Effects of measles-containing vaccination in children with severe underlying neurologic disease

BackgroundMeasles outbreaks pose significant risk for those unvaccinated.Patients and methodsMeasles-containing vaccine was offered to unvaccinated children with severe neurologic diseases during a measles outbreak. Vaccination adverse events were reported by parents 30 days following vaccination. Long term effects were evaluated 12 months post vaccination.ResultsTwenty-seven children were vaccinated (36 doses given). Half of parents (51.8%) reported no adverse events following immunization. Adverse events included afebrile seizures (6/36), fever alone (5/36) and febrile seizures (5/36). Two children required hospitalization. Quadrivalent measles-containing vaccine combined with varicella was associated with febrile seizures (p = 0.04). No child needed adjustment of the anti-epileptic treatment or exhibited developmental regression.ConclusionIn a series of children with prior severe neurologic disease, the safety-tolerability profile of vaccines containing a measles vaccine component suggests that vaccination is justified. Main side effect was seizure aggravation in children with known epileptic disease.     

Revaccination outcomes of children with vaccine proximate seizures

BackgroundSeizures, whether febrile or afebrile, occurring within 14 days following vaccination can be considered as vaccine proximate seizures (VPSs). While the attributable risk and clinical severity of first febrile VPS is well known, the risk and clinical outcomes of VPS recurrence is less well defined.MethodsWe conducted a retrospective review of revaccination management and outcomes in children who experienced a VPS as their first seizure seen in Australian Specialist Immunisation Clinics between 2013 and 2017. Vaccination outcomes were compared between children who had a VPS as their only seizure (VPS only) and children who had further non-vaccine proximate seizures following their initial VPS (VPS+) prior to review at the clinic.ResultsWe identified 119 children with a VPS as their first seizure, of which 61 (51%) went on to have other seizures (VPS+). Children with VPS+ were more likely to present at a younger age (6.2 vs 12.5 months, P = 0.03), with afebrile seizures (42.6% vs 15.5%, P = 0.002) compared to VPS only children. VPS recurrence on revaccination was uncommon in both groups, but more common in VPS+ children (12.5% vs 2.4%, P = 0.07). Having an epilepsy diagnosis, specifically Dravet syndrome, was associated with VPS recurrence (P < 0.001). Of the four children with Dravet syndrome who had VPS recurrence, all had status epilepticus following revaccination.ConclusionIn children who presented with a single VPS as their only seizure, VPS recurrence on revaccination was uncommon. Children who had multiple non-vaccine proximate seizures following their initial VPS (VPS+) were more likely to present with afebrile VPS, at a younger age and have a VPS recurrence with vaccination. In these children, particularly those aged < 12 months, assessment and investigation for diagnosis of Dravet syndrome should be considered and additional precautions for revaccination undertaken as they are at highest risk of VPS recurrence.     

Enhanced surveillance for adverse events following immunization during the 2019 typhoid conjugate vaccine campaign in Harare,Zimbabwe

BackgroundDuring February 25–March 4, 2019, Zimbabwe’s Ministry of Health and Child Care conducted an emergency campaign using 342,000 doses of typhoid conjugate vaccine (TCV) targeting individuals 6 months–15 years of age in eight high-risk suburbs of Harare and up to 45 years of age in one suburb of Harare. The campaign represented the first use of TCV in Africa outside of clinical trials.MethodsThree methods were used to capture adverse events during the campaign and for 42 days following the last dose administered: (1) active surveillance in two Harare hospitals, (2) national passive surveillance, and (3) a post-campaign coverage survey.ResultsThirty-nine adverse events were identified during active surveillance, including 19 seizure cases (16 were febrile), 16 hypersensitivity cases, 1 thrombocytopenia case, 1 anaphylaxis case, and two cases with two conditions. Only 21 (54%) of 39 patients were hospitalized and 38 recovered without sequelae. Attack rates per 100,000 TCV doses administered were highest for seizures (6.27) and hypersensitivity (5.02). Only 6 adverse events were reported through passive surveillance by facilities other than the two active surveillance hospitals. A total of 177 (10%) of 1,817 vaccinees surveyed reported experiencing an adverse event during the post-campaign coverage survey, of which 25 (14%) sought care.ConclusionsIn line with previous evaluations of TCV, enhanced adverse event monitoring during an emergency campaign supports the safety of TCV. The majority of reported events were minor or resulted in recovery without long-term sequelae. Attack rates for seizures and hypersensitivity were low compared with previous active surveillance studies conducted in Kenya and Burkina Faso. Strengthening adverse event monitoring in Zimbabwe and establishing background rates of conditions of interest in the general population may improve future safety monitoring during new vaccine introductions.     

