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Elasomeran

  • Vaccine
  • Given by a clinician
  • Identity checked
  • Sources last checked 2026-09-04

This page shows what was measured, who it was measured in, and what that does not settle.

What Elasomeran does in the body

Used to prevent COVID-19, especially in older or higher-risk people.

It works the same way its Pfizer counterpart does: a fat droplet carries a recipe for one coronavirus surface protein into cells near the injection site, they build it, and the immune system learns the shape. The differences are in the details, and the details matter. The dose of RNA was larger in the pivotal trial, the fat mixture is different, and this trial swabbed people who felt fine, so it could see infections the other trial could not.

What happened in people

Eleven vaccinated people developed symptomatic COVID-19, compared with 185 people given a dummy injection.

Reviewed first-read answer

Where this came from

A person wrote this and a reviewer approved it against this exact record. It carries no effect size.

A reviewer approved this against this record. The reviewed-claim record carrying the exact population and effect size does not exist yet.

No source is stored against this line.

The limit that matters most

Only one person died of COVID-19, too few to prove a survival benefit.

Where it acts
Deltoid muscle and the draining axillary lymph node; translation occurs in the cytoplasm of muscle cells and antigen-presenting cells
Kind of result
The kind of result is not recorded
Supervision
Professional supervision is normally required. It is a prescription or clinician-administered medicine where it is approved.

What the registries record it as

  • The substance registry classes this as nucleicacid.

    FDA substance registry · EPK39PL4R4 · read 2026-08-29

Where each sentence above came from

No recorded sentence describes the change this makes in a way that stands on its own. The page opens with what it is taken for instead, and the recorded explanation follows below.

Shown as the opening line on this page.

The limit a reviewer approved as the one that matters most here.

The four opening statements run to 105 words.

Words this page uses

Four words worth knowing first

Chosen from what this page shows, with each one explained before the word it depends on.

Messenger RNA

Messenger RNA is a working copy of one gene, carried to where proteins are built.

A picture of it, and where the picture fails

It is like a photocopy of one plan page, taken to the workshop.

Where that stops being true. A photocopy lasts. This copy is destroyed soon after use, on purpose.

What people get wrong. It is often thought to change the gene. It is a copy, and it does not alter the original.

A single-stranded transcript of a gene that ribosomes translate into a protein.

Small interfering RNA

A small interfering RNA is a short piece that makes a cell destroy one working copy.

A picture of it, and where the picture fails

It is like a note telling the workshop to shred one plan page.

Where that stops being true. A note is read once. This keeps working for months after one injection.

What people get wrong. It is often described as gene editing. It leaves the gene untouched.

A short double-stranded RNA that directs the RNA-induced silencing complex to cleave a complementary transcript.

Absolute difference

An absolute difference is how many more people in a hundred were affected.

A picture of it, and where the picture fails

It is like counting heads in two rooms of a hundred.

Where that stops being true. Heads are easy to count. Study results carry a margin of error too.

What people get wrong. It is confused with a percentage change, which can look far larger.

The arithmetic difference in event rates between arms.

Confidence interval

A confidence interval is the range the true answer is likely to sit in.

A picture of it, and where the picture fails

It is like a weather forecast giving a range rather than one number.

Where that stops being true. A forecast range covers tomorrow. This one covers what the study could resolve.

What people get wrong. The middle number is read as the answer. A range crossing zero means no change is still possible.

An interval estimate that would contain the true parameter in a stated proportion of repeated studies.

What happened in peopleRead from sources, not yet reviewed

What happened in people

Each card is one study: the exact question it asked, who was in it, and whether it showed what it set out to show.

Prevention of symptomatic COVID-19 with onset at least 14 days after the second injection in participants without prior SARS-CoV-2 infection

The study showed what it set out to show

Who was studied
COVE primary analysis (NCT04470427)
How many people
30420
Study design
Phase 3
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
P<0.001; 94.1% efficacy, 95% CI 89.3 to 96.8
Repeated elsewhere
Replicated

What this does not prove. Meeting one endpoint in one population does not carry to other goals or other people.

The limits of this study, and where it came from

Main limit. Myocarditis was not detected in the trial. Its excess in males 16 to 24 was quantified only later, in Nordic national registers.

How far it carries. This study is recorded from the curated record, not from the registry match.

