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

Abstract

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 16.865.19 years (ranged: 6-35.5 years). Each person reported a mean of 1.3360.6 AEFI. The average AEFI onset duration was 1.7461.16 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.

Assessment of attitudes towards adverse events following immunization with oral poliovirus vaccine: a pilot study among high school students of Kinshasa, the Democratic Republic of Congo

“…12 This article should be complementary and gives an idea of the proportion of students who experienced AEFI. In our study, 136 students (16.4%) reported experiencing an AEFI.…”

“…This high level of knowledge could explain why the immunization coverage was the highest during the third round in this study group (96.8%), while the number of people accepting immunization was the lowest in the general population during the same period. 12 However, the survey was realized in urban area, among high students in Kinshasa. This is representative of neither the whole population of Kinshasa nor the population of the DRC, but gives us an idea about how knowledge can influence attitudes towards immunization.…”

“…In May, bivalent OPV types 1 and 3 (biOPV) was administered to 9 724 982 persons and 10 206 785 persons received mOPV1 in June. 12 One of the main reasons for the decrease in immunization coverage during the third round was the spread of a rumor that OPV was responsible for an outbreak of conjunctivitis, which occurred during the same period as the mass immunization campaign. An Adverse Event Following Immunization (AEFI) is defined as 'any untoward medical occurrence which follows immunization and which does not necessarily have a causal relationship with the usage of the vaccine'.…”

The Characteristics of Families who rejected Vaccination during the Mop-up Oral Polio Vaccination Campaign and Their Reasons of Rejection: A Family Health Center Experience

“…Aşının zararlı olma ihtimalinin ailelerde korku oluşturduğu birçok çalışmada gösterilmiştir. Nzolo ve ark.nın Demokratik Kongo Cumhuriyeti'nde oral polio aşısını takiben gelişen yan etkilerini araştırdıkları sürveyans çalışmasında en sık yan etki olarak baş ağrısı tespit edilmiştir (6). Baş ağrısı, kırgınlık, aşı yerinde kızarıklık gibi tanımlanan bulgular diğer rutin aşılarda tanımlanan ve gözlemlenen bulgularla benzer bulunmuştur (7-9).…”

“…Nzolo ve ark. nın yaptığı bu çalışma kapsamında yaklaşık 10 milyon kişi aşılanmış ve OPA'nın ilk dozunu takiben sadece 2 olguda paralizi gelişmiş, bu oran DSÖ'nün bildirdiği OPA ilişkili paralitik poliomiyelit gelişme riskinden (1/1.4-3.4 milyon) bile daha düşük tespit edilmiştir (6,10). Düşük eğitim seviyesi ve aşılamanın reddi arasındaki ilişki pek çok çalışmada gösterilmiştir.…”