Validation of febrile seizures identified in the Sentinel Post-Licensure Rapid Immunization Safety Monitoring Program

BackgroundThe Sentinel Initiative was established in 2008 to monitor the safety of FDA-regulated medical products. We evaluated the positive predictive value (PPV) of ICD-9 codes for post-vaccination febrile seizures to identify optimal algorithms for use in post-market safety surveillance.MethodsWe identified ICD-9 diagnosis codes for fever and seizures in the emergency department or inpatient setting after vaccinations of interest from July 1, 2010 to June 30, 2011. Medical record review was conducted to verify febrile seizure events.ResultsOf 216 potential febrile seizures identified with one or more seizure codes (the broadest algorithm), 152 were chart-confirmed (i.e., documentation of fever within 24 h of seizure or clinician diagnosis of febrile seizure; PPV 70%, 95% CI 64, 76%). Two codes specific for febrile seizures produced the highest PPV (PPV 91%, 95% CI 85, 95%) and accounted for 140 confirmed febrile seizures. In the absence of febrile seizure codes, other seizure codes yielded much lower PPVs, regardless of the presence of fever codes.ConclusionsOur results indicate that ICD-9 diagnosis codes in the inpatient and emergency department settings have high predictive value for identifying febrile seizures within the Sentinel Distributed Database. While the PPV of the algorithm based on any diagnosis code for seizure is moderate, the algorithm limited to febrile seizure codes has a high PPV (>90%) and captures the vast majority of confirmed cases identified by the broadest algorithm, suggesting that the narrower algorithm limited to febrile seizure codes may be preferred.     

Signal identification and evaluation for risk of febrile seizures in children following trivalent inactivated influenza vaccine in the Vaccine Safety Datalink Project, 2010-2011

In fall 2010 in the southern hemisphere, an increased risk of febrile seizures was noted in young children in Australia in the 24 h after receipt of trivalent inactivated influenza vaccine (TIV) manufactured by CSL Biotherapies. Although the CSL TIV vaccine was not recommended for use in young children in the US, during the 2010-2011 influenza season near real-time surveillance was conducted for febrile seizures in the 0-1 days following first dose TIV in a cohort of 206,174 vaccinated children ages 6 through 59 months in the Vaccine Safety Datalink Project. On a weekly basis, surveillance was conducted with the primary approach of a self-controlled risk interval design and the secondary approach of a current vs. historical vaccinee design. Sequential statistical methods were employed to account for repeated analyses of accumulating data. Signals for seizures based on computerized data were identified in mid November 2010 using a current vs. historical design and in late December 2010 using a self-controlled risk interval design. Further signal evaluation was conducted with chart-confirmed febrile seizure cases using only data from the primary approach (i.e. self-controlled risk interval design). The magnitude of the incidence rate ratio and risk difference comparing risk of seizures in the 0-1 days vs. 14-20 days following TIV differed by receipt of concomitant 13-valent pneumococcal conjugate vaccine (PCV13). Among children 6-59 months of age, the incidence rate ratio (IRR) for TIV adjusted for concomitant PCV13 was 2.4 (95% CI 1.2, 4.7) while the IRR for PCV13 adjusted for concomitant TIV was 2.5 (95% CI 1.3, 4.7). The IRR for concomitant TIV and PCV13 was 5.9 (95% CI 3.1, 11.3). Risk difference estimates varied by age due to the varying baseline risk for seizures in young children, with the highest estimates occurring at 16 months (12.5 per 100,000 doses for TIV without concomitant PCV13, 13.7 per 100,000 doses for PCV13 without concomitant TIV, and 44.9 per 100,000 doses for concomitant TIV and PCV13) and the lowest estimates occurring at 59 months (1.1 per 100,000 doses for TIV without concomitant PCV13, 1.2 per 100,000 doses for PCV13 without concomitant TIV, and 4.0 per 100,000 doses for concomitant TIV and PCV13). Incidence rate ratio and risk difference estimates were lower for children receiving TIV without concomitant PCV13 or PCV13 without concomitant TIV. Because of the importance of preventing influenza and pneumococcal infections and associated complications, our findings should be placed in a benefit-risk framework to ensure that population health benefits are maximized.     

