Pneumovax 23

Pneumovax® 23 solution for injection in pre-filled syringe

Manufacturer: Merck Sharp & Dohme (UK) Limited
Label last updated: 05 Jun 2026
Source: Official SmPC ↗

Twenty-three serotype pneumococcal vaccine for the 65+ programme and at-risk groups from age 2. The older, unconjugated polysaccharide type, so it works poorly in children under 2 and its protection fades.

49 findings, each with the section of the label it comes from.

Ingredients and materials

25 micrograms of each of 23 pneumococcal polysaccharide serotypes per 0.5 ml dose: 1, 2, 3, 4, 5, 6B, 7F, 8, 9N, 9V, 10A, 11A, 12F, 14, 15B, 17F, 18C, 19F, 19A, 20, 22F, 23F and 33Fs.2
Prepared from purified pneumococcal capsular polysaccharide antigens, with no carrier protein and no aluminium adjuvants.5.1
Excipients: phenol (a preservative), sodium chloride, water for injectionss.6.1
Declared essentially sodium-free, less than 1 mmol (23 mg) per doses.4.4
The 23 serotypes included account for approximately 90 per cent of invasive pneumococcal disease typess.5.1

Manufacture, storage and handling

Shelf life 28 monthss.6.3
Store at 2C to 8C, do not freezes.6.4
Supplied as a clear colourless solution, ready to use with no dilution or reconstitutions.6.6
Intramuscular or subcutaneous injection; a single 0.5 ml doses.4.2
Should never be injected intravascularly, with precautions to keep the needle out of a blood vessel, and should not be injected intradermally because that route is associated with increased local reactionss.4.4
Discard if extraneous particulate matter or discolouration is seens.6.6
Must not be mixed with other medicinal products; no compatibility studies exists.6.2
Revaccination at an interval of less than three years is not recommended because of an increased risk of adverse reactionss.4.2
There are very limited clinical data on giving more than two dosess.4.2

Safety findings

Not recommended for children under 2 years of age because the safety and efficacy have not been established and the antibody response may be poors.4.2
Polysaccharide antigens induce antibodies mainly by T-cell-independent mechanisms and so elicit poor or inconsistent antibody responses in children under 2s.5.1
The only listed contraindication is hypersensitivity to the active substance or to any of the excipientss.4.3
Use should be delayed in any significant febrile illness, other active infection, or when a systemic reaction would pose a significant risk, except where the delay might involve even greater risks.4.4
In patients who are immunosuppressed from an underlying condition or treatment such as cancer chemotherapy or radiation therapy, the expected antibody response may not be obtained after a first or second dose, so they may not be as well protected as immunocompetent peoples.4.4
Vaccination during chemotherapy or radiation therapy should be avoided, and the vaccine should not be given any sooner than three months after the completion of such therapy, with a longer delay possibly appropriate after intensive or prolonged treatments.4.2
It is recommended the vaccine be given at least two weeks before an elective splenectomy or the start of chemotherapy or other immunosuppressive treatments.4.2
Vaccination may not result in complete protection in all recipientss.4.4
Required prophylactic antibiotic therapy against pneumococcal infection should not be stopped after vaccinations.4.4
The vaccine may not be effective in preventing infection resulting from a basilar skull fracture or from external communication with cerebrospinal fluids.4.4
People at especially increased risk, such as asplenic patients and those who have had immunosuppressive therapy, should be advised about the possible need for early antimicrobial treatment in the event of a severe sudden febrile illnesss.4.4
In a study of 629 adults aged 65 and over and 379 aged 50 to 64, rates of injection site and systemic reactions in the older group were not higher than the younger group, but the label notes that in general elderly individuals may not tolerate medical interventions as well, and a higher frequency or greater severity in some older individuals cannot be ruled outs.4.4
Rates of local reactions, and some systemic reactions in those aged 65 and over, are higher after revaccination than after primary vaccination when three to five years have elapsed between dosess.4.2
Very common reactions: injection site redness, induration, pain, soreness, swelling and warmths.4.8
Listed as rare: extensive swelling of the vaccinated limb, described as cellulitis-like reactions with a short onset from vaccinations.4.8
Post-marketing reports at frequency not known include haemolytic anaemia in patients who have had other haematological disorders, leukocytosis, lymphadenitis, lymphadenopathy, thrombocytopenia in patients with stabilised idiopathic thrombocytopenic purpura, anaphylactoid reactions, angioneurotic oedema, serum sickness, febrile convulsions, Guillain-Barre syndrome, paraesthesia, radiculoneuropathy, nausea, vomiting, rash, urticaria, arthralgia, arthritis, myalgia, asthenia, chills, fever, decreased injected limb mobility, injection site necrosis, malaise, peripheral oedema in the injected extremity and increased C-reactive proteins.4.8
In a study of 102 individuals including 25 aged 2 to 17, the type and severity of reactions in children were comparable to adults, but the proportion reporting injection site and systemic reactions was higher in the 2 to 17 groups.4.8
Pregnancy: animal studies are insufficient with respect to reproductive toxicity, and the vaccine should not be used during pregnancy unless clearly necessary, with the potential benefit justifying any potential risk to the foetuss.4.6
Breastfeeding: it is unknown whether the vaccine is excreted in human milk, and caution should be exercised when it is given to a nursing mothers.4.6
Fertility: the vaccine has not been evaluated in fertility studiess.4.6
Overdose: not applicables.4.9

