As much as I support vaccines, I see the short term consequences. Vaccines can be painful. Kids don’t like them, and parents don’t like seeing their children suffer. That this transient pain is the most common consequence of gaining protection from fatal illnesses seems like a fair trade-off to me. But that’s not the case for every parent.
Today’s post isn’t going to focus on the extremes of the anti-vaccination movement. Rather, it’s going to look at ways to make vaccines less painful and more acceptable to children. The pain of vaccines can lead to anxiety, fear, and even nonadherence with vaccination schedules. Fear of needles and injections is not uncommon, it’s estimated that 10% of the population avoids vaccinations for this reason.
The vaccine schedules are intense. Where I live, the public vaccination schedule specifies seventeen injections of six different products over six visits in the first 18 months of life, plus influenza vaccinations and one-offs like H1N1. That’s a lot of visits, and a lot of tears if a child doesn’t handle them well.
In light of what’s known about the prevalence of needle fears, their potential effect on vaccination adherence (that could persist through adult life), and the possible impact on public health because of unvaccinated individuals, it makes sense to do whatever we can to minimize the pain and discomfort of vaccines, increasing their acceptance to children and their parents. But what works? I’ve personally found Smarties (the real ones) and Dora the Explorer stickers are effective distractions and bribes. But I’m not about to call my n=2 trial good science. Nicely, there’s much more evidence to guide our recommendations.
A systematic review and practice guideline has just been published on vaccine pain: Reducing the pain of childhood vaccination: an evidence-based clinical practice guideline. The lead author, Anna Taddio, is a pharmacist and professor at the University of Toronto, and coauthors include large team of academics and health professionals.The guideline is lengthy and detailed, so I’m going to summarize the highlights. There are also some practical handouts for health professionals and parents developed by the authors: links are at the bottom.
Distilling the Evidence
The systematic review looked at both pain and distress (collectively, “pain”) related to vaccine administration. An interdisciplinary team of physician, pharmacists, academics, stakeholders (including parents) were convened, who identified 32 focused clinical questions (later reduced, because of the evidence base). The review didn’t consider post-injection pain and discomfort, which is common yet transient. As pain management is typically based on a “3-P” approach (pharmacologic, physical, and psychological), three systematic reviews and three meta-analyses, one for each domain, were conducted for each clinical question. Evidence was restricted to RCTs. Recommendations were graded based on level of evidence and grade of recommendation according to a standardized format:
Overall, 71 studies involving 8050 children were reviewed. All recommendation were externally reviewed according to a validated process, by vaccination, public health, and medical associations. The study was publicly funded, and disclosed conflicts of interest were minor.
Fourteen clinical questions were answered. The guideline has more detail and specific clinical considerations.
1. Does breastfeeding during vaccination reduce pain at the time of injection?
Yes. Breastfeeding has been shown to provide analgesic effects, possibly through the combination of holding, skin-to-skin contact, the sweetness of the milk, and the process of sucking. To reduce pain, breastfeeding mothers should be encouraged to breastfeed during the vaccination procedure. (Grade I-A)
2. Does administration of a sweet-tasting solution reduce pain at the time of injection?
Yes. Sweet oral solutions provide analgesic effects in infants, reducing signs of pain. Up to 12 months of age, infants who cannot be breastfed during vaccination may be administered a sweet-tasting solution during vaccination (Grade I-A). A simple formula is one packet/cube of sugar in two teaspoons (10 mL) of water. Place in the infant’s mouth with an oral syringe 1-2 minutes before injection. The process is well tolerated, and side effects, like coughing and gagging, are infrequent. Because of conflicting data, there is insufficient evidence to support this strategy in children older than 12 months.
3. Are there pain-related differences between different brands of the same vaccine?
There is only evidence for the MMR vaccine, where differences have been observed between brands. (Grade I-A) Differences may be due to formulation, adjuvants, and pH. Given this is a Canadian-based systematic review, it’s not clear what differences might exist in other countries. Greater knowledge that differences do exist may guide vaccine selection by health authorities. But little choice usually exists at the point of care.
4. Do different body positions results in different pain levels?
The very limited evidence that exists suggests that children are should not be in a supine (lying down) position. (Grade I-E) Sitting upright, or being held, seems preferable. This may be due to anxiety, which could impacts perceived pain. Excessive restraint can increase distress, so holding and support without force is probably preferable.
5. Should slow injection, with aspiration be avoided?
Yes. Intramuscular injections should be given with a rapid injection technique without aspiration (drawing back on the plunger). (Grade I-B). As injection sites do not have large blood vessels, there’s no rationale for aspiration. Slow injection and aspiration may add to the pain due to longer contact time and possible needle wiggle in tissue.