The risk of febrile seizures following influenza and 13-valent pneumococcal conjugate vaccines

BackgroundEvidence on the risk of febrile seizures after inactivated influenza vaccine (IIV) and 13-valent pneumococcal conjugate vaccine (PCV13) is mixed. In the FDA-sponsored Sentinel Initiative, we examined risk of febrile seizures after IIV and PCV13 in children 6–23 months of age during the 2013–14 and 2014–15 influenza seasons.MethodsUsing claims data and a self-controlled risk interval design, we compared the febrile seizure rate in a risk interval (0–1 days) versus control interval (14–20 days). In exploratory analyses, we assessed whether the effect of IIV was modified by concomitant PCV13 administration.ResultsAdjusted for age, calendar time and concomitant administration of the other vaccine, the incidence rate ratio (IRR) for risk of febrile seizures following IIV was 1.12 (95% CI 0.80, 1.56) and following PCV13 was 1.80 (95% CI 1.29, 2.52). The attributable risk for febrile seizures following PCV13 ranged from 0.33 to 5.16 per 100,000 doses by week of age.The age and calendar-time adjusted IRR comparing exposed to unexposed time was numerically larger for concomitant IIV and PCV13 (IRR 2.80, 95% CI 1.63, 4.83), as compared to PCV13 without concomitant IIV (IRR 1.54, 95% CI 1.04, 2.28), and the IRR for IIV without concomitant PCV13 suggested no independent effects of IIV (IRR 0.94, 95% CI 0.63, 1.42). Taken together, this suggests a possible interaction between IIV and PCV13, though our study was not sufficiently powered to provide a precise estimate of the interaction.ConclusionsWe found an elevated risk of febrile seizures after PCV13 vaccine but not after IIV. The risk of febrile seizures after PCV13 is low compared to the overall risk in this population of children, and the risk should be interpreted in the context of the importance of preventing pneumococcal infections.     

Risk factors for the occurrence of recurrent convulsions following an initial febrile convulsion]

The results of a follow up study of 155 Dutch children who visited the emergency room of an urban paediatric hospital after experiencing their first febrile seizure are presented. Median follow up time was 38 months (range 27-60). Of these 155 initially untreated children 58 (37%) suffered at least one, 47 (30%) at least two and 27 (17%) at least three recurrent seizures. The recurrence hazard after any seizure was highest in the first six months, and dropped markedly after 6 months without seizures. The effect of the various postulated risk factors on the occurrence of any recurrent seizure and three or more recurrences was assessed. A first degree family history of febrile or nonfebrile seizures appears to be a predictor of multiple recurrences; an age of at least 30 months and a temperature of 40.0 degrees C or higher at the initial seizure are associated with a decreased risk. Several factors act together on the risk of recurrent seizures, sometimes in opposite directions. By considering the action of all relevant factors (age at onset, family history and features of the initial febrile seizure) subgroups of children with one year seizure recurrence rates as low as 15% and as high as 48% were identified.     

Febrile seizures: current concepts concerning prognosis and clinical management

Febrile seizures are a common problem in young children. Most febrile seizures are benign in nature, although a small percentage of children may develop recurring febrile seizures or afebrile seizures. The approach to the management of this disorder varies widely from specialty to specialty despite the recent publication of studies that provide for rational treatment of febrile seizures. Most children do not need any treatment after a first simple febrile seizure. In certain children who are at risk for recurrent febrile seizures, rectal anticonvulsants should be considered for acute, short-term management. Long-term anticonvulsants should be reserved for patients who are unable to use rectal anticonvulsants or who have significant risk factors for the development of afebrile seizures.     