Evidence and claims

The efficacy of polyvalent pneumococcal polysaccharide vaccine was established for pneumococcal pneumonia and bacteraemia in randomised controlled trials conducted among novice gold miners in South Africa: 76.1 per cent with a 6-valent vaccine and 91.7 per cent with a 12-valent preparations.5.1
In trials in the populations for which the vaccine is indicated, vaccine effectiveness was reported as 50 to 70 per cent, for example in people with diabetes mellitus, chronic cardiac or pulmonary disease, and anatomic asplenias.5.1
'The concentration of anti-capsular antibody required to protect against pneumococcal infection caused by any specific capsular type has not been established's.5.1
Most people aged 2 and over, 85 to 95 per cent, respond by making antibody to most or all of the 23 polysaccharidess.5.1
Antibodies can be detected by the third week after vaccination but may decline as soon as 3 to 5 years later, with a more rapid decline in some groups such as children and the elderlys.5.1
On revaccination, geometric mean antibody concentrations at day 30 were lower than after primary vaccination, with ratios of 0.60 to 0.94 in the over-65 group and 0.62 to 0.97 in the 50 to 64 group. 'The clinical relevance of the lower antibody responses observed on revaccination compared to primary vaccination is not known's.5.1
In a double-blind trial of 473 adults aged 60 and over, immune responses to ZOSTAVAX (shingles vaccine) given at the same time were not similar to when it was given separatelys.5.1
However, in a US cohort study of 35,025 adults aged 60 and over, no increased risk of shingles was observed with concomitant administration, with an adjusted hazard ratio of 1.04 (confidence interval 0.92 to 1.16) over a median follow-up of 4.7 yearss.5.1
Preclinical safety: 'No preclinical safety testing was performed using the vaccine's.5.3

Document and licensing

Marketing authorisation holder: Merck Sharp & Dohme (UK) Limited, Londons.7
First authorised 27 April 2015s.9
Text last revised 12 May 2026; the document carries a 2026 copyright notice for Merck & Co., Rahway, New Jerseys.10
The evidence base for the original efficacy claim is a trial in novice gold miners, which the label states openlys.5.1
Suspected reactions are reported through the MHRA Yellow Card schemes.4.8

Every line above is a summary of a statement in the manufacturer's own label, with the section number it comes from. Nothing has been added from any other source. The full list of flagged sentences is below, as it came out of the document.

Listed ingredients

Section 2 - qualitative and quantitative composition source ↗

The 0.5 mL dose of vaccine contains 25 micrograms of each of the following 23 pneumococcal polysaccharide serotypes: 1, 2, 3, 4, 5, 6B, 7F, 8, 9N, 9V, 10A, 11A, 12F, 14, 15B, 17F, 18C, 19F, 19A, 20, 22F, 23F, 33F.
 Excipient(s) with known effect 
 Sodium less than 1 mmol (23 mg) per dosage unit.
 For the full list of excipients, see section 6.1.

Other ingredients (excipients)

Section 6.1 source ↗

PhenolA preservative that stops bacteria growing. Also used in some antiseptics. It is toxic in large amounts, which is why only trace quantities are used.
Sodium chlorideSalt. Used to keep the liquid at the same saltiness as the body.
Water for injectionsPurified water to the standard used for injected medicines. It is the liquid the other ingredients are dissolved in.