Form and route. Ionisable lipid nanoparticle, intramuscular

Interval reported. 95% CI 89

Written into the record, not signed off as a reviewed claim.

Prevention of symptomatic COVID-19 through completion of the blinded phase, median follow-up 5.3 months

The study showed what it set out to show

Who was studied
COVE blinded-phase completion (NCT04470427)
How many people
30415
Study design
Phase 3
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
93.2% efficacy, 95% CI 91.0 to 94.8
Repeated elsewhere
Replicated

What this does not prove. Meeting one endpoint in one population does not carry to other goals or other people.

The limits of this study, and where it came from

Main limit. No limitation is recorded for this study.

How far it carries. This study is recorded from the curated record, not from the registry match.

Form and route. Ionisable lipid nanoparticle, intramuscular

Interval reported. 95% CI 91

Written into the record, not signed off as a reviewed claim.

What we know
RNAWiki holds 2 written-up human studies for this substance, each with the question it asked.
How we know it
Each card names the study, the number of people and what the study set out to measure.
What this does not prove
These summaries were written by a person and have not been signed off as reviewed claims.
Why it matters
A study that failed is as informative as one that worked, and both are here.
What we still do not know
No reviewed claim exists, so no exact population, effect size or interval is published yet.

What it changes in the bodyRead from sources, not yet reviewed

The path through the body

From what a person takes to what changes. A solid line is a step measured in people. A dashed line is a step nobody has measured that way.

  1. Start

    Elasomeran

    What a person takes: Ionisable lipid nanoparticle, intramuscular.

    The measurement behind this step

    A 0.5 mL intramuscular dose of the 2025-2026 formula contains 50 micrograms of nucleoside-modified mRNA with 1.01 mg total lipid (SM-102, PEG2000-DMG, cholesterol, DSPC), tromethamine buffer, sodium acetate and 43.5 mg sucrose. The paediatric 0.25 mL presentation contains 25 micrograms.

  2. Getting in

    Intramuscular dose and particle uptake

    A half-millilitre injection into the shoulder muscle. The fat droplets are taken up by muscle cells and by immune cells at the site and in the nearby lymph node.

    Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.

    The measurement behind this step

    SM-102 is the ionisable lipid here, paired with PEG2000-DMG, DSPC and cholesterol at a total lipid content of 1.01 mg per 0.5 mL dose. Apolipoprotein E adsorption and receptor-mediated endocytosis deliver the particle to myocytes and to dendritic cells trafficking to the draining node.

  3. Reaching the cell

    Acid-triggered endosomal escape

    The droplet ends up in an acidic bubble inside the cell. The acid changes the charge on one of the fats, the bubble wall gives way, and part of the cargo reaches the cell body.

    Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.

    The measurement behind this step

    Protonation of the SM-102 tertiary amine at endosomal pH creates ion pairs with anionic endosomal lipids and destabilises the bilayer. Escape efficiency is low, single-digit percentages in most published measurements, which is a large part of why the required dose is measured in tens of micrograms.

  4. What it acts on

    Translation of a modified transcript

    The cell reads the recipe. A modified letter in the RNA keeps the cell from raising an alarm that would shut translation down.

    Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.

    The measurement behind this step

    N1-methylpseudouridine substitution reduces TLR7, TLR8 and RIG-I activation and raises translational output. A cap-1 structure installed by vaccinia capping enzyme with 2-prime-O-methyltransferase marks the transcript as self and permits efficient eIF4E-dependent initiation.

  5. The change it makes

    Prefusion spike trimer on the cell surface

    The cell assembles the coronavirus surface protein and holds it in the shape it takes before it fuses with a cell, which is the shape antibodies need to learn.

    Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.

    The measurement behind this step

    Two consecutive proline substitutions in S2 stabilise the prefusion trimer, exposing the receptor-binding domain and the N-terminal domain supersite. Surface display supports B-cell receptor crosslinking; proteasomal processing supplies MHC class I peptides for CD8 priming.

  6. What that does for a person

    Antibody, T cells, and measurable protection from silent infection

    The immune response that follows cut symptomatic illness by 94% and, in this trial, cut infections without symptoms by 63%.

    Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.

    The measurement behind this step

    Germinal centre output gives neutralising IgG against the receptor-binding domain plus CD4 Th1-skewed and CD8 memory. Mucosal IgA is induced weakly by intramuscular dosing, which is the mechanistic reason protection against infection is both smaller and shorter-lived than protection against severe disease.

