A randomized placebo-controlled trial of acetaminophen for prevention of post-vaccination fever in infants

Common Selfcare Indications of Pain Medications in Children

Pain has a multifaceted impact on individuals worldwide, affecting their physical functioning, emotional well-being, and quality of life. Children (age < 18 years) have a high prevalence of conditions associated with pain, such as toothache, headache, earache, sore throat, and respiratory tract infections, many of which may be accompanied by fever. Globally, the pharmacologic treatment of pain in pediatric patients is limited largely to nonopioid analgesics, and dosing must account for differences in age, weight, metabolism, and risk of adverse effects. This narrative review summarizes the findings of a literature search on the pediatric indications, dosing approaches, dosing guidelines, and pharmacokinetics of paracetamol and ibuprofen, which are common pain medications available globally for self-care use in children. The review also discusses the risks and benefits associated with these agents. The current roles of paracetamol and ibuprofen in the symptomatic management of coronavirus disease 2019 (COVID-19) infection and in the management of post-COVID-19 immunization symptoms in children are also discussed. Therefore, while a very large amount of data over several decades is available for paracetamol and ibuprofen, an urgent need exists for well-designed studies of these medications for the management of pain and fever in pediatric patients with COVID-19 to ensure optimal relief with minimal toxicity.

COVID-19 vaccines in patients with cancer: immunogenicity, efficacy and safety

Patients with cancer have a higher risk of severe coronavirus disease (COVID-19) and associated mortality than the general population. Owing to this increased risk, patients with cancer have been prioritized for COVID-19 vaccination globally, for both primary and booster vaccinations. However, given that these patients were not included in the pivotal clinical trials, considerable uncertainty remains regarding vaccine efficacy, and the extent of humoral and cellular immune responses in these patients, as well as the risks of vaccine-related adverse events. In this Review, we summarize the current knowledge generated in studies conducted since COVID-19 vaccines first became available. We also highlight critical points that might affect vaccine efficacy in patients with cancer in the future.

A Survey of Immunization Practices in Patients With Congenital Heart Disease

Background

Congenital heart disease, the most common congenital anomaly, often presents in neonates. Because of perceived risks, health care providers may consider deferring immunizations in this population. We sought to understand the perceived risk of immunizations in those providing health care to children with particular heart conditions.

Methods

A survey, which included 6 hypothetical scenarios assessing immunization recommendations, was distributed internationally to relevant health care providers, and responses were compared between the different scenarios.

Results

Majority of responses (n = 142) were from paediatric cardiologists (n = 98; 69%) and nurse practitioners (n = 27; 19%) located in the United States (n = 77; 54%) or Canada (n = 53; 37%) working in academic teaching hospitals (n = 133; 93.7%). Most favoured vaccinations (n = 107; 75.4%) and less likely to proceed with the first immunization in infants with structural heart disease compared with channelopathy (risk ratio: 0.80, confidence interval: 0.73-0.87; P < 0.001). Only 40% would proceed with immunization as normal in an infant with manifest Brugada type I electrocardiogram. Special precautions after the immunization included longer duration of observation (19%) and administering prophylactic antipyretic medication (92%).

Conclusions

Respondents were 20% more likely to defer immunizations in the presence of treatable structural heart disease as compared with channelopathy despite the lack of evidence supporting deferring immunizations in children with structural heart disease. Most were cautious in their response to the scenario involving Brugada syndrome, indicating awareness of the risk of haemodynamic instability in the event of a fever. The majority of respondents still strongly recommend immunizations in this population as the benefits outweigh the potential for adverse events.

Cross-sectional Retrospective Study on Paracetamol Post Infants' Vaccination in Malaysia

INTRODUCTION

Practice of dispensing paracetamol (PCM) in post infants' vaccination remains debatable in Malaysia as the administration of PCM postvaccination in infants was found to cause the vaccine to be less effective, thus requiring appropriate regulation measures.

OBJECTIVE

This research aimed to investigate the prevalence of adverse events following immunization (AEFI) with/without PCM to be prescribed post infants' vaccination in Malaysia (possible associated factors: age, types and stages of vaccination, concomitant vaccines and drugs, and/vitamins).

