Injection Pain PreventionNCT07455305
The Effect of Simultaneous Versus Sequential Intramuscular Vaccine Injections on Pain Levels in Infants
A study testing Simultaneous injection and Sequential injection in people with Injection Pain Prevention and Injection Pain, run by Istanbul University - Cerrahpasa at 1 site in Turkey (Türkiye).
Trial summary
This study was designed as a randomized controlled trial comparing simultaneous and sequential administration of intramuscular vaccines in infants. Read more about this study
- Who is it for?
- Ages Up to 12 monthsHealthy volunteers can take part
- Conditions the study is for
- Injection Pain Prevention, Injection Pain
- What is being tested?
- Simultaneous injection and Sequential injection
- Type of treatment
- Vaccines, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 110 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Sep 2021to 15 Nov 2021
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Up to 12 months
- All sexes
- Healthy volunteers accepted
- Child
Who may be able to join
- The following criteria were determined: the child was ordered to receive two of the routine childhood IM vaccines (hepatitis B, quintuple combination vaccine, pneumococcal vaccine), the parents were willing to participate in the study, the child had not received painkillers in the last 6 hours, and the child did not have mental and motor retardation.
Who cannot join
- It was determined that the child should be 1 year of age or older, the vaccines other than the quintuple mixed vaccine, Pneumococcal vaccine and Hepatitis B vaccine should have been ordered by the physician.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: The Effect of Simultaneous Versus Sequential Intramuscular Vaccine Injections on Pain Levels in Infants: a Randomized Controlled Trial
This study was designed as a randomized controlled trial comparing simultaneous and sequential administration of intramuscular vaccines in infants.
Read the detailed description
The study was carried out in the pediatric outpatient vaccination clinic of a private hospital in Istanbul, Türkiye, between 1 September and 15 November 2021.
Infants were eligible if they were younger than 12 months, required two routine intramuscular vaccines during the same visit, and were accompanied by a parent or legal guardian able to provide informed consent.
Infants were excluded if they had received analgesics within six hours prior to vaccination, received vaccines other than hepatitis B, pentavalent combination vaccine (DTaP-IPV/Hib), or pneumococcal conjugate vaccine, or had known neurological, developmental, or motor impairments.
Infants were randomly assigned in a 1:1 ratio to either the simultaneous injection group or the sequential injection group using computer-generated randomization (www.randomizer.org). Allocation was completed prior to the vaccination procedure.
A total of 150 infants were assessed for eligibility; 40 did not meet inclusion criteria. The final sample included 110 infants (55 per group). No participants were lost to follow-up.
- Conditions
- Injection Pain Prevention, Injection Pain
- Being tested
- Simultaneous injection, Sequential injection
- Keywords
- sequential injection, simultaneous injection
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Simultaneous injectionOther
Two trained pediatric nurses administered the vaccines simultaneously into different thighs (vastus lateralis muscles) following a coordinated countdown.
Sequential injectionOther
A single nurse administered the two vaccines consecutively into different thighs. A pause of approximately 10-15 seconds between injections allowed the infant to settle.
| Study group | Role | What they receive |
|---|---|---|
| Simultaneous injection group | Experimental | Two trained pediatric nurses administered the vaccines simultaneously into different thighs (vastus lateralis muscles) following a coordinated countdown. Receives: Other: Simultaneous injection |
| Sequential injection group | Other | A single nurse administered the two vaccines consecutively into different thighs. A pause of approximately 10-15 seconds between injections allowed the infant to settle.
Vaccinations were performed individually in a quiet room to prevent distraction or distress from other children. Infants were positioned on an examination stretcher with the thigh exposed. Receives: Other: Sequential injection |
What is being measured
The primary outcome is the main question the study is designed to answer.
Pain was assessed using the FLACC
The scale has 5 behavioral assessment categories (facial expression, leg movement, activity, crying, consolability). Each category consists of three items and is scored between 0 and 2 points. The total scale score ranges from 0 to10, with higher scores indicating greater pain intensity.
Measured: Time Frame: Baseline; During injection (periprocedural); Immediately after injection (within 1 minute)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Mar 2026
- Study start1 Sep 2021
- Primary completion15 Nov 2021
- Study completion15 Nov 2021
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Injection Pain PreventionStudies of the same condition, open and under way.