No suggested links are held for this record, so nothing is hidden from this path.

What we know
The record describes 5 steps from taking it to an effect in a person.
How we know it
Each step names the study behind it in the technical detail beside it.
What this does not prove
A change inside the body is a reason to look. It is not a result in a person.
Why it matters
A reader can see exactly where the chain stops being measured in people.
What we still do not know
No reviewed claim binds any of these steps to a named population.

What is missing or unclearRead from sources, not yet reviewed

Were people like you studied?

RNAWiki cannot tell whether a study fits you. It can show who was in it, and where the result stops carrying.

Who was studied

People similar to this profile were included.

  • Under the current US label, adults 65 and older, and people aged 6 months through 64 years with at least one condition that raises their risk of severe COVID-19.

Who is missing from the studies

  • Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.

Where the result stopped carrying

  • Unmodified mRNA was too immunogenic as a molecule and too poorly translated to work as a vaccine
  • The first-generation formulation required ultracold storage, which constrained distribution for a year
  • Several Nordic regulators paused or restricted this product in young males once the register data landed
  • This is a scope explorer, not a diagnosis engine.
  • It shows who was studied so you can see whether people similar to you were included.

RNAWiki cannot tell whether a study fits you. It can show who was in it.

What it would be like to takeRead from sources, not yet reviewed

Why it might seem to do nothing

A real effect and a noticed effect are different things. These are the recorded reasons the two come apart.

It was studied in different people

The people in the studies were not much like the reader.

On this record: Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.

The evidence may simply be wrong

Small early studies often do not hold up.

On this record: RNAWiki has not yet published a reviewed conclusion for this use.

Other reasons RNAWiki checked and found nothing for (11)
It was studied for a different goal
The studies measured something else entirely. Nothing in this record points to this reason.
A different form was studied
The studied form is not the form on the shelf. Nothing in this record points to this reason.
There was nothing to correct
Where a level is already normal, topping it up may change nothing. Nothing in this record points to this reason.
Something else had to happen too
In the studies it was paired with training, a diet or another treatment. Nothing in this record points to this reason.
The change is too small to feel
A real change can still sit below what a person notices. Nothing in this record points to this reason.
Day-to-day swing hides it
Sleep, food, stress and time of day move most numbers more than this would. Nothing in this record points to this reason.
Not enough time yet
The studies ran longer than the person has waited. Nothing in this record points to this reason.
It was not taken as studied
Missed days change the result, and studies count them. Nothing in this record points to this reason.
Something else changed at the same time
Two changes at once cannot be told apart afterwards. Nothing in this record points to this reason.
The product may not be what it says
Contents of a sold product are not always what the label states. Nothing in this record points to this reason.
No recorded reason
RNAWiki has nothing stored that would explain it. Nothing in this record points to this reason.

None of these is a reason to take more. Taking more is not a step this page ever suggests.

What it would be like to takeRead from sources, not yet reviewed

What taking it involves

The recorded facts about getting hold of it and using it. Nothing here is a suggestion about what you should do.

How it is supplied

Given by a clinician

Quoted from a source

Where this came from

Copied from a source RNAWiki stored, with the source named.

Read from the recorded approval status.

No source is stored against this line.

Form and route

Ionisable lipid nanoparticle, intramuscular

Source-linked record

Where this came from

A person wrote this into the record with the study named beside it. No reviewer has signed it off.

The form and route recorded on this substance.

No source is stored against this line.

Who oversees it

Professional supervision is normally required. It is a prescription or clinician-administered medicine where it is approved.

Quoted from a source

Where this came from

Copied from a source RNAWiki stored, with the source named.

The identity record classes it as mRNA Vaccine / Therapeutic.

No source is stored against this line.

What is in the pack

5 mg sucrose. 25 mL presentation contains 25 micrograms.

Source-linked record

Where this came from

A person wrote this into the record with the study named beside it. No reviewer has signed it off.

Recorded notes on how this is sold and what that means for what is in the pack.

No source is stored against this line.

Where it is registered

Regulatory records are listed in the technical disclosure at the foot of this page.

Counted from records

Where this came from

A count of rows RNAWiki holds. It describes our records, not your body.