MATERIALS AND METHODS

A retrospective cross-sectional study was conducted from 2011 to 2017. The AEFI was extracted from Quests 2, 3, and 3+ System of National Pharmaceutical Regulatory Agency (NPRA). The population of vaccinated infants was obtained from the Ministry of Health (MOH) Malaysia official website. The AEFI data were further categorized into (i) AEFI with possibility for PCM to be prescribed, and (ii) AEFI with no possibility for PCM to be prescribed. The data were analyzed using Microsoft Excel 2013, Portland, USA simple and multiple logistic regression tests, Statistical Package for the Social Sciences (SPSS) software programme, version 22.0 (IBM), New York, USA.

RESULT

Various AEFI cases (359 infants) were reported. DTaP/Hib/IPV and measles-mumps-rubella (MMR) showed higher prevalence of AEFI with/without PCM to be prescribed post infants' vaccination cases per 100,000 population (2.07 and 2.21, respectively) than other types of vaccinations. DTaP/Hib/IPV (2 months) vaccination showed the highest value (3.00) among other age groups. Backward elimination presented DTaP/Hib/IPV (3-4 months) (95%CI; 0.231, 0.899%; P = 0.023) was the possible associated factor. Hepatitis B (1-5 months), DTaP/Hib/IPV (3-4 months), DTaP/Hib/IPV (5-12 months), concomitant vaccines as well as concomitant drugs and/ vitamins were the identified potential cofounders.

CONCLUSION

Prescribing and dispensing of PCM post infants' vaccination may be confined to DTaP/Hib/IPV (2-4 months) and 12 months MMR groups.

Definite bacterial infection in recently vaccinated febrile infants

AIM

There is insufficient evidence regarding the best approach to evaluating recently vaccinated (RV) infants presenting to the paediatric emergency department with fever. The aim of the present study is to determine the prevalence of bacterial infections in infants presenting with fever within 72 h after vaccination.

METHODS

We retrospectively reviewed the electronic medical record of infants aged between 6 and 12 weeks who presented with a fever ≥38°C to the emergency department from January 2016 to December 2018. Febrile infants who were vaccinated within 72 h prior to their emergency department presentation were matched to those who had not received their vaccines in the previous 72 h. Definite serious bacterial infection was diagnosed based on culture results.

RESULTS

A total of 198 infants (age: 9 ± 1.84 weeks, male: 119 (60.1%)) were enrolled in this study. Overall, 60 of 138 (30.3%) had received their vaccines within the previous 72 h. The prevalence of bacterial infection in RV infants was 5% compared to 15.2% in non-RV infants (P = 0.056). Interestingly, all vaccinated infants who had proven bacterial infection presented to the emergency department with fever within 24 h of vaccination, and all bacterial infections in that group were urinary tract infections.

CONCLUSIONS

The prevalence of bacterial infection among non-RV febrile infants is relatively higher than those RV. However, fever should not be attributed only to the vaccinations, and all febrile RV infants should be carefully evaluated, and at least urine testing should be performed regardless of the time of vaccination.

Postvaccination Fever Response Rates in Children Derived Using the Fever Coach Mobile App: A Retrospective Observational Study

BACKGROUND

Postvaccination fever is a mild adverse event that naturally improves without complications, but is highly prevalent and can be accompanied by febrile convulsions in some cases. These adverse effects may cause parents to delay or avoid vaccinating their children.

OBJECTIVE

This study aimed to identify postvaccination fever patterns and the ability of antipyretics to affect changes in these patterns from data collected from a mobile app named Fever Coach.

METHODS

Data provided by parents of feverish children derived from a mobile app, Fever Coach, were used to identify postvaccination fever patterns according to vaccinations and the use of antipyretic drugs. We selected single vaccination records that contained five or more body temperature readings performed within 48 hours of vaccination, and we analyzed postvaccination fever onset, offset, duration, and maximum body temperature. Through observing the postvaccination fever response to vaccination, we identified the effects of antipyretic drugs on postvaccination fever onset, offset, and duration times; the extent of fever; and the rate of decline. We also performed logistic regression analysis to determine demographic variables (age, weight, and sex) involved in relatively high fevers (body temperature ≥39°C).

