Post-marketing surveillance of intussusception after Rotarix administration in Afghanistan, 2018-2022

BACKGROUND

In January 2018, Afghanistan introduced the monovalent oral rotavirus vaccine (Rotarix) nationwide, administered as a 2-dose series at six and ten weeks of age. We describe characteristics of intussusception cases and assess potential intussusception risk associated with Rotarix vaccination in Afghan infants.

METHODS

Multi-center prospective active hospital-based surveillance for intussusception was conducted from May 2018 to March 2022 in four sentinel sites in Afghanistan. We applied the Brighton Level 1 criteria for intussusception and verified vaccination status by reviewing vaccine cards. We used the self-controlled case series (SCCS) methodology to compare intussusception incidence in the 1 to 21 days after each dose of Rotarix vaccination against non-risk periods.

RESULTS

A total of 468 intussusception cases were identified in infants under 12 months, with 264 cases aged between 28 and 245 days having confirmed vaccination status contributing to the SCCS analysis. Most case-patients (98 %) required surgery for treatment, and over half (59 %) of those who underwent surgery required intestinal resection. Nineteen (7 %) case-patients died. Eighty-six percent of case-patients received the first dose of Rotarix, and 69 % received the second dose before intussusception symptom onset. There was no increased risk of intussusception in the 1-7 days (relative incidence: 0.9, 95 % CI: 0.1, 7.5), 8-21 days (1.3, 95 % CI: 0.4, 4.2), or 1-21 days (1.1, 95 % CI: 0.4, 3.4) following receipt of the first dose or in the 1-7 days (0.2, 95 % CI: 0.3, 1.8), 8-21 days (0.7, 95 % CI: 0.3, 1.5), or 1-21 days (0.6, 95 % CI: 0.3, 1.2) following the second dose.

CONCLUSION

Rotarix vaccination was not associated with an increased intussusception risk, supporting its continued use in Afghanistan's immunization program. However, there was a high level of death and resection due to intussusception among Afghan infants.

INCLEN Intussusception Surveillance Network Study Group. Risk of intussusception after monovalent rotavirus vaccine (Rotavac) in Indian infants: A self-controlled case series analysis

Background

An association between rotavirus vaccination and intussusception has been documented in post-licensure studies in some countries. We evaluated the risk of intussusception associated with monovalent rotavirus vaccine (Rotavac) administered at 6, 10 and 14 weeks of age in India.

Methods

Active prospective surveillance for intussusception was conducted at 22 hospitals across 16 states from April 2016 through September 2017. Data on demography, clinical features and vaccination were documented. Age-adjusted relative incidence for 1–7, 8–21, and 1–21 days after rotavirus vaccination in children aged 28–364 days at intussusception onset was estimated using the self-controlled case-series (SCCS) method. Only Brighton Collaboration level 1 cases were included.

Results

Out of 670 children aged 2–23 months with intussusception, 311 (46.4%) children were aged 28–364 days with confirmed vaccination status. Out of these, 52 intussusception cases with confirmed receipt of RVV were included in the SCCS analysis. No intussusception case was observed within 21 days of dose 1. Only one case occurred during 8–21 days after the dose 2. Post-dose 3, two cases in 1–7 days and 7 cases during 8–21 days period were observed. There was no increased risk of intussusception during 1–7 days after the doses 1 and 2 (zero cases observed) or dose 3 (relative incidence [RI], 1.71 [95% confidence interval {CI} 0.0–5.11]). Similarly, no increased risk during 8–21 days after the dose 1 (zero cases observed), dose 2 (RI, 0.71 [95% CI, 0.0–3.28]) or dose 3 (RI, 2.52 [95% CI, 0.78–5.61]). The results were similar for 1–21 day periods after the doses separately or pooled.

Conclusions

The risk of intussusception during the first 21 days after any dose of rotavirus vaccine (Rotavac) was not higher among the Indian infants than the background risk, based on limited SCCS analysis of 52 children.