Prevalence of febrile seizures in Dutch schoolchildren

During a scheduled visit to the school physician, the number of children with a history of febrile seizures was determined in 3570 children attending primary schools in the suburban area of the city of Rotterdam. At the age of 6 years, 140 had experienced at least one febrile seizure (3.9%, 95% confidence interval 3.3% to 4.5%). Of these, 19 (14%) had experienced a recurrent seizure during the same febrile illness. Recurrent seizures in subsequent fever episodes occurred in 26%. The median age at onset was 18 months. One-third of the children had visited the hospital directly after the seizure, and 6% had used anticonvulsant drugs for at least 6 months. Of all the children, 5.4% had a positive first-degree family history of febrile seizures. Children with a positive family history were at a 4.5-fold increased risk of experiencing febrile seizures. Since in this study a generally accepted definition of febrile seizures was used, the estimated prevalence in Dutch school-children may well be compared with prevalence rates found in the United States and Great Britain.     

Prevalence of febrile seizures in Dutch schoolchildren

Summary. During a scheduled visit to the school physician, the number of children with a history of febrile seizures was determined in 3570 children attending primary schools in the suburban area of the city of Rotterdam. At the age of 6 years, 140 had experienced at least one febrile seizure (3.9%, 95% confidence interval 3.3% to4.5%). Of these, 19 (14%) had experienced a recurrent seizure during the same febrile illness. Recurrent seizures in subsequent fever episodes occurred in 26%. The median age at onset was 18 months. One-third of the children had visited the hospital directly after the seizure, and 6% had used anticonvulsant drugs for at least 6 months. Of all the children, 5.4% had a positive first-degree family history of febrile seizures. Children with a positive family history were at a 4.5-fold increased risk of experiencing febrile seizures. Since in this study a generally accepted definition of febrile seizures was used, the estimated prevalence in Dutch schoolchildren may well be compared with prevalence rates found in the United States and Great Britain.     

New Onset (Incidence) of Epilepsy and Seizures in Nursing Home Residents

ObjectiveThe point prevalence of epilepsy is high in nursing homes (NH), but the incidence of epilepsy after admission is unknown. This study was done to determine the incidence of epilepsy/seizure (epi/sz) comorbid with other conditions in older adult NH residents.DesignRetrospective evaluation of Minimum Data Set records to identify new onset epi/sz in NH residents.Setting and ParticipantsFive cross-sectional cohorts of all residents in any Medicare/Medicaid certified NH in the United States on July 15 of each year 2003-2007.MeasuresEpi/sz was identified by International Classification of Diseases, Ninth Revision codes (345.xx or 780.39) or check box on the Minimum Data Set. Those with no such code on admission and with 1 to 3 plus years of follow-up (n = 3,609,422) were followed through 2007 or end of stay.ResultsOverall incidence of epi/sz was 16.42/1000 patient years (PY). Incidence was highest in the first year after admission and declined thereafter. There were more women (n = 2,523,951) than men (n = 1,089,631), but men had a higher incidence (21.17/1000PY) compared with women (14.81/1000PY). Although the 65?74 years of age cohort included fewer residents (n = 594,722) compared with the age 85 years + cohort (n = 1,520,167), the younger residents had the highest incidence (28.53/1000 PY) compared with the oldest, 10.22/1000 PY for the age 85+ years cohort. The highest incidences were among those with brain tumor (122.55/1000PY), followed by head injury (45.66/1000PY). Overall, 714,340 had a diagnosis of stroke, and incidence was 27.52/1000PY. Those with none of selected risk factors had an overall incidence of 12.45/1000PY.Conclusions and ImplicationsThe incidence of epi/sz in older individuals after admission to a NH is high. There is a need to develop practice approaches to best manage this large cohort. There does not appear to be a uniform approach to managing new onset epilepsy in NHs at this time. Studies to develop evidence for practice guidelines are needed.     