RESULTS

The total number of Fever Coach users was 25,037, with 3834 users having entered single vaccination records, including 4448 vaccinations and 55,783 body temperature records. Most records were obtained from children receiving the following vaccinations: pneumococcus (n=2069); Japanese encephalitis (n=911); influenza (n=669); diphtheria, tetanus, and pertussis (n=403); and hepatitis A (n=252). According to the 4448 vaccination records, 3427 (77.05%) children had taken antipyretic drugs, and 3238 (89.15%) children took antibiotics at body temperatures above 38°C. The number of children taking antipyretics at a body temperature of 38°C was more than four times that of those taking antipyretics at 37.9°C (307 vs 67 cases). The number of instances in which this temperature threshold was reached was more than four times greater than the number when the temperature was 37.9°C. A comparative analysis of antipyretic and nonantipyretic cases showed there was no difference in onset time; however, offset and duration times were significantly shorter in nonantipyretic cases than in antipyretic cases (P<.001). In nonantipyretic cases, offset times and duration times were 9.9 and 10.1 hours shorter, respectively, than in antipyretic cases. Body temperatures also decreased faster in nonantipyretic cases. Influenza vaccine-associated fevers lasted relatively longer, whereas pneumococcus vaccine-associated fevers were relatively short-lived.

CONCLUSIONS

These findings suggest that postvaccination fever has its own fever pattern, which is dependent on vaccine type and the presence of antipyretic drugs, and that postvaccination temperature monitoring may ease fever phobia and reduce the unnecessary use of antipyretics in medical care.

The Relevancy of paracetamol and Breastfeeding Post Infant Vaccination: A Systematic Review

Background: Paracetamol may be used as an antipyretic agent for the treatment of fever, as well as an analgesic in the treatment of mild to moderate pain post-vaccination in infants. The use of paracetamol during fever may be or may not be recommended since it may alter the natural human body immune response, although it may reduce pain. Objectives: The aims of this study are to describe the effectiveness of breastfeeding in reducing pain and paracetamol in reducing fever and pain post infant vaccination. Methods: Data sources and study selection was conducted by electronic searching of six databases. Manual reference checks of all articles on paracetamol and breastfeeding post infant vaccination published in the English language between 1978 and 2017. Two levels of screening were used on 9614 citations, which include screening of abstracts and titles followed by full text screening. The data synthesis were tabulated into study characteristics, quality, and effects. Results: Systematic review of breastfeeding included three studies from 9614 database searches found significant benefit from breastfeeding in pain scores and the duration of crying, as well as behavioural changes. None of the studies stated the detriment of breastfeeding before, during, and after immunization. Systematic review of paracetamol effectiveness included four studies from 1177 database searches found significant benefit from prophylaxis paracetamol in fever, one study found significant benefit from prophylaxis paracetamol in fussiness, and one study's results were found to be not significant. Two studies on evaluating the safety of prophylactic paracetamol in 2009 found that antibody responses to several antigens were significantly reduced, and the other study in 1988 found that antibody titres to DTP bacteria of placebo and PCM did not differ significantly. Conclusions: The relevancy of giving paracetamol post all types of vaccination may be questionable. Breastfeeding before, during, and after immunization are recommended for pain reduction and are proven effective. Further research is required in deciding if paracetamol is to be of rational use following infant immunization.

The effect of antipyretics on immune response and fever following receipt of inactivated influenza vaccine in young children

BACKGROUND

Antipyretics reduce fever following childhood vaccinations; after inactivated influenza vaccine (IIV) they might ameliorate fever and thereby decrease febrile seizure risk, but also possibly blunt the immune response. We assessed the effect of antipyretics on immune responses and fever following IIV in children ages 6 through 47 months.

