mRNA Vaccine Cold Chain: Two Months at 37°C—Where Could Costs Fall?

The AGENT study appeared in Nature Biotechnology on September 28, 2026. Its 37°C test is warmer than ordinary room temperature. These are preclinical findings, not permission to store a licensed vaccine outside its approved conditions.

The Jaklenec–Langer team and why an old fix fell short

Jaklenec and Langer supervised the work. Joint first authors Jinbi Tian and Khanh T. M. Tran designed and performed experiments and analyzed the results. MIT’s Mina Konaković Luković guided algorithm development and interpretation. Formulation research met experimental design. Source: 저자 기여 / Author contributions

MIT describes earlier work by Jaklenec and Langer on polymer-stabilized LNPs, whose composition differed from those in commercial vaccines. Ingredients that had previously worked did not straightforwardly solve Tian and Tran’s new problem. Source: MIT News

Why mRNA vaccine cold chains are difficult

mRNA carries instructions for making a protein. Lipid nanoparticles, or LNPs, protect it and help it enter cells. Preserving RNA alone is insufficient: the particle must still deliver it and the cell must be able to use it. Source: MIT News

The comparison with existing products needs care. The US 2026–2027 SPIKEVAX label permits refrigerated storage at 2–8°C for up to 60 days after thawing, or until the printed expiry date if sooner. At 8–25°C, the limit is 12 hours. It is inaccurate to say every mRNA vaccine requires ultracold storage until injection. Source: SPIKEVAX 처방정보 §16

If Jaklenec’s solid formulation becomes a product, the practical gain could be a longer operating window outside refrigeration. An approved product label and a laboratory result are different kinds of evidence; dividing their storage durations would not establish a performance advantage.

What Tian and Tran asked AI to do

AI selected protective ingredient ratios rather than rewriting the vaccine’s genetic instructions. The team screened nearly 50 excipients and explored combinations of five promising ingredients. Excipients support a medicine’s stability or physical formulation. Source: MIT News

AGENT uses Bayesian optimization: previous experiments inform estimates of promising recipes and uncertain ones, helping select the next candidates. Predictions guide experiments, whose results update the model. The abstract reports six optimization iterations within one month. Source: Nature Biotechnology

1. 1
   Candidate ratios

   Combine protective ingredients

2. 2
   Test and measure

   Assess function after storage

3. 3
   Update model

   Update estimates and uncertainty

4. 4
   Next candidates

   Choose informative experiments

The engineering value is more information from each experiment. Every candidate still requires preparation, drying and measurement. Avoiding unproductive candidates could save staff and equipment time. This is a possible route to lower development cost, not a measured cost-reduction percentage.

What the 37°C result establishes

The team solidified two LNP systems representative of Moderna and Pfizer-BioNTech lipid compositions. The abstract reports 100% retained bioactivity after more than two months at 37°C. That is an activity-assay result, not 100% protection against infection in humans. Source: Nature Biotechnology

MIT describes vacuum drying and mouse immune responses comparable to a reference formulation after storage, including a separate room-temperature study lasting one year. Nature’s research briefing reports immune responses not inferior to fresh vaccine and microneedle-patch delivery in rodents and nonhuman primates. Source: MIT News Source: Nature Research Briefing

Microneedle patches deliver material through tiny dissolving needles. The work therefore points toward additional delivery formats. It does not mean every mouse and primate experiment used identical storage periods, doses or administration routes. Source: Nature Research Briefing

This article verified the public abstract, author information, figure titles and official research accounts. The subscription text and full underlying data were not reviewed. It therefore does not supply unverified primate sample sizes, antibody titers or statistical non-inferiority margins, or infer human safety and protection.

The relevant cost is a completed vaccination

For commercialization, the relevant unit is a completed vaccination. Factory price alone omits refrigeration, transport and doses lost to temperature excursions. The analysis below is a business framework, not a cost study reported in the paper.

Less demanding storage could reduce power, refrigerant and insulated-packaging expenditure, and potentially urgent replacement shipments. WHO identifies limited cold-chain and ice-pack capacity as obstacles to vaccine access. Source: WHO

Manufacturing gains an additional drying step. Batch size and drying-cycle duration affect throughput. Moisture-resistant packaging and residual-moisture testing can add expense. A product requiring reconstitution also needs preparation time and contamination controls. Factory costs could exceed transport savings.

A useful framework is cost per completed vaccination = total manufacturing, packaging, storage, transport and administration cost ÷ completed vaccinations. Lower waste can improve value without lowering the factory price. But better stability alone cannot create purchasing budgets or vaccination staff.

A possible new market is regular supply to small clinics that are uneconomic to serve under existing cold-chain requirements. Whether lower total cost reaches procurement prices depends on competition, licensing and contracts. No country-specific saving or selling price was established here.

What Korean companies could sell

For Korean companies, the question is what capabilities would be needed. Samsung Biologics advertises mRNA/LNP process development, analysis and aseptic filling. In 2022 it announced expanded Songdo mRNA capacity and a commercial-scale engineering run with GreenLight. These show an industrial base, not an AGENT adoption agreement. Nothing here is a recommendation to buy or sell any company’s shares. Source: Samsung Biologics 서비스 Source: 2022년 생산 사례

Contract development and manufacturing organizations, or CDMOs, could offer solid-formulation optimization and scale-up validation. Customers would need consistent quality across batches and evidence for their own RNA and lipid compositions. Investment would need to follow customer specifications and validation requirements.

Korean vaccine developers could design export products around storage and administration needs from the outset. Commercial patches might create demand for patch manufacturing and packaging, but would require product-level validation of delivered dose and variability between users.

Logistics revenue could shift from premium frozen transport toward tracking, inventory visibility and quality-assured delivery for the affected products. Other biologics would retain their own requirements. The result would not imply wholesale replacement of cold-chain logistics; savings for one participant may require transition spending by another.

Before commercialization: scale-up, humidity and WHO criteria

Translation requires reproducibility in factories and distribution. Packaging, humidity, fluctuating temperatures and conditions after opening matter. Longer drying cycles or higher rejection rates at scale could erode the laboratory advantage.

WHO’s controlled temperature chain, or CTC, is not unrestricted ambient storage. It requires an appropriate stability profile for a single exposure of at least three days at a minimum of 40°C immediately before administration, within approved specifications. AGENT’s 37°C result does not automatically meet that requirement. Source: WHO ECTC

Jaklenec and colleagues offer a route to more efficient formulation discovery and broader distribution conditions. Commercial value will depend on manufacturing yield, human evidence, product-specific storage authorization and procurement. The decisive number will be how many additional vaccinations the same budget can deliver.

---

The economic value of stability depends on how many more vaccinations the same budget delivers.

Sources and further reading

• Tian et al., Nature Biotechnology (2026): AGENT
• Nature Biotechnology Research Briefing: AI-guided optimization
• MIT News: New formulation helps RNA vaccines withstand high temperatures
• WHO: Extended Controlled Temperature Conditions
• SPIKEVAX 2026–2027 미국 처방정보, §16 (2026년 8월 개정)
• Samsung Biologics: mRNA Manufacturing and Development Services
• Samsung Biologics·GreenLight: commercial-scale engineering run (2022)