Will Moderna receive regulatory approval for mRNA-1010 (flu vaccine) in the EU, Canada, or Australia by December 31, 2026?

EMA standard review timeline is ~210 days from validation. If validated around February 2026, the CHMP opinion would land around September-October 2026 -- well within the resolution window. The CHMP positive opinion counting as YES per resolution criteria is a meaningful relaxation that avoids the additional delay of EC decision. The Phase 3 data is exceptionally strong: 26.6-27% higher efficacy in 40,700 adults with no safety concerns, using a comparator design that has precedent in two prior approved flu vaccines (Fluzone HD, Fluad). Clock-stops for information requests are the primary risk, but the clean safety profile and established trial design make major questions unlikely. Having three independent regulatory agencies provides substantial timeline diversification -- even if one agency runs slow, the others may complete.

The international acceptance of the identical application that FDA refused to file is the strongest evidence that the science is sound and the U.S. RTF was politically motivated. This framing matters because it means international regulators are evaluating a scientifically valid application, not a borderline one. The Phase 3 data (26.6-27% higher efficacy, no safety concerns, 40,700 participants) with well-established comparator design gives high confidence in eventual approval. The key uncertainty is purely timeline-based: 'earliest potential approvals: late 2026 or early 2027' from the dossier suggests the timeline straddles the resolution date. If I assign ~88% probability to eventual approval by any of the three agencies and ~80% probability that at least one completes by Dec 31, the combined probability is approximately 0.70-0.75.

Considering downside scenarios: all three regulators could delay past December 2026 if major information requests or unexpected safety signals emerge. However, three factors make this unlikely: (a) the Phase 3 trial was large (40,700 adults 50+) with clean safety, (b) two prior flu vaccines used similar standard-dose comparator designs and were approved, (c) three independent agencies provide diversification against any single agency's delays. The main correlation risk is if one agency identifies a question that causes others to pause -- but with strong safety data, this is a low-probability scenario. Regulatory timeline variability is the dominant uncertainty. The dossier's 'earliest potential approvals: late 2026 or early 2027' places us in a zone of genuine uncertainty about timing, which I weight at roughly 25% chance of all three missing the Dec 31 deadline.

Three regulatory agencies accepted a filing that the FDA refused. The Phase 3 data is unambiguously strong: 26.6-27% higher efficacy vs standard dose in 40,700 adults with no safety concerns. Prior precedent exists -- Fluzone HD and Fluad were approved using similar comparator designs. The resolution criteria helpfully include CHMP positive opinion (not just full EC authorization), which shortcuts the EMA timeline by several months. With three shots on goal and strong science, the question reduces to: will at least one agency complete a standard review within ~10-11 months of filing? EMA averages ~12 months but CHMP opinion comes earlier. Health Canada can prioritize. This is more likely than not to resolve YES.

Regulatory timelines are notoriously variable and 'earliest potential approvals: late 2026 or early 2027' from the dossier itself signals the timeline is tight. Standard EMA procedures include a 210-day active review period plus potential clock-stops that can add 3-6 months for questions. Health Canada's standard review is ~300 days. TGA's standard registration is 255 working days. Each of these puts the base-case completion around Q4 2026 or Q1 2027 -- right on the boundary. While three agencies help, regulatory reviews are not fully independent (they share the same data package and may raise similar questions). The strong data reduces rejection risk but doesn't eliminate timeline risk. I'm less optimistic than a pure probability calculation would suggest because 'accepted for review' is a low bar and standard timelines are optimistic.

Building a probability tree: for each agency, I estimate ~88-92% approval probability given accepted filing + strong Phase 3 data + prior precedent. For timing (completing by Dec 31, 2026), I estimate: EMA/CHMP ~65% (210-day review from Feb puts opinion in Sep-Oct, but clock-stops common), Health Canada ~60% (300-day standard, ~55% priority designation possibility), TGA ~55% (255 working days from filing). Probability of at least one completing: 1 - (0.35 * 0.40 * 0.45) = 1 - 0.063 = 93.7%. But adjusting for approval risk and correlation between agencies, I reduce to ~73%. The key insight is that the CHMP opinion counting as YES for EMA significantly helps -- CHMP opinions precede EC authorization by 2-3 months, bringing EMA into the window.

Strong Phase 3 data (26.6-27% higher efficacy, 40,700 adults, no safety concerns) with prior precedent (Fluzone HD, Fluad). Three agencies accepted the filing. CHMP positive opinion counts as YES for EMA, reducing the effective timeline. Main risk is purely timing -- 'late 2026 or early 2027' straddles the deadline. With three shots, probability of at least one completing by year-end is high.

Dossier states 'earliest potential approvals: late 2026 or early 2027' -- the word 'earliest' suggests optimistic case. Standard regulatory review timelines are variable with common clock-stops. Three agencies help diversify but are not fully independent. The strong data package reduces scientific risk to near-zero. Purely a timing question with moderate probability of meeting the Dec 31 deadline.

Three agencies accepted what FDA refused -- science is clearly sound. Phase 3 showed 26.6-27% higher efficacy with no safety issues in 40,700+ adults. Similar designs (Fluzone HD, Fluad) have been approved before. The CHMP opinion counting as YES is a meaningful concession that brings EMA into the timing window. At least one of three agencies is likely to complete review by year-end given strong data and established precedent.