- More trials run by Istanbul University - CerrahpasaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Supportive care
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 110 participants (actual)
Sponsor and investigators
- Lead sponsor
- Istanbul University - Cerrahpasa
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Sevil Inal, Istanbul University - Cerrahpasa
- Investigators
- Sevil Inal, Study director, Istanbul University - Cerrahpasa
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07455305
- Sponsor's protocol ID
- IUCerrahpasaRCT
- Status last verified
- Mar 2026
- First submitted
- 25 Feb 2026
- Last updated
- 6 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Institutional policy does not allow
Study at a glance
From the registry record, last updated by the sponsor on 6 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect of Simultaneous Versus Sequential Intramuscular Vaccine Injections on Pain Levels in Infants: a Randomized Controlled Trial
- ClinicalTrials.gov ID
- NCT07455305
- Acronym / sponsor ID
- IUCerrahpasaRCT
- Conditions
- Injection Pain Prevention, Injection Pain
- Keywords
- sequential injection, simultaneous injection
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 110 participants (actual)
- Lead sponsor
- Istanbul University - CerrahpasaUniversity, hospital or other
- Study start
- 1 Sep 2021 (actual)
- Primary completion
- 15 Nov 2021 (actual)
- Study completion
- 15 Nov 2021 (actual)
- First posted
- 6 Mar 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study was designed as a randomized controlled trial comparing simultaneous and sequential administration of intramuscular vaccines in infants.
Detailed description
The study was carried out in the pediatric outpatient vaccination clinic of a private hospital in Istanbul, Türkiye, between 1 September and 15 November 2021.
Infants were eligible if they were younger than 12 months, required two routine intramuscular vaccines during the same visit, and were accompanied by a parent or legal guardian able to provide informed consent.
Infants were excluded if they had received analgesics within six hours prior to vaccination, received vaccines other than hepatitis B, pentavalent combination vaccine (DTaP-IPV/Hib), or pneumococcal conjugate vaccine, or had known neurological, developmental, or motor impairments.
Infants were randomly assigned in a 1:1 ratio to either the simultaneous injection group or the sequential injection group using computer-generated randomization (www.randomizer.org). Allocation was completed prior to the vaccination procedure.
A total of 150 infants were assessed for eligibility; 40 did not meet inclusion criteria. The final sample included 110 infants (55 per group). No participants were lost to follow-up.
Study design
- Primary purpose
- Supportive care
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Simultaneous injection group | Experimental | Other: Simultaneous injectionTwo trained pediatric nurses administered the vaccines simultaneously into different thighs (vastus lateralis muscles) following a coordinated countdown. |
| Sequential injection group | Other | Other: Sequential injectionA single nurse administered the two vaccines consecutively into different thighs. A pause of approximately 10-15 seconds between injections allowed the infant to settle. Vaccinations were performed individually in a quiet room to prevent distraction or distress from other children. Infants were positioned on an examination stretcher with the thigh exposed. |
Who may qualify
- Ages
- Up to 12 months
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child
Key inclusion criteria (1 listed)
- The following criteria were determined: the child was ordered to receive two of the routine childhood IM vaccines (hepatitis B, quintuple combination vaccine, pneumococcal vaccine), the parents were willing to participate in the study, the child had not received painkillers in the last 6 hours, and the child did not have mental and motor retardation.
Key exclusion criteria (1 listed)
- It was determined that the child should be 1 year of age or older, the vaccines other than the quintuple mixed vaccine, Pneumococcal vaccine and Hepatitis B vaccine should have been ordered by the physician.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Simultaneous injectionTwo trained pediatric nurses administered the vaccines simultaneously into different thighs (vastus lateralis muscles) following a coordinated countdown. | Other | Simultaneous injection group |
| Sequential injectionA single nurse administered the two vaccines consecutively into different thighs. A pause of approximately 10-15 seconds between injections allowed the infant to settle. | Other | Sequential injection group |
Primary outcome
Pain was assessed using the FLACC
Time frame: Time Frame: Baseline; During injection (periprocedural); Immediately after injection (within 1 minute)
The scale has 5 behavioral assessment categories (facial expression, leg movement, activity, crying, consolability). Each category consists of three items and is scored between 0 and 2 points. The total scale score ranges from 0 to10, with higher scores indicating greater pain intensity.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Mar 2026.
- Individual participant dataSharing planned: No. Institutional policy does not allow
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Sevil Inal study director
Istanbul University - Cerrahpasa
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Simultaneous injection and Sequential injection in people with Injection Pain Prevention and Injection Pain, run by Istanbul University - Cerrahpasa at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 6 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Pain was assessed using the FLACC (time frame: Time Frame: Baseline; During injection (periprocedural); Immediately after injection (within 1 minute)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 Mar 2026.