best regions for vaccination.
Where Does iNCOVACC Produce Antibodies?
Since iNCOVACC is an intranasal vaccine, it has the potential to produce local antibodies in the upper respiratory tract, according to the statement. This can potentially reduce infection and transmission of SARS-CoV-2.