METHODS

Over the course of three seasons, one hundred forty-two children, receiving either a single or the first of 2 recommended doses of IIV, were randomized to receive either oral acetaminophen suspension (n = 59) or placebo (n = 59) (double-blinded) or ibuprofen (n = 24) (open-label) immediately following IIV and every 4-8 h thereafter for 24 h. Blood samples were obtained at enrollment and 4 weeks following the last recommended IIV dose. Responses to IIV were assessed by hemagglutination inhibition assay (HAI). Seroprotection was defined as an HAI titer ≥1:40 and seroconversion as a titer ≥1:40 if baseline titer <1:10 or four-fold rise if baseline titer ≥1:10. Participants were monitored for fever and other solicited symptoms on the day of and day following IIV.

RESULTS

Significant differences in seroconversion and post-vaccination seroprotection were not observed between children included in the different antipyretic groups and the placebo group for the vaccine antigens included in IIV over the course of the studies. Frequencies of solicited symptoms, including fever, were similar between treatment groups and the placebo group.

CONCLUSIONS

Significant blunting of the immune response was not observed when antipyretics were administered to young children receiving IIV. Studies with larger sample sizes are needed to definitively establish the effect of antipyretics on IIV immunogenicity.

Effect of antipyretic analgesics on immune responses to vaccination

While antipyretic analgesics are widely used to ameliorate vaccine adverse reactions, their use has been associated with blunted vaccine immune responses. Our objective was to review literature evaluating the effect of antipyretic analgesics on vaccine immune responses and to highlight potential underlying mechanisms. Observational studies reporting on antipyretic use around the time of immunization concluded that their use did not affect antibody responses. Only few randomized clinical trials demonstrated blunted antibody response of unknown clinical significance. This effect has only been noted following primary vaccination with novel antigens and disappears following booster immunization. The mechanism by which antipyretic analgesics reduce antibody response remains unclear and not fully explained by COX enzyme inhibition. Recent work has focused on the involvement of nuclear and subcellular signaling pathways. More detailed immunological investigations and a systems biology approach are needed to precisely define the impact and mechanism of antipyretic effects on vaccine immune responses.

Effects of Administering Prophylactic Acetaminophen on Short-term Complications of Vaccination in 6-month-old Infants

BACKGROUND

We aimed to assess the effects of administering prophylactic acetaminophen on short-term complications of vaccination in 6-month-old infants admitted to a private pediatric clinic in Rasht (Iran) during 2002-2013.

METHODS

This quasi-experimental study was conducted on 696, infants aged 6-month-old admitted to a pediatric clinic in Rasht before vaccination during 2002-2013. Overall, 31 infants were excluded during the course of the study. While prophylactic acetaminophen was administered in 322 participants (intervention group), 343 infants (control group) received acetaminophen after vaccination. Data were collected by a checklist including complications such as fever, drowsiness, anorexia, seizure, long and excessive crying, mood change, pain, and wound at the site of injection, abscess, induration, limb swelling, and erythema. The time of occurrence of each complication was also recorded. Data were analyzed by Chi-square test in SPSS 16.0. P < 0.05 was considered significant.

RESULTS

Six hundred sixty-five participants (49.6% boy) were assessed in this study. The intervention and control groups had no significant difference in terms of sex distribution (P = 0.53). Short-term complications occurred in 45% of the infants. The most common complications were erythema (24.4%), induration (19.9%), and low-grade fever (16.1%). There was a significant relation between administering prophylactic acetaminophen and the incidence of low-grade fever (P = 0.01), induration (P = 0.01), and anorexia (P = 0.03).

CONCLUSIONS

Our findings indicated the efficacy of prophylactic acetaminophen in reducing postvaccination complications in a population of Iranian infants. According to our findings, further research is required to determine the preferred dose and time of administering acetaminophen.

The effect of prophylactic antipyretic administration on post-vaccination adverse reactions and antibody response in children: a systematic review

Background

Prophylactic antipyretic administration decreases the post-vaccination adverse reactions. Recent study finds that they may also decrease the antibody responses to several vaccine antigens. This systematic review aimed to assess the evidence for a relationship between prophylactic antipyretic administration, post-vaccination adverse events, and antibody response in children.

