mRNA is the vaccine development technology that redefined vaccine-making!
Last week, we began the mRNA series with an introduction to mRNA, examining what it is and why it matters for the future of medicine.
We took a quick glimpse at the basic biology of mRNAs and how they function at a molecular level.
Today, we will briefly explore how mRNA technology redefined the industry of vaccine making and how it prevented a pandemic from becoming something beyond catastrophic.
When COVID-19 struck, the world needed a vaccine fast.
Traditional vaccine development takes 10–15 years.
Yet within months, two vaccines—Pfizer-BioNTech’s BNT162b2 and Moderna’s mRNA-1273—were developed and saved millions of lives.
How? The answer lies in messenger RNA (mRNA), a technology that has been quietly maturing for decades.
What Is An mRNA Vaccine?
mRNA vaccines don’t contain the live virus. Instead, they deliver genetic instructions to cells, teaching them to make a harmless version of the coronavirus spike protein.
- Once made, the spike protein triggers an immune response—antibodies, T cells, and memory cells.
- If the real virus enters later, the immune system is ready to fight.
- The mRNA itself never enters the nucleus, doesn’t alter DNA, and degrades naturally within days (CDC explainer).
Built On Decades Of Science
The “overnight success” of mRNA vaccines was built on 30 years of research:
- Katalin Karikó and Drew Weissman discovered how to modify nucleosides, stabilising mRNA and reducing unwanted immune reactions.
- Lipid nanoparticles (LNPs) were developed to shield fragile mRNA and deliver it into cells.
- Early experiments in animals demonstrated that the concept could be effective (Virology Journal).
How Pfizer And Moderna Did It
- January 2020: Chinese scientists published the SARS-CoV-2 genome. Within days, Moderna and BioNTech designed candidate mRNAs encoding the spike protein (Nature).
- March 2020: Moderna launched its Phase 1 trial. Pfizer/BioNTech followed shortly after.
- December 2020: Both vaccines received emergency use authorisation.
Clinical Trial Highlights:
- Moderna (mRNA-1273): ~94% efficacy against symptomatic COVID-19; ~86% in adults 65+ (NEJM study).
- Pfizer-BioNTech (BNT162b2): ~95% efficacy across age groups 16+ (NEJM study).
Real-World Impact
- Hospitalisations Prevented: Among adults 65+, Pfizer and Moderna reduced hospitalisations by ~94% (Axios report).
- Variants: Protection against infection dipped with Beta, Delta, and Omicron—but vaccines stayed strong against severe disease (review).
- Scale: From genome release to authorisation took less than 11 months—a record in vaccinology!
Challenges And Lessons
- Cold Chain: Pfizer’s vaccine initially required ultra-cold storage, presenting global distribution challenges, particularly in areas with limited resources.
- Equity: Wealthy nations got doses first, while low-income countries waited (WHO statements).
- Safety: Side effects were mostly mild; rare adverse events were tracked through global monitoring systems (CDC).
The Road Ahead
mRNA is now being tested for:
- Seasonal Flu
- HIV And Malaria
- Cancer Immunotherapy
- Pan-coronavirus Vaccines to protect against future outbreaks
Quick Facts: mRNA & COVID-19
- First mRNA vaccines ever authorised: Pfizer-BioNTech & Moderna (2020).
- Time from genome sequence to vaccine rollout: ~11 months.
- Clinical trial efficacy: ~95% (Pfizer), ~94% (Moderna).
- Key innovation: modified nucleosides + lipid nanoparticles.
- Real-world impact: prevented millions of hospitalisations and deaths.
Key Takeaway
mRNA vaccines didn’t just help control the COVID-19 pandemic—they redefined what’s possible in vaccine science.
What once took a decade can now be done in a year. And with this platform, the world may be better prepared for the next pandemic.
Science is progressive, and there’s still a lot that we can learn about mRNA, especially possible adverse effects, and as we understand it better, we can create pathways to navigate effectively through challenges.
We started the mRNA series last week.
We’re doing this so more people (not just healthcare professionals and scientists) can know more about mRNA technology and be armed with the correct scientific knowledge to combat misinformation.
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