Audit trail: every flagged sentence in the document (23)

These are the sentences the mechanical filter pulled out, in the document's own words, grouped by section. They are what the briefing above was built from, kept here so you can check nothing was left out. Some are fragments and some are technical, which is why the briefing exists.

4.2 Posology and method of administration

Pneumococcal polysaccharide vaccine is not recommended for use in children below 2 years of age as the safety and efficacy of the vaccine have not been established and the antibody response may be poor.

Section 4.2 Posology and method of administration source ↗
In plain English
- not been established - There is not yet enough evidence to state a conclusion.
- not recommended - The manufacturer advises against it. This is weaker than 'contraindicated', which means it must not be given.
- efficacy - How well it works in the controlled conditions of a trial.
Efficacy, effectiveness and endpointsNo data / not studiedNot recommended, contraindicated or restricted matched: efficacy, have not been established, not recommended
Vaccination during chemotherapy or radiation therapy should be avoided.

Section 4.2 Posology and method of administration source ↗

Not recommended, contraindicated or restricted matched: should be avoided
Revaccination at an interval of less than three years is not recommended because of an increased risk of adverse reactions.

Section 4.2 Posology and method of administration source ↗
In plain English
- not recommended - The manufacturer advises against it. This is weaker than 'contraindicated', which means it must not be given.
Not recommended, contraindicated or restricted matched: not recommended
For selected populations (e.g., asplenics) who are known to be at high risk of fatal pneumococcal infections, revaccination at three years may be considered.

Section 4.2 Posology and method of administration source ↗

Rare or very rare serious events matched: fatal

4.4 Special warnings and precautions for use

Pneumococcal polysaccharide vaccine should never be injected intravascularly, and precautions should be taken to make sure the needle does not enter a blood vessel.

Section 4.4 Special warnings and precautions for use source ↗

Animal, human or cell-line derived material matched: blood
For patients receiving immunosuppressive therapy, the time to recovery of the immune response varies with the illness and the therapy.

Section 4.4 Special warnings and precautions for use source ↗
In plain English
- immunosuppressive - A medicine or treatment that dampens the immune system.
Efficacy, effectiveness and endpoints matched: immune response
Required prophylactic antibiotic therapy against pneumococcal infection should not be stopped after pneumococcal vaccination.

Section 4.4 Special warnings and precautions for use source ↗

Trace residues and process chemicals matched: antibiotic

4.6 Fertility, pregnancy and lactation

Animal studies are insufficient with respect to effects on reproductive toxicity (see section 5.3).

Section 4.6 Fertility, pregnancy and lactation source ↗
In plain English
- reproductive toxicity - Harm to fertility or to an unborn baby.
- insufficient - Not enough to draw a conclusion from.
Limited, insufficient or inconclusive matched: insufficient
The vaccine should not be used during pregnancy unless clearly necessary (the potential benefit must justify any potential risk to the foetus).

Section 4.6 Fertility, pregnancy and lactation source ↗
In plain English
- should not be used - The label says the product should not be given in this situation.
Not recommended, contraindicated or restricted matched: should not be used
It is unknown whether this vaccine is excreted in human milk.

Section 4.6 Fertility, pregnancy and lactation source ↗

No data / not studied matched: is unknown
The vaccine has not been evaluated in fertility studies.

Section 4.6 Fertility, pregnancy and lactation source ↗
In plain English
- has not been evaluated - It has not been tested or measured in this group or situation.
No data / not studied matched: has not been evaluated

4.8 Undesirable effects

The table below summarises the frequencies of the adverse reactions that were reported with Pneumococcal polysaccharide vaccine in clinical trials and/or post marketing surveillance, using the following convention: very common (≥1/10); common (≥1/100 to <1/10); uncommon (≥1/1,000 to <1/100); rare (≥1/10,000 to <1/1,000); very rare (<1/10,000); not known (cannot be estimated from available data).

