Intranasal Vaccine

Developer:

• Indian Immunologicals Ltd (IIL) in collaboration with Griffith University

Target:

• SARS-CoV-2

Administration:

• Intranasal (via nasal pathways)

Features of Intranasal Vaccines

1.     Non-invasive & Needle-free:

o   Does not require needles, reducing the risk of needle-associated injuries and infections.

2.     Ease of Administration:

o   Can be administered without the need for trained healthcare workers.

3.     High Compliance:

o   User-friendly and generally more acceptable to the public.

4.     Scalable Manufacturing:

o   Capable of being produced on a large scale to meet global demand.

5.     Mucosal Immunity:

o   Prevents the virus from establishing infection at the entry point (nasal passages).

o   Stimulates a broad immune response, including:

§  Neutralizing IgG

§  Mucosal IgA

§  T cell responses

6.     Localized Immunization:

o   Immune response is localized at the infection site (nasal mucosa), helping to block infection and transmission of COVID-19.

7.     Immunity Duration:

o   Potential to offer protection for up to a year with just one dose.

IIL’s Live-Attenuated Booster Vaccine

Technology Used:

• Codon deoptimization technology

Codon Deoptimization Technology:

• Involves modifying the virus to mimic a natural infection without causing harm.
• Process: Decreases the frequency of underrepresented codon pairs (genetic determinants for amino acids) without altering the amino acid sequences.
• Advantages:
• Efficient virus attenuation strategy.
• The degree of attenuation can be regulated as needed.
• Extremely safe and takes less time than traditional methods, which typically take several years.

MCQs

1. Consider the following statements regarding intranasal vaccines:

1.     Intranasal vaccines are non-invasive and do not require trained healthcare workers for administration.

2.     They primarily stimulate systemic immune responses, which are effective throughout the body.

3.     Codon deoptimization technology used in some intranasal vaccines alters the amino acid sequences to enhance immune response.

Which of the statements given above is/are correct?

a) 1 only
b) 1 and 2 only
c) 2 and 3 only
d) 1, 2, and 3

2. Which of the following is a key feature of mucosal immunity induced by intranasal vaccines?

a) It targets the entire respiratory system, providing full-body immunity.
b) It stimulates only T cell responses, leaving other immune responses unaffected.
c) It prevents the virus from establishing infection at the entry point in the nasal passages.
d) It requires multiple doses to maintain long-term immunity.

3. Which of the following best describes the principle behind codon deoptimization technology used in live-attenuated vaccines?

a) Increasing the mutation rate of the virus to weaken its pathogenicity.
b) Altering the virus's genome to increase the production of harmful proteins.
c) Modifying the virus to mimic a natural infection without changing amino acid sequences.
d) Enhancing the frequency of dominant codon pairs to boost viral replication.

4. Why is the intranasal vaccine considered advantageous in a global vaccination effort against pandemics like COVID-19?

a) It can be easily administered without healthcare workers, making it scalable.
b) It stimulates immunity only in the upper respiratory tract, avoiding systemic side effects.
c) It requires a complex manufacturing process, ensuring higher efficacy.
d) It provides lifelong immunity with just a single dose.

5. Which of the following correctly explains why live-attenuated vaccines using codon deoptimization technology are safer and faster to develop?

a) They involve years of research and development to weaken the virus gradually.
b) They modify the virus to replicate rapidly, overwhelming the immune system.
c) They decrease the frequency of underrepresented codon pairs, allowing regulated attenuation.
d) They alter the amino acid sequences to eliminate all viral proteins.

Answers:

1.     a) 1 only

2.     c) It prevents the virus from establishing infection at the entry point in the nasal passages.

3.     c) Modifying the virus to mimic a natural infection without changing amino acid sequences.

4.     a) It can be easily administered without healthcare workers, making it scalable.

5.     c) They decrease the frequency of underrepresented codon pairs, allowing regulated attenuation.