Characteristics and incidence of vaccine adverse events after Bacille Calmette–Guérin vaccination: A national surveillance study in Japan from 2013 to 2017

BackgroundJapan amended the recommended age for the Bacille Calmette–Guérin (BCG) vaccination to less than 6 months after 2005, but subsequently amended the recommended age to 5–8 months (latest amendment, <1 year) in April 2013 due to the increasing incidence of BCG-associated osteitis/osteomyelitis since 2005.MethodsWe collected data on BCG-associated vaccine adverse events (VAEs) in the population aged <1 year between April 2013 and March 2017. The incidence of BCG-associated VAE was analyzed using census and vaccine coverage data from the government website. We compared the incidence of VAEs in patients vaccinated at less than 6 months with those vaccinated at 6 months or older.ResultsAmong the 581 BCG-associated VAEs recorded during the study period, 354 (61%) were male, and the average age at vaccination was 5.7 months. The incidence of VAEs per million population aged <1 year at vaccination was highest for suppurative lymphadenitis (63.7), followed by skin lesions (38.4), and BCG-associated osteitis/osteomyelitis (3.1). Disseminated BCG and anaphylaxis were rare (1.1 and 1.6%, respectively). The incidence of VAEs in the population vaccinated at <6 months of age was higher for BCG-associated osteitis/osteomyelitis (3.8) and disseminated BCG (1.3) than in the population vaccinated at ≥6 months.ConclusionsThe population vaccinated at <6 months of age was more likely to develop BCG-associated osteitis/osteomyelitis than the population vaccinated at ≥6 months of age, indicating that the change in the recommended vaccination age in 2013 might have contributed to the subsequent decrease in the incidence of BCG-associated osteitis/osteomyelitis.     

Risk factors of febrile seizures among preschool children in Alexandria

The study design was a case control study to identify the risk factors of febrile seizures. Total sample of 28 children, their ages ranging from 12 to 60 months, with febrile seizure were matched with control group of 60 children of the same age group with fever without seizure. The peak age of first febrile seizure was between 6 and 12 months. The significant risk factors were upper respiratory tract infection (p < 0.05), family history of febrile seizures (p < 0.0001). Prematurity (p < 0.005), problems during gestation (p < 0.005), family history of epilepsy (p < 0.005) and problem during labour (p < 0.0005).     

Febrile seizures and epilepsy: the contributions of epidemiology

In the past, febrile seizures were considered to be a sign of epilepsy, a disorder characterised by recurrent unprovoked seizures. Currently, febrile seizures are considered to be a benign seizure syndrome that is distinct from epilepsy. This distinction has been possible largely because of the epidemiological evidence which is presented here in the form of a two-part argument. If febrile seizures are epilepsy one might expect that: (1) following a first febrile seizure, the risk of a second febrile seizure should be similar to the risk of an unprovoked seizure (in fact, the risk of a recurrent febrile seizure is approximately 34%, whereas the risk of an unprovoked seizure after having had a febrile seizure is approximately 2% to 3%); (2) the factors that predict recurrent febrile seizures should also predict subsequent unprovoked seizures. From the available literature, young age at the time of the first febrile seizure and a family history of febrile seizures predict recurrent febrile seizures, but do not predict subsequent unprovoked seizures. By contrast, a family history of epilepsy, complex febrile seizures and neurological abnormality are associated with an increased risk of subsequent epilepsy but are not consistently associated with the risk of a recurrent febrile seizure.     