Register entries are stored per jurisdiction and shown with their dates.

No source is stored against this line.

Why people stop

Not recorded.

Nothing recorded

Where this came from

RNAWiki holds nothing here and says so rather than guessing.

No record of why people stopped taking it is stored for this substance.

No source is stored against this line.

What it would be like to takeRead from sources, not yet reviewed

What can go wrong

Sorted by where each line came from. A regulator's label and a report somebody sent in are not the same kind of fact.

Worth asking a clinician aboutWritten into the record from the studies named on this page

Reactogenicity is more pronounced than with the Pfizer product: fever, chills and fatigue after the second dose are common and transient. Myocarditis and pericarditis are concentrated in males 16 to 24, at an estimated 18.39 excess events per 100,000 second doses in that group. Anaphylaxis is rare.

Nobody counted how many people took this and were fine, so this cannot be turned into a rate.

Where this came from

Over a long time. No completed tested study window is recorded, so long-term effects are not established by the registry record.

Groups the studies covered thinly. Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.

What is missing or unclearNothing found in the sources checked

Does the exact form matter?

Evidence belongs to the exact thing that was tested. A different salt, a different mixture or a different preparation is a different question.

The form that was studied

Ionisable lipid nanoparticle, intramuscular

Source-linked record

Where this came from

A person wrote this into the record with the study named beside it. No reviewer has signed it off.

The form used in the studies cited on this page.

No source is stored against this line.

What is sold

5 mg sucrose. 25 mL presentation contains 25 micrograms.

Source-linked record

Where this came from

A person wrote this into the record with the study named beside it. No reviewer has signed it off.

Recorded notes on which forms are sold and how they compare.

No source is stored against this line.

Evidence carries across two names for one substance. It does not carry across a salt, a mirror form or a mixture.

What it would be like to takeRead from sources, not yet reviewed

What you could measure

This one is decided with a clinician, so this section holds questions to ask rather than a plan to run.

Self-experiment planning is not offered for a prescription or clinician-supervised medicine. The questions below are for a clinician or pharmacist.

Questions worth asking

  • Which of the trials of Elasomeran studied people like me?
  • What was measured, and for how long?
  • Was the result a laboratory value or a health outcome?
  • What would we watch for, and when would we stop?

Tracking can show whether something changed for you. It cannot show what caused it.

RNAWiki records evidence. It does not say whether this substance is right for you.

What is missing or unclearRead from sources, not yet reviewed

Claims that go past the evidence

Things said about this substance that sound reasonable, and the exact step that is missing between the evidence and the claim.

Goes past the evidence

That the trial demonstrated a mortality benefit: exactly one COVID-19 death occurred in the blinded phase

Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.

The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.

What would change this

A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.

RNAWiki has not yet published a reviewed conclusion for this use.

Goes past the evidence

That 63% against asymptomatic infection means the vaccine blocks transmission; blocking is partial and was measured indirectly

Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.

The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.

What would change this

A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.

RNAWiki has not yet published a reviewed conclusion for this use.

Goes past the evidence

That the 100 microgram ancestral-strain result describes the 50 microgram omicron-strain product sold today

Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.

The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.

What would change this

A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.

RNAWiki has not yet published a reviewed conclusion for this use.

What is missing or unclearRead from sources, not yet reviewed

What nobody knows yet

Open questions, each with why it is open and what would close it.

How much did people take in the studies?

The sources RNAWiki checked hold nothing for this field.

Why it matters. A result belongs to an amount. Without the amount the result floats free.

What would answer it

A stored source that records it, and a reviewer to sign it off.

Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.

Missing populations

Which groups were under-represented in the studies has not been recorded.

Why it matters. Recorded by the evidence model as a gap on this record.

What would answer it

A study that measures it, and a reviewer to sign it off.

Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.

Missing long-term data

No completed tested study window is recorded.

Why it matters. Recorded by the evidence model as a gap on this record.

What would answer it

A study that measures it, and a reviewer to sign it off.

Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.

No reviewed conclusion

RNAWiki has not yet published a reviewed conclusion for this use.

Why it matters. Recorded by the evidence model as a gap on this record.

What would answer it

A study that measures it, and a reviewer to sign it off.

Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.

Missing interaction studies

No interaction was found in the registers checked. Not finding one is not the same as showing there is none.

Why it matters. Recorded by the evidence model as a gap on this record.