6. When multiple vaccines are to be given in one visit, which first? The most painful, or the least?
This is a common situation. Where differences exist give the most painful vaccine last. (Grade I-B). Based on limited information MMRII and Prevnar appear to be more painful than other vaccines. (This may be specific to Canada. Anyone that administers vaccines routinely will probably know which are more painful.) Giving the more painful vaccine last seems to decrease the overall pain from both injections, based on the results of a single RCT.
7. Does rubbing the skin near the injection site, before and during the procedure, reduce the perception of pain?
Probably, in those 4 years of age and older. Rubbing and stroking the skin may reduce pain. (Grade B-II-1) The mechanism of the analgesia may be the “white noise” created at the site of injection. It’s not clear if this effect is present in young children. The optimal method of rubbing (frequency, intensity, pattern) isn’t known. Rubbing the injection site after injection is thought to increase vaccine reactions and isn’t recommended.
8. Does parental distraction or coaching result in less pain?
There’s insufficient evidence to say. (Grade I-B) Different interventions have been systematically studied, but don’t provide persuasive evidence that it’s effective. This could be due to a number of reasons, including inadequate training or preparation. Given distraction and coaching are cheap and can engage the parent in a formal role, they are reasonable interventions to make. Parent-led distraction is not as effective as clinician- or child-led distraction, however. See the references for a parental tip sheet.
9. Do topical anaestheics reduce injection pain?
Yes. (Grade I-A). Several topical anaesthetics (EMLA, Ametop, Maxilene) are available, and in some countries, without a prescription. They must be applied 20-40 minutes before the procedure. There is no evidence they interfere with vaccine immunogenicity.
10. Does clinician-led distraction result in less pain?
Probably, and is recommended in all age groups. (Grade B-I) See below for a training sheet for health professionals. The same health professional that is administering the vaccine can also administer the distraction, so the intervention does not consume more resources. See the tip sheet in the references for suggested distractions that may be used by clinicians.
11. Do child-led distractions result in less pain?
Yes, in children three years of age or older. (Grade B-I). Child-led distraction effectively reduces pain, however there’s not enough information to determine what’s most effective. See the tip sheets in the references for suggested distractions.
12. Do breathing strategies (deep breathing, blowing) reduce the pain of injection?
Probably. Slow, deep breathing helps relax children and seems to reduce pain. (Grade B-I). Deep breathing and slow blowing may be effective. Using distractions like bubbles, pinwheels or party blowers can serve dual purposes.
13. Do combined interventions (e.g., cognitive AND behavioural techniques) work?
They seem to, based on limited evidence (grade B-I) Combine different interventions in children 3 years of age and older.
14. What about telling the child, “It won’t hurt”?
Not recommended. This has been evaluated, and has not been shown to be effective. (grade D-I)
15. What about cooling sprays or ice packs?
There is insufficient evidence for or against cooling. While vapocoolant sprays are marketed to reduce pain, there’s no persuasive evidence these products are effective in children. Ice packs also may be ineffective. This could be because children perceive coldness as pain.
16. Do simultaneous injections cause less pain than sequential vaccine administration?
Insufficient evidence. Given the the difficulty blinding such an intervention, I’d expect this would be difficult to determine. Given the resource requirements to administer, there seems to be little rationale to consider this approach.
17. Is intramuscular injection less painful than subcutaneous, if the choice is available?
Insufficient evidence. RCTs have provided conflicting evidence. Manufacturer’s prescribing evidence should be followed.
18. What about acetaminophen or ibuprofen before the injection?
Insufficient evidence. There are no RCTs that have evaluated the common practice of giving analgesics in advance of an injection. There is evidence that analgesics do reduce the post-injection side effects of pain. As there’s some data suggestive that this may reduce the immune response to the vaccine itself, the practice is now questioned by some.
Not all arguments against vaccines are are amenable to the simple provision of education or evidence about their efficacy and safety. In some cases, simple interventions may be able shift perceptions of the benefits and consequences.
Compared to what we’d expect for other types of health interventions, the quality of the evidence for some of these recommendations is weak. Yet that shouldn’t stop us from considering them if they’re plausible and easy to implement: There’s little downside risk. By taking steps to reduce vaccine pain we can improve vaccine acceptance, completion of the vaccination schedule, and overall improvements in public health outcomes.
Video based on guidelines: Help Eliminate Pain in Kids
Taddio A, Appleton M, Bortolussi R, Chambers C, Dubey V, Halperin S, Hanrahan A, Ipp M, Lockett D, Macdonald N, Midmer D, Mousmanis P, Palda V, Pielak K, Riddell RP, Rieder M, Scott J, & Shah V (2010). Reducing the pain of childhood vaccination: an evidence-based clinical practice guideline (summary). CMAJ : Canadian Medical Association journal = journal de l’Association medicale canadienne, 182 (18), 1989-95 PMID: 21098067