Section 4.8 Undesirable effects source ↗
In plain English
- very common - In the label's frequency scale, this means it happened in more than 1 in 10 people studied.
- very rare - In the label's frequency scale, this means it happened in up to 1 in 10,000 people. Often these are reports sent in after a vaccine is in use rather than findings from a formal study.
- not known - The label's lowest band: the number of cases is too small, or the reporting too patchy, to work out how often it happens.
No data / not studiedRare or very rare serious events matched: not known, very rare

5.1 Pharmacodynamic properties

A ≥2-fold increase in antibody level following vaccination was associated with efficacy in clinical trials of polyvalent pneumococcal polysaccharide vaccines.

Section 5.1 Pharmacodynamic properties source ↗
In plain English
- efficacy - How well it works in the controlled conditions of a trial.
Efficacy, effectiveness and endpoints matched: efficacy
However, the concentration of anti-capsular antibody required to protect against pneumococcal infection caused by any specific capsular type has not been established.

Section 5.1 Pharmacodynamic properties source ↗
In plain English
- not been established - There is not yet enough evidence to state a conclusion.
No data / not studied matched: not been established
o In the primary and revaccination groups the geometric mean antibody levels for each serotype increased from pre- to post-vaccination.

Section 5.1 Pharmacodynamic properties source ↗
In plain English
- geometric mean - An average used for antibody levels, because those vary over a huge range.
Efficacy, effectiveness and endpoints matched: geometric mean
o The ratios in geometric mean antibody concentrations by serotype at day 30 between those who were revaccinated and those who were given primary vaccination ranged from 0.60-0.94 in the ≥65 years group and from 0.62-0.97 for the group aged between 50-64 years.

Section 5.1 Pharmacodynamic properties source ↗
In plain English
- geometric mean - An average used for antibody levels, because those vary over a huge range.
Efficacy, effectiveness and endpoints matched: geometric mean
The clinical relevance of the lower antibody responses observed on revaccination compared to primary vaccination is not known.

Section 5.1 Pharmacodynamic properties source ↗
In plain English
- not known - The label's lowest band: the number of cases is too small, or the reporting too patchy, to work out how often it happens.
No data / not studied matched: not known
However in a US effectiveness cohort study of 35,025 adults ≥60 years old, no increased risk of herpes zoster (HZ) was observed in individuals who received ZOSTAVAX and 23-valent pneumococcal polysaccharide vaccine concomitantly (N=16,532) as compared to individuals receiving ZOSTAVAX one month to one year after 23-valent pneumococcal polysaccharide vaccine (N=18,493) in routine practice.

Section 5.1 Pharmacodynamic properties source ↗
In plain English
- effectiveness - How well it works in ordinary use in the real world.
Efficacy, effectiveness and endpoints matched: effectiveness
The data do not indicate that concomitant administration of the two vaccines alters the effectiveness of ZOSTAVAX.

Section 5.1 Pharmacodynamic properties source ↗
In plain English
- effectiveness - How well it works in ordinary use in the real world.
Efficacy, effectiveness and endpoints matched: effectiveness
The efficacy of polyvalent Pneumococcal polysaccharide vaccine was established for pneumococcal pneumonia and bacteraemia in randomised controlled trials that were conducted among novice gold miners in South Africa.

Section 5.1 Pharmacodynamic properties source ↗
In plain English
- randomised - A trial where people are assigned to groups by chance.
- efficacy - How well it works in the controlled conditions of a trial.
Efficacy, effectiveness and endpoints matched: efficacy
The protective efficacy against pneumococcal pneumonia, the primary endpoint in these studies, was 76.1% with a 6-valent vaccine and 91.7% with a 12-valent preparation.

Section 5.1 Pharmacodynamic properties source ↗
In plain English
- efficacy - How well it works in the controlled conditions of a trial.
Efficacy, effectiveness and endpoints matched: efficacy
In trials conducted in populations for which the vaccine is indicated (see section 4.1), vaccine effectiveness was reported to be 50 to 70% (e.g., persons with diabetes mellitus, chronic cardiac or pulmonary disease, and anatomic asplenia).

Section 5.1 Pharmacodynamic properties source ↗
In plain English
- effectiveness - How well it works in ordinary use in the real world.
Efficacy, effectiveness and endpoints matched: effectiveness
Decreasing estimates of effectiveness have been reported with increasing interval after vaccination, particularly among the very elderly (persons aged ≥85 years).

Section 5.1 Pharmacodynamic properties source ↗
In plain English
- effectiveness - How well it works in ordinary use in the real world.
Efficacy, effectiveness and endpoints matched: effectiveness

Read the whole document at the source ↗