What would answer it

A study that measures it, and a reviewer to sign it off.

Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.

Formulation uncertainty

Several salts, forms or products of Elasomeran are recorded. Results from one form may not transfer to another.

Why it matters. Recorded by the evidence model as a gap on this record.

What would answer it

A study that measures it, and a reviewer to sign it off.

Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.

Mechanism not reviewed

No reviewed mechanism story exists for this substance.

Why it matters. Recorded by the evidence model as a gap on this record.

What would answer it

A study that measures it, and a reviewer to sign it off.

Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.

What happened in peopleRead from sources, not yet reviewed

Check any of this yourself

Every line above traced back to the study it came from. This is the technical layer, and the vocabulary changes here.

Every line above can be traced to the study named beside it. Follow the link and read it.

COVE: 94.1% efficacy against symptomatic COVID-19
In plain words
Eleven vaccinated participants and 185 placebo participants developed symptomatic COVID-19. All 30 severe cases were in the placebo group.
What was measured
94.1% efficacy against symptomatic COVID-19 (95% CI 89.3 to 96.8)
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Phase 3, observer-blinded, placebo-controlled trial at 99 US centres. 30,420 enrolled, randomised 1:1 to two 100 microgram doses 28 days apart. Symptomatic COVID-19 with onset at least 14 days after the second injection occurred in 11 vaccine recipients (3.3 per 1,000 person-years) and 185 placebo recipients (56.5 per 1,000 person-years), giving 94.1% efficacy (95% CI 89.3 to 96.8, P<0.001). All 30 severe cases, including the one fatality, were in the placebo group.
Source
Baden et al., New England Journal of Medicine, 2021
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
verified
Review state
Written into the record, not signed off as a reviewed claim
This trial did measure asymptomatic infection, and got 63.0%
In plain words
Because participants were swabbed at scheduled visits whether or not they felt ill, this trial could put a number on silent infection. The number was much lower than the headline.
What was measured
63.0% efficacy against asymptomatic infection; 93.2% against symptomatic disease at completion of the blinded phase
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
At completion of the blinded phase, with 30,415 participants and a median 5.3 months of follow-up, efficacy against symptomatic COVID-19 was 93.2% (95% CI 91.0 to 94.8) with 55 cases against 744, and 98.2% (95% CI 92.8 to 99.6) against severe disease. Efficacy against asymptomatic infection starting 14 days after the second injection was 63.0%. That last number is the one worth remembering when someone claims an mRNA vaccine either does or does not stop infection.
Source
El Sahly et al., New England Journal of Medicine, 2021
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
verified
Review state
Written into the record, not signed off as a reviewed claim
Myocarditis risk in young men is measurably higher than with the Pfizer vaccine
In plain words
Across four Nordic countries and 23 million residents, second doses of this vaccine produced roughly three times the excess myocarditis of the Pfizer vaccine in males aged 16 to 24.
What was measured
18.39 excess myocarditis events per 100,000 second doses in males aged 16 to 24
Effect estimate
No reviewed effect estimate exists for this record.
Limits
This entry records a failure.
From the source
Cohort study of 23,122,522 residents of Denmark, Finland, Norway and Sweden followed to 5 October 2021, with 1,077 incident myocarditis events. In males aged 16 to 24 receiving a homologous schedule, the adjusted incidence rate ratio in the 28 days after the second dose was 13.83 (95% CI 8.08 to 23.68) for mRNA-1273 against 5.31 (95% CI 3.68 to 7.68) for BNT162b2. Excess events were 18.39 per 100,000 vaccinees (95% CI 9.05 to 27.72) for mRNA-1273 and 5.55 (95% CI 3.70 to 7.39) for BNT162b2. Several Nordic regulators restricted this product in young men on the strength of it.
Source
Karlstad et al., JAMA Cardiology, 2022
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
caution
Review state
Written into the record, not signed off as a reviewed claim
Efficacy against death was never demonstrated by this trial on its own
In plain words
One person died of COVID-19 during the blinded phase, in the placebo group. A single event cannot establish a mortality benefit.
What was measured
That the pivotal randomised trial demonstrated a reduction in COVID-19 deaths.
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
COVE was powered on symptomatic COVID-19, not on death. The single COVID-19 death in the blinded phase was in the placebo arm. That is consistent with a mortality benefit and is not a measurement of one. The claim that mRNA vaccination reduces COVID-19 mortality rests on the 98.2% efficacy against severe disease plus large observational cohorts, not on counted deaths inside this randomised trial.
Source
El Sahly et al., New England Journal of Medicine, 2021
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
caution
Review state
Written into the record, not signed off as a reviewed claim
Dose, strain and eligible population have all changed since the pivotal trial
In plain words
The trial used 100 micrograms of ancestral-strain mRNA in adults of any risk level. The product now sold is 50 micrograms of an omicron-strain sequence for a restricted population.
What was measured
Not recorded
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Each 0.5 mL dose of the 2025-2026 formula contains 50 micrograms of mRNA encoding the spike of omicron sublineage LP.8.1; the 0.25 mL paediatric presentation contains 25 micrograms. The label restricts use to people 65 and older, or 6 months through 64 years with at least one high-risk condition. Half the dose, a different antigen and a different population: the 94.1% figure describes none of those things.
Source
SPIKEVAX US prescribing information, DailyMed
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
verified
Review state
Written into the record, not signed off as a reviewed claim
Protection against infection wanes; protection against severe disease holds longer
In plain words
The English variant study found two mRNA doses gave little protection against catching symptomatic omicron six months on, even while severe outcomes stayed rarer.
What was measured
Not recorded
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
In the same test-negative study that covered 886,774 omicron infections, two mRNA-1273 doses followed the same pattern as BNT162b2: substantial short-term effectiveness against symptomatic omicron that decayed steeply by 25 weeks, with boosters restoring it temporarily. Effectiveness against hospitalisation and death decayed far more slowly, which is the reason the current label targets the people for whom that second curve matters most.
Source
Andrews et al., New England Journal of Medicine, 2022
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
verified
Review state
Written into the record, not signed off as a reviewed claim

