Incidence of adverse events among healthcare workers following H1N1 Mass immunization in Ghana: a prospective study

A review of the safety of vaccines used in routine immunization in Africa

BACKGROUND

Despite the significant role played by vaccines in global health, concerns over vaccine safety have increased tremendously over the years. There have been occasions where vaccines have caused rare, adverse reactions some of which have led to hospitalizations and even death. It is therefore important to establish the safety profile of routinely used vaccines in order to allay fears pertaining to their use.

OBJECTIVES

This review was aimed at pooling together the safety data of selected vaccines used for routine immunization in Africa, a region of the world with paucity of vaccine safety data.

METHODS

Adverse Events Following Immunization safety data was searched for rotavirus, yellow fever, measles, rubella, tuberculosis (Bacillus Calmette Guerin-BCG), pneumococcal, Haemophilus Influenza type b, polio, meningococcal and the influenza A (H1N1) vaccines in PUBMED, Google Scholar, Clinical trials.gov and Cochrane controlled register of trials databases.

RESULTS

A total of twenty-four serious AEFIs and twenty-three minor AEFIs were identified from the review. The strength of association between AEFIs and vaccine was high for tuberculosis vaccine and moderate for all other vaccines.

CONCLUSION

Even though AEFIs (including mild and severe) were identified in the review, all the vaccines studied were generally well tolerated.

Intensive Monitoring Studies for Assessing Medicines: A Systematic Review

Introduction: Intensive monitoring (IM) is one of the methods of post-marketing active surveillance based upon event monitoring, which has received interest in the current medicines regulatory landscape. For a specific period of time, IM involves primary data collection and is actively focused on gathering longitudinal information, mainly safety, since the first day of drug use. Objectives: To describe IM systems and studies' data published over 11-years period (2006-2016). Specifically, we reviewed study population/event surveillance, methodological approaches, limitations, and its applications in the real-world evidence generation data. Methods: We completed a systematic search of MEDLINE and EMBASE to identify studies published from 2006 to 2016, that used IM methodology. We extracted data using a standardized form and results were analyzed descriptively. The methodological quality of selected studies was assessed using the modified Downs and Black checklist. Results: From 1,400 screened citations, we identified 86 papers, corresponding to 69 different studies. Seventy percent of reviewed studies corresponded to established IM systems, of which, more than half were prescription event monitoring (PEM) and modified-PEM. Among non-established IM systems, vaccines were the most common studied drugs (n = 14). The median cohort size ranged from 488 (hospitals) to 10,479 (PEM) patients. Patients and caregivers were the event data source in 39.1% of studies. The mean overall quality score was similar between established and non-established IM. Conclusions: Over the study period, IM studies were implemented in 26 countries with different maturity levels of post-marketing surveillance systems. We identified two major limitations: only 20% of studies were conducted at hospital-level, which is a matter of concern, insofar as healthcare systems are facing a lack of access to new medicines at ambulatory care level. Additionally, IM access to data of drug exposure cohorts, either at identification or at follow-up stages, could somehow constitute a barrier, given the complexity of managerial, linkable, and privacy data issues.

Reporting of adverse events following immunizations in Ghana - Using disproportionality analysis reporting ratios

BACKGROUND

Timely reporting of safety information post vaccination is pivotal for the success of any vaccination program. Reports of adverse events following immunization (AEFI) of 6 different vaccinations from Ghana were analysed for signals.

METHODS

De-identified data from active surveillance for AEFIs after 2009 AH1N1 influenza, yellow fever, meningitis, measles-rubella, pneumococcal-rotavirus and human papilloma virus vaccinations were used. All vaccinations occurred between January 2010 and December 2013. The ten most occurring events for each vaccination were captured and arranged using Medical Dictionary for Regulatory Authorities (MedDRA) Preferred Term (PT) and System Organ Classification (SOC) codes. Adverse event incidence rates were calculated for each vaccine type, and signals were generated using proportional reporting ratios (PRR).

RESULTS

A total number of 5,141 reports were analysed ranging from 33 (human papilloma virus) to 1958 (measles-rubella). Between 22% and 55% of all AEFIs per vaccine type were collected on the day of vaccination. For each vaccine type, at least 87% of all reported AEFIs occurred in the first 7 days post-vaccination. Multiple reports were received per vaccine type. For the MR vaccine, urticarial recorded the highest attack rate of 6.6 (95% CI 6.2, 7.1) per 100,000 vaccines. The AEFI with the highest PRR for both human papilloma and measles-rubella vaccines was abdominal pain, recording a PRR of 8.15 (95% CI 3.46, 19.23) and 43.75 (95% CI 17.81, 107.45) respectively.

CONCLUSION

These results underscore the competency of public health systems in sub-Saharan African countries (like Ghana) to identify most frequently occurring and important vaccine related safety issues.

Adverse events following immunization with oral poliovirus in Kinshasa, Democratic Republic of Congo: preliminary results

AIM

We investigated the nature and frequency of adverse events following immunization (AEFI) associated with oral polio vaccines (OPV) in the general population in Kinshasa, Democratic Republic of Congo (DR Congo).

METHODS

The DR Congo National Pharmacovigilance Centre organized active AEFI surveillance during mass immunization campaigns for the general population from March to June 2011. A patient individual case safety report was used as a questionnaire and addressed to pupils and students from high schools and universities who had any adverse events after OPV administration. We used the preferred term from the WHO Adverse Reaction Terminology for AEFI designation. Here is presented the results of the second step of the mass immunization campaign.

RESULTS

A total of 767 patients reported AEFI during the second step. Sex distribution shows that 512 (66·8%) students were females, while 255 (33·2%) were males, giving a female/male ratio 2∶1. The average age was 16·8±5·19 years (ranged: 6-35·5 years). Each person reported a mean of 1·33±0·6 AEFI. The average AEFI onset duration was 1·74±1·16 days post-vaccination, ranging from 1 to 9 days. Headache (22·4%), abdominal pain (17·2%), fever (11·7%), diarrhea (9·9%), and asthenia (7·5%) were the common symptoms. Paralysis and asthma-like reactions were rare and serious adverse events in this study. The most affected systems were gastro-intestinal (33·5%) and nervous system (29·3%). Rechallenge was positive for 173 persons (22·6%).

CONCLUSION

OPV-related AEFIs are not uncommon, although it is under-reported. Active AEFI surveillance during mass immunization campaigns is very important and may help to detect rare and serious adverse events. Further investigation will be important to identify risk of AEFI with OPV in adults and is warranted to elucidate the cause of this association in the Congolese environment.