m-RNA Covid vaccine in India
Introduction-
India’s first homegrown mRNA Covid-19 vaccine, GEMCOVAC-19, has got “restricted emergency use” approval for the 18 and above age group. One of the unique features is it need not be stored at ultra-low temperatures.
Mechanism-
- Almost all traditional vaccines put a weakened/inactivated virus in the body to generate an immune response.
- An mRNA vaccine instructs the body itself to create a part of the virus.
- The Covid-19 vaccines from Pfizer BioNTech and Moderna both use mRNA to deliver a message to the immune system.
- Genetically engineered mRNA instructs cells to make the spike protein found on the surface of the Covid-19 virus.
- The expectation is that the immune system will mount a response against the spike protein and when an actual infection happens, the immune cells will recognize the spike protein and act against it.
- The advantage of an mRNA vaccine is that it requires a smaller dose than a traditional vaccine, given that the required amount of antigen will be created in the body.
Unique Features-
- mRNA is fragile and breaks down easily, which is the reason to store in low temperatures to prevent breakdown.
- It’s a challenging task to develop a thermostable, vaccine suitable for local needs, affordable and deployable.
- This new vaccine can be stored at the temperature of a standard medical refrigerator.
- GEMCOVAC-19 can be stored at the temperature of a standard medical refrigerator.
- The vaccine is stored in powder form.
- The conversion from liquid to powder form occurs by a process called Lyophilisation/freeze drying which involves freezing the product and subjecting it to a vacuum to remove water.
- Under normal atmospheric pressure ice transforms into liquid water before going into a gaseous state.
- To achieve the conversion of ice to water vapour so that it can be removed, the surrounding pressure and temperature have to be tweaked and then kept stable in a manner that the characteristics of the vaccine are the same as before lyophilisation.
Lyophilisation technique is not new, but a lyophilised mRNA is unique.
Trials & Safety-
- The thermostable vaccine was tested in various animal models to ensure its safety & immunogenicity before entering human clinical trials.
- Phase 1, 2 trial data across 480 participants was submitted first, followed by the presentation of data from Phase 3 trial across 4,000 participants to the Central Drugs Standard Control Organization (CDSCO).
- During the phase 3 trials, 3,000 participants were administered the mRNA Covid-19 vaccine, and 1000 were given Covishield.
- Immunogenicity measured at 2 weeks after the second dose showed that GEMCOVAC-19 is not inferior to covishield.
- The two-dose vaccine will have to be administered intramuscularly, 28 days apart.
Omicron & other variants-
- mRNA vaccine was designed against the Omicron variant which took nearly today.
- This technology platform provides flexibility to quickly tweak the vaccine for any existing or emerging variants.
- A pandemic-ready platform technology created that can be used to quickly develop a vaccine should a variant of concern emerge due to rapid mutation of the SARS-CoV-2 virus.
- Clinical trials need to be done to ascertain the effectiveness of the GEMOVAC-19 against Omicron and sub-variants.
- The approval of the nation’s first mRNA vaccine will pave the way for the development of new variant-specific mRNA vaccines that can be used as a future booster.
- It was necessary to establish the safety and immunogenicity of the new vaccine platform technology in the Indian population.