Where else this substance is registered

FDA substance identifier (UNII)
EPK39PL4R4
CAS registry number
2430046-03-8
WHO international nonproprietary name list entry
12065
EMA substance identifier
300000015561
DrugBank
DB15654

Checks this page had to pass

  • Passed

    Identity resolved

    no open identity hold

  • Passed

    No unresolved merge across substance families

    no quarantine open

  • Passed

    Every public sentence names a source

    The opening statement carries the origin: Reviewed first-read answer.

  • Not passed

    Trial roles classified for highlighted evidence

    No registered study is classified as testing this substance.

  • Passed

    No internal keys in reader text

    enforced by the copy-contract test over the rendered page

  • Passed

    Safety mode resolved

    The identity record classes it as mRNA Vaccine / Therapeutic.

  • Passed

    Canonical metadata present

    slug and display name present

What is missing or unclearRead from sources, not yet reviewed

What to learn next

Ordered by what would most change how you read this page, starting with what is easiest to misunderstand.

This order is fixed in code and does not count clicks or time on the page.

What is not here

8 questions this page could not answer

These sections were prepared and left out because there was nothing to put in them. They are listed rather than hidden, so the gaps in this record are visible.

  • What was measured, goal by goal — found nothing in the sources checked.
  • How close this is to real life — found nothing in the sources checked.
  • Felt, measured, or meaningful — found nothing in the sources checked.
  • How long anything takes — found nothing in the sources checked.
  • What it may clash with — found nothing in the sources checked.
  • Other ways to the same goal — found nothing in the sources checked.
  • How this medicine reached us — found nothing in the sources checked.
  • What changed on this page — found nothing in the sources checked.

The record as stored

The full record, for auditing

Everything above is built from what is below. This layer keeps the technical vocabulary, record identifiers and every stored row, so a reader who wants to check the page can.

The older medicine-wide conclusion held in this record

Written for a clinical reader, and about the medicine as a whole rather than about one indication, population and set of trials. RNAWiki does not treat it as a programme conclusion and no reviewer has signed it off in that form. It is here word for word because it is what the record holds.

The same nucleoside-modified spike mRNA platform at a larger dose, which cut symptomatic COVID-19 by 94.1% in 30,415 randomised adults and, unusually, also measured a 63.0% cut in asymptomatic infection.

Recorded evidence blocks (5)

14 registered trials of Elasomeran — at which phases?