The long-term risk of epilepsy after febrile seizures in susceptible subgroups

A family history of seizures, preexisting brain damage, or birth complications may modify the long-term risk of epilepsy after febrile seizures. The authors evaluated the association between febrile seizures and epilepsy in a population-based cohort of 1.54 million persons born in Denmark (1978-2002), including 49,857 persons with febrile seizures and 16,481 persons with epilepsy. Overall, for children with febrile seizures compared with those without such seizures, the rate ratio for epilepsy was 5.43 (95% confidence interval: 5.19, 5.69). The risk remained high during the entire follow-up but was particularly high shortly after the first febrile seizure, especially in children who experienced early (<1 year of age) or late (>3 years of age) onset of febrile seizures. At 23 years of follow-up, the overall cumulative incidence of epilepsy after febrile seizures was 6.9% (95% confidence interval: 6.5, 7.3). In conclusion, persons with a history of febrile seizures had a higher rate of epilepsy that lasted into adult life, but less than 7 percent of children with febrile seizures developed epilepsy during 23 years of follow-up. The risk was higher for those who had a family history of epilepsy, cerebral palsy, or low Apgar scores at 5 minutes.     

Incidence of acute respiratory tract infections (2006–2015) and influenza (2006–2013) among French armed forces

ObjectivesWe aimed to assess the incidence of respiratory tract infections in military settings between 2006 and 2015.Patients and methodsWe performed a retrospective epidemiological study of the entire military population from 2006 to 2015. Comprehensive data was collected from all medical centers, operational medical units, naval services, and army training hospitals and provided by the epidemiological surveillance of the armies.ResultsThe annual average population of the study was 331,394 soldiers. For acute respiratory tract infections (2006–2015), 22,818 cases were reported in metropolitan France, 3,211 cases in French overseas territories, 1,595 cases in the French Navy, and 1,318 cases in external military operations for a total of 28,942 cases. For influenza (2006–2013), 934 cases were reported in metropolitan France, 101 cases in French overseas territories, and 23 cases in external operations, for a total of 1,058 cases. The mean incidence rate of acute respiratory tract infections expressed as case number per 1,000 person-years (PY) was 8.7 PY (95% CI [8.6–8.8]) with an exceptional increased incidence rate in 2009 (25.9 PY, 95% CI [25.4–26.4]). The mean incidence rate of influenza was 0.35 PY (95% CI [0.33–0.37]) with a peak incidence rate of 1.9 PY in 2009.ConclusionAcute respiratory tract infections are at the forefront of infectious episodes in the French armies. Although not necessarily severe, current prevention measures are not enough to reduce the incidence threshold of these infections and need to be improved.     

Risk of febrile seizure after measles–mumps–rubella–varicella vaccine: A systematic review and meta-analysis

BackgroundConsidering the febrile seizure rate, there is no longer a clear preference for use of measles–mumps–rubella–varicella (MMRV) vaccine over separate measles–mumps–rubella (MMR) and varicella (V) vaccine. This work was undertaken to assess the risk of febrile seizure after MMRV vaccine in children.MethodsWe searched PubMed, Embase, BIOSIS Previews, Scopus, Web of Science, Cochrane Library and other databases through 12 December 2014. Meta-analysis was conducted using R version 3.1.2 and Stata version 12.0.ResultsA total of thirty-nine studies were included. Thirty-one published or unpublished clinical trials involving about 40,000 subjects did not show significant differences in incidence of febrile seizure or vaccine related febrile seizure between MMRV and MMR with or without varicella vaccine after any doses, in the risk windows of 0–28, 0–42 or 0–56 days and 7–10 days. In addition, these studies showed that the receipt of concomitant use of MMRV and other pediatric vaccines was not a significant predictor of febrile seizure. Eight post-marketing observations involving more than 3,200,000 subjects were included. No evidence suggested elevated risk of febrile seizure associated with MMRV vaccine among children aged 4–6 years old during 7–10 days or 0–42 days after vaccination. However, an approximately 2-fold increase in risk of seizure or febrile seizure during 7–10 days or 5–12 days after MMRV vaccination was found among children aged 10–24 months, although the highest incidence of seizure was still lower than 2.95‰.ConclusionsFirst MMRV vaccine dose in children aged 10–24 months was associated with an elevated risk of seizure or febrile seizure. Further post-marketing restudies based on more rigorous study design are needed to confirm the findings.     