Methods

A systematic search of major databases including MEDLINE and EMBASE was carried out till March 2014. Randomized controlled trials (RCTs) comparing prophylactic antipyretic treatment versus placebo post-vaccination in children ≤6 years of age were included. Two reviewers independently applied eligibility criteria, assessed the studies for methodological quality, and extracted data [PROSPERO registration: CRD42014009717].

Results

Of 2579 citations retrieved, a total of 13 RCTs including 5077 children were included in the review. Prophylactic antipyretic administration significantly reduced the febrile reactions (≥38.0°C) after primary and booster vaccinations. Though there were statistically significant differences in the antibody responses between the two groups, the prophylactic PCM group had what would be considered protective levels of antibodies to all of the antigens given after the primary and booster vaccinations. No significant difference in the nasopharyngeal carriage rates (short-term and long-term) of H. influenzae or S. pneumoniae serotypes was found between the prophylactic and no prophylactic PCM group. There was a significant reduction in the local and systemic symptoms after primary, but not booster vaccinations.

Conclusions

Though prophylactic antipyretic administration leads to relief of the local and systemic symptoms after primary vaccinations, there is a reduction in antibody responses to some vaccine antigens without any effect on the nasopharyngeal carriage rates of S. pneumoniae & H. influenza serotypes. Future trials and surveillance programs should also aim at assessing the effectiveness of programs where prophylactic administration of PCM is given. The timing of administration of antipyretics should be discussed with the parents after explaining the benefits & risks.

Early phase clinical trials with human immunodeficiency virus-1 and malaria vectored vaccines in The Gambia: frontline challenges in study design and implementation

Human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) and malaria are among the most important infectious diseases in developing countries. Existing control strategies are unlikely to curtail these diseases in the absence of efficacious vaccines. Testing of HIV and malaria vaccines candidates start with early phase trials that are increasingly being conducted in developing countries where the burden of the diseases is high. Unique challenges, which affect planning and implementation of vaccine trials according to internationally accepted standards have thus been identified. In this review, we highlight specific challenges encountered during two early phase trials of novel HIV-1 and malaria vectored vaccine candidates conducted in The Gambia and how some of these issues were pragmatically addressed. We hope our experience will be useful for key study personnel involved in day-to-day running of similar clinical trials. It may also guide future design and implementation of vaccine trials in resource-constrained settings.

A phase 2 randomized controlled trial of a multicomponent meningococcal serogroup B vaccine (I)

The novel meningococcal serogroup B vaccine (4CMenB, Bexsero(®)), recently approved in Europe and Australia, may soon be included in routine infant immunization schedules, subject to guidance from national or regional recommending bodies. In the development of 4CMenB and consistent with other newly introduced vaccines, clinical studies have shown concomitant administration with routine infant vaccines induces an incremental increase in some reactions, including fever. As this may hinder acceptability, we examined the impact of prophylactic paracetamol on the occurrence of fever and other solicited reactions, as well as the immune responses to study vaccines, in a prospectively designed study. 4CMenB was administered as a 4-dose series at 2, 3, 4, and 12 months of age concomitantly with routine infant vaccines: DTaP-HBV-IPV/Hib and PCV7, with or without prophylactic paracetamol; a third group received MenC vaccine. Immune responses to 4CMenB were not decreased by the use of paracetamol prophylaxis and there were no clinically relevant effects on immune responses to routine vaccines. Occurrence of fever was higher in infants co-administered with 4CMenB compared with those given MenC vaccine, but was significantly decreased by prophylactic paracetamol, as were other solicited reactions to vaccination, both local and systemic. Co-administration of 4CMenB had an acceptable tolerability profile, with no withdrawals due to vaccination-related adverse events. Inclusion of 4CMenB in routine infant immunization schedules will be a major advance in the control of meningococcal disease, and our study indicates that by using paracetamol prophylaxis, post-vaccination reactions are reduced without clinically relevant negative consequences on vaccine immunogenicity.