Registered studies posting no result
9 of 14

14 registered studies of Elasomeran: 5 phase2, 4 phase3, 3 na or unstated, 2 phase4. CLINICALTRIALS_SNAPSHOT · 2026-09-01

0 with a PubMed record

Show the evidence
  • phase2
    5
  • phase3
    4
  • na or unstated
    3
  • phase4
    2
  • completed
    7
  • active not recruiting
    2
3 more recorded rows
  • terminated
    2
  • withdrawn
    2
  • unknown
    1

recorded 2026-09-01 · last checked 2026-09-04

4 of Elasomeran's trials stopped: accrual/recruitment, funding/business, other?


accrual/recruitment (1), funding/business (2) and other (1): Elasomeran's stop wording, clustered. CLINICALTRIALS_SNAPSHOT · 2026-09-01

"The population as defined by the inclusion/exclusion criteria and the study logistics were leading to a poor recruitment over the past years."; 4 of 14 registered studies

Show the evidence

Trial

  • NCT05075538
    terminated; "The population as defined by the inclusion/exclusion criteria and the study logistics were leading to a poor recruitment over the past years."
  • NCT05228730
    terminated; "Due to the small number of participants"
  • NCT05387317
    withdrawn; "Trial cancelled prior to commencement due to lack of funding."
  • NCT05543356
    withdrawn; "Withdrawal of supply of vaccine from one manufacturer"

recorded 2026-09-01 · last checked 2026-09-04

Which 2 trials of Elasomeran posted no result?


Posted no result
2 of 2 completed trials
Registrations
NCT05383560 and NCT06130345
Completion dates
oldest 2024-01-31; newest 2024-08-31
Show the evidence

Trial

  • NCT05383560
    2024-01-31
  • NCT06130345
    2024-08-31

At the median, Elasomeran's trials enrolled 116.5 people — anything larger?


Median enrolment
116.5
Largest enrolment
15196685
Registered trials counted
14

What do 52 spontaneous reports say about Elasomeran — and not say?


These are reports people sent to a regulator. They do not show the medicine caused the reaction. Nobody counted how many people took the medicine and reported nothing. The same event can be reported more than once, and many reports are incomplete. News coverage, lawsuits and new warnings change how often people report. A count is not a rate and not a risk.

Elasomeran appears in spontaneous reports to regulators. Across the 10 most-reported reaction terms, 52 reaction mentions were counted: chest pain 9; covid-19 9; pemphigoid 7; myocarditis 5. FAERS via Open Targets · CHEMBL4650491 · 2026-06-24

Show the evidence
  • chest pain
    9
  • covid-19
    9
  • pemphigoid
    7
  • myocarditis
    5
  • chills
    5
  • toxic epidermal necrolysis
    4
4 more recorded rows
  • humoral immune defect
    4
  • hypersensitivity myocarditis
    3
  • throat irritation
    3
  • fibrin d dimer increased
    3

recorded 2026-06-24 · last checked 2026-09-04

Where it is registered
Identifiers, relations and other names

The exact record

ChEMBL id
CHEMBL4650491
CAS number
2430046-03-8
Also called
Cx-024414, Moderna covid-19 vaccine rna, Mrna-1273, Spikevax mrna, Tak-919, bnt162b2, covid-19 vaccine, covid-19 vaccine moderna, moderna, moderna covid-19 vaccine, moderna mrna-1273, moderna mrna-1273 vaccine
Development code
M-1273
Trade name
Spikevax (previously covid-19 vaccine moderna)
Sources (4)

Sources

ChEMBL 37 — CC BY-SA 3.0 Unported · ClinicalTrials.gov — US Government work · Open Targets 26.06 — CC0 · mixed register set; per-register licences in docs/specs/corpus-20k-sources.md

How these records are assembled · Which registers were checked

Index-quality checks
  • identity passed: no open identity hold
  • required summary fields resolved: 4 required field(s) not terminal: Why people use it, Best-supported result, Biggest unanswered question, Human evidence
  • public claims reviewed: 0 reviewed claim(s); drafts are never rendered
  • source coverage passed: 4 source rows
  • no critical contamination: no quarantine open
  • canonical metadata passed: slug and display name present
  • no raw internal fields: enforced by the copy-contract test over the rendered page

This is a record of evidence. It is not medical advice, and it does not say this substance suits you. Nothing here says any substance on RNAWiki is appropriate for a child.