The risk of Kawasaki disease after pneumococcal conjugate & meningococcal B vaccine in England: A self-controlled case-series analysis

Kawasaki disease (KD) is an uncommon condition occasionally reported after childhood vaccination. Admissions with a KD-compatible diagnosis identified from a national database in England were linked to immunisation records to investigate the risk after pneumococcal conjugate (PCV) or meningococcal B (MenB) vaccines. Both are given at 2/4/12 months of age but were introduced sequentially, allowing their effects to be separately assessed. A total of 553 linked admissions in 512 individuals were validated as KD. The relative incidence (RI) within 28 days of PCV doses 1 or 2 measured by the self-controlled case-series method was 0.62 (95% confidence interval (CI) 0.38-1.00) with a significantly decreased risk after dose 3 (RI 0.30 (95% CI 0.11-0.77)). For MenB vaccine, the RI after doses 1 or 2 was 1.03 (95% CI 0.51-2.05) and 0.64 (95% CI 0.08-5.26) after dose 3. This study shows no evidence of an increased risk of KD after either vaccine.

No increased risk of Guillain-Barré syndrome after human papilloma virus vaccine: A self-controlled case-series study in England

OBJECTIVE

To investigate the risk of Guillain-Barré syndrome (GBS) after human papilloma virus (HPV) vaccine given to 12-18year old girls in England.

METHODS

Hospital Episode Statistics (HES) were searched using data to March 2016 to identify incident cases of GBS in female patients aged from 11 to 20years eligible to have received the HPV vaccine since its introduction as a 3 dose schedule in September 2008. Diagnosis was confirmed by the case's general practitioner (GP) who also provided HPV vaccination dates. The risk of admission within 3months (primary risk window) 6 and 12months of any dose was assessed using the self-controlled case-series (SCCS) method in vaccinated girls with age, season and time-period adjustment. The risk before and after the change in 2012 from bivalent vaccine to quadrivalent vaccine was also assessed.

RESULTS

A total 244 episodes were initially identified which reduced to 101 episodes in 100 girls when just including cases where the GP could be contacted, at least one vaccine dose was given, and GBS was confirmed or classed as probable. Nine, 14 and 24GBS admissions occurred within 3, 6, 12months of a dose respectively. The relative incidence (RI) for the 3month risk period was 1.04 (95% confidence interval 0.47-2.28), for the 6month period 0.83 (0.41-1.69) and for the 12month period 1.10 (0.57-2.14). When restricting to 79 confirmed cases the RI in the 3month risk period was 1.26 (0.55-2.92) and the RI 1.61 (0.39-6.54) for quadrivalent vaccine compared to 0.84 (0.30-2.34) for bivalent.

CONCLUSION

We found no evidence of an increased risk of GBS following HPV vaccination in England and, based on the upper end of the 95% CI for the RI and the number of HPV vaccine doses given in England, can exclude a risk of about 1 per million doses.

The risk of intussusception following monovalent rotavirus vaccination in England: A self-controlled case-series evaluation

OBJECTIVE

To investigate the risk of intussusception after monovalent rotavirus vaccine (RV1) given to infants aged 2 and 3 months in England.

METHODS

Hospital Episode Statistics (HES) were used to identify infants aged 48-183 days admitted between 11/03/2013 and 31/10/2014 with intussusception. Diagnosis was confirmed from medical records and HES procedure codes. Vaccination status was obtained from general practitioners. The risk of admission within 1-7 and 8-21 days of vaccination was analysed using the self-controlled case-series (SCCS) method with age effect adjustment by including historical data before RVI introduction in July 2013.

RESULTS

A total of 119 cases were identified during the study period and intussusception confirmed in 95 of whom 39 were vaccinated 1-21 days before onset. An increased relative incidence (RI) in this period was found, 4.53 (95% confidence interval 2.34-8.58) and 2.60 (1.43-4.81) respectively after the 1st and 2nd doses with an attributable risk of 1.91 and 1.49 per 100,000 doses respectively. The peak risk was 1-7 days after the first dose, RI 13.81 (6.44-28.32), with an estimated 93% of the 15 cases being vaccine-attributable. Mean interval between onset and admission, and clinical features were similar between vaccine-associated and background cases. Despite intussusception being a contraindication to rotavirus vaccination, 10 infants received a further dose; none had a recurrence. The RIs in a meta-analysis combing our results with Australia, Mexico, Brazil and Singapore using RV1, a 2, 4 month schedule and SCCS gave pooled RI estimates of 2.35 (1.45-3.8) and 1.77 (1.29-2.43) in the 21 day period after the 1st and 2nd doses, respectively. The earlier age at the 2nd dose in England did not affect the risk.

CONCLUSION

We estimate that the RVI programme causes around 21 intussusception admissions annually in England but, since it prevents around 25,000 gastro-intestinal infection admissions, its benefit/risk profile remains strongly positive.