An open-label randomized clinical trial of prophylactic paracetamol coadministered with 7-valent pneumococcal conjugate vaccine and hexavalent diphtheria toxoid, tetanus toxoid, 3-component acellular pertussis, hepatitis B, inactivated poliovirus, and Haemophilus influenzae type b vaccine

BACKGROUND

In two clinical trials, low-grade fever was observed more frequently after coadministration than after separate administration of two recommended routine pediatric vaccines. Since fever is an important issue with vaccine tolerability, we performed this open-label study on the efficacy and safety of prophylactic use of paracetamol (acetaminophen, Benuron®) in children administered routine 7-valent pneumococcal conjugate vaccine (PCV-7) coadministered with hexavalent vaccine (diphtheria-tetanus-acellular pertussis-hepatitis B, poliovirus, Haemophilus influenzae type b vaccine [DTPa-HBV-IPV/Hib]) in Germany.

METHODS

Healthy infants (N = 301) who received a 3-dose infant series of PCV-7 and DTPa-HBV-IPV/Hib plus a toddler dose were randomly assigned 1:1 to prophylactic paracetamol (125 mg or 250 mg suppositories, based on body weight) at vaccination, and at 6-8 hour intervals thereafter, or a control group that received no paracetamol. Rectal temperature and local and other systemic reactions were measured for 4 days post vaccination; adverse events were collected throughout the study.

RESULTS

In the intent-to-treat population, paracetamol reduced the incidence of fever ≥38°C, but this reduction was only significant for the infant series, with computed efficacy of 43.0% (95% confidence interval [CI]: 17.4, 61.2), and not significant after the toddler dose (efficacy 15.9%; 95% CI: -19.9, 41.3); results were similar in the per protocol (PP) population. Fever >39°C was rare during the infant series, such that there were too few cases for assessment. After the toddler dose, paracetamol effectively reduced fever >39°C, reaching statistical significance in the PP population only (efficacy 79%; 95% CI: 3.9, 97.7). Paracetamol also reduced reactogenicity, but there were few significant differences between groups after any dose. No vaccine-related serious adverse events were reported.

CONCLUSIONS

Paracetamol effectively prevented fever and other reactions, mainly during the infant series. However, as events were generally mild and of no concern in either group our data support current recommendations to administer paracetamol to treat symptoms only and not for routine prophylaxis.

TRIAL REGISTRATION

NCT00294294.

Rectal paracetamol in newborn infants after assisted vaginal delivery may increase pain response

OBJECTIVE

To assess the efficacy of paracetamol (acetaminophen) for neonatal pain relief.

STUDY DESIGN

Randomized, double-blind placebo-controlled trial in 3 Swiss university hospitals. Term and near-term infants (n = 123) delivered by forceps or vacuum were randomized to receive 2 suppositories with paracetamol (60/80/100 mg in infants <3000 g/3000-4000 g/>4000 g birth weight) or placebo at 2 and 8 hours of life. Pain and discomfort during the first 24 hours was assessed by the échelle de douleur et d'inconfort du nouveau né [neonatal pain and discomfort scale] score. The response to the subsequent heel prick for metabolic screening at days 2-3 of life was investigated by the Bernese Pain Scale for Neonates (BPSN).

RESULTS

The échelle de douleur et d'inconfort du nouveau né [neonatal pain and discomfort scale] pain scale ratings after assisted vaginal delivery were low and declined within 4 hours of life (P < .01) irrespective of paracetamol administration. At 2-3 days of life, BPSN scores after heel prick were significantly higher in infants who had received paracetamol, compared with controls, both when BPSN were scored by nurses at the bedside (median [IQR] 4 [2-7] vs 2 [0-5], P = .017) or off-site from videos (4 [2-8] vs 2 [1-7], P = .04). Thirty-five of 62 (57%) infants treated with paracetamol cried after heel prick, compared with 25 of 61 (41%) controls (P = .086).

CONCLUSIONS

Infants born by assisted vaginal delivery have low pain scores in the immediate period after birth. Paracetamol given to newborns soon after birth may aggravate a subsequent stress response.