Adverse events following immunization with the live-attenuated recombinant Japanese encephalitis vaccine (IMOJEV®) in Taiwan, 2017–18

BackgroundJapanese encephalitis (JE) is a significant public health concern in the Asia-Pacific region, with a case-fatality rate of around 20% for those who develop encephalitis. Mouse-brain derived vaccines against JE have been used in the publicly funded national immunization program (NIP) in Taiwan since 1968. They were replaced with a live-attenuated recombinant vaccine (JE-CV, IMOJEV®) in May 2017. We assessed reports of adverse events (AE) following the introduction of JE-CV into the Taiwan NIP to characterize its post-licensure safety profile.MethodsAEs reported between 1 May 2017 and 31 December 2018 post vaccination with JE-CV were extracted from the National Adverse Drug Reactions (ADR) Reporting System, a passive surveillance system run by the Taiwan Food and Drug Administration. The report rates were calculated based on the number of doses distributed by the manufacturer during the assessment period.ResultsThere were 51 AEs reported among 30 subjects (12 girls and 18 boys; mean age 25 months), with a reporting rate of 4.7 AEs per 100,000 doses distributed. The AEs occurred after a median of.1-day post vaccination. Eight subjects had received concomitant vaccination with another vaccines. There were four serious AEs reported: febrile seizure, acute renal failure, viral respiratory tract infection, and injection site cellulitis. None of these serious AEs were classified as being causally related to JE-CV vaccination.ConclusionThese post-licensure AE surveillance data confirm the favorable safety profile of JE-CV.     

Analysis of safety data in children after receiving two doses of ProQuad® (MMRV)

BackgroundIn randomized clinical studies, over 11,800 children, 12 months to 6 years of age, were administered ProQuad^®, a combination measles, mumps, rubella, and varicella vaccine (MMRV). This paper describes the safety following a 2-dose regimen of MMRV administered to children in the second year of life.MethodsSafety data from five clinical studies were combined for all children who were scheduled to receive two doses of MMRV ∼3–6 months apart. All vaccinated children were followed for safety following each dose of MMRV.ResultsOf 3112 children who received a first dose of MMRV, 2780 (89.3%) received a second dose of MMRV. Overall, 70.5% and 57.7% of children reported ≥1 adverse experiences following first and second doses of MMRV, respectively. Injection-site redness was statistically significantly higher postdose 2 than postdose 1, while injection-site pain/tenderness was statistically significantly higher postdose 1 compared to postdose 2. Rashes were statistically significantly lower postdose 2 compared to postdose 1. Ten febrile seizures (8 postdose 1, 2 postdose 2) were reported following MMRV vaccination. The incidence of febrile seizures postdose 1 of MMRV was 0.26% (8/3019) compared to 0.07% (2/2695) postdose 2 of MMRV.ConclusionsAdministration of two doses of MMRV has an acceptable safety profile in children 12 to 23 months of age. There is a small increase in the risk of febrile seizures following the first dose of MMRV as compared to the component vaccines, but the risk for any individual child is relatively low.     

Reduction in invasive meningococcal disease in Queensland: a success for immunisation

Since 2003, the Australian government has funded a conjugate serogroup C meningococcal vaccine for those aged over 1 year and born since 1 January 1984. This summary of the epidemiology of invasive meningococcal disease (IMD) in Queensland assesses the effect that the vaccination program has had on IMD notifications. In Queensland, IMD cases are notified to the Notifiable Conditions System by clinicians and laboratories. Additional surveillance data are collected by population health units from relatives of the case, the case and medical practitioners. In 2005, Queensland recorded its lowest number of cases and lowest incidence of IMD since statewide surveillance began. This remained low in 2006. The serogroup C rate in Queensland also declined to its lowest in 2006. The pattern of age specific incidence remains similar, though rates are lower in all but those aged less than 12 months. However, Indigenous rates are still twice non-Indigenous rates. The case fatality rate for IMD (all serogroups) has declined, possibly due to the reduced incidence of serogroup C and septicaemia cases. The program appears to have mostly achieved its aims of: reducing illness and death in the population at highest risk; inducing immunity in those who are vaccinated; and reducing the incidence of disease. However, there is considerable natural fluctuation in the rates of IMD and continued surveillance will be needed to monitor trends.