BACKGROUND: The COVID-19 pandemic had a profound impact on healthcare systems and services, including routine immunization (RI). To date, there is limited information on the effects of the COVID-19 pandemic on RI in West African countries such as Sierra Leone, which had already experienced public health emergencies that disrupted its healthcare system. Here, we describe the impact of the COVID-19 pandemic on the RI of key antigens in Sierra Leone.
METHODS: We used vaccination data from the District Health Information System for BCG, measles-rubella 1 and 2, and pentavalent 1 and 3 antigens. We compared 2019, 2020, 2021, and 2022 annual coverage rates for the selected antigens at the national and district levels. We used the Pearson chi-square test to assess the difference between annual coverage rates between 2019 and 2020, 2020-2021, and 2021-2022.
RESULTS: National coverage rates for all antigens declined in 2019-2020, notably measles-rubella 1 and pentavalent 3 (-5.4% and - 4.9%). Between 2020 and 2021, there was an overall increase in coverage (+ 0.2% to + 2.5%), except for measles-rubella 2 (-1.8%). Measles-rubella antigens rebounded in 2021-2022, while others decreased between - 0.5 and - 1.9% in coverage. Overall, all district-level coverage rates in 2022 were lower than those in 2019. Most districts decreased between 2019 and 2022, though a few had a continuous increase; some had an increase/recovery between 2020 and 2021; some districts had recovered 2019 levels by 2022.
CONCLUSIONS: The COVID-19 pandemic impacted Sierra Leone\'s national BCG, measles-rubella, and pentavalent antigen immunization, which were not fully restored in 2022. Most districts experienced notable coverage declines during the pandemic, though a few reached or surpassed 2019 rates in 2022. Examining pandemic impact can benefit from a focus beyond the national level to identify vulnerable regions. Sierra Leone\'s post-pandemic RI reestablishment needs targeted strategies and continual investments for equitable access and coverage, as well as to prevent vaccine-preventable diseases.

UNASSIGNED: Timely vaccination of children is one of the most cost-effective interventions that ensure childhood survival. We determined the proportion of children who received timely vaccination and examined the factors associated with timely receipt of Bacillus Calmette Guerin (BCG) and third dose of pentavalent vaccine (Penta 3).
UNASSIGNED: We conducted a cross-sectional survey among 599 caregivers-infant pair aged less than 24months, attending the immunization clinic of a tertiary hospital in Nigeria, selected using systematic sampling methods. Using a structured questionnaire, we access the proportion of children who received timely vaccination, the relationship between the timely receipt of BCG, Penta 3 vaccine and infant/caregiver characteristics was examined using chi-square and multiple logistic regression at a 5% level of significance.
UNASSIGNED: The mean age of the respondents was 30.1±5.0 years. The majority (73.8%) had attained tertiary education, lived in an urban setting (90.9%), had received antenatal care during pregnancy (99.3%) and was delivered in a hospital (97.0%). About half of the children (52.9%) were male. About 18% of the caregivers reported missing scheduled immunization visits, due to forgetfulness (18%), child illness (14%) and being busy (5%). About 88% (482) of the children got their BCG vaccines on time, 91.1% got timely OPV0, however, only 29.5% of the newborns got HBV0 within 24 hours of birth. Only 65.7% and 65.0% received the timely measles-containing vaccine and yellow fever vaccine. None of the factors examined predicted timely receipt of BCG and Penta 3 vaccines.
UNASSIGNED: Interventions that remind caregivers about the immunization schedules, could improve timely vaccination.

The development of an effective combined vaccine represents a crucial strategy for preventing outbreaks of infectious diseases and reducing the burden on healthcare resources. Developing a combined vaccine against both influenza and the coronavirus is a promising approach, but it is still in the early stages of development. This paper reports on a novel combined pentavalent candidate vaccine that has shown promising results in mice, with statistically significant differences in mean antibody titer against the coronavirus and the influenza antigens compared to placebo. We have shown that the coronavirus antigen is capable of inducing an immune response autonomously, regardless of the presence of the influenza antigens in a combined vaccine. On the other hand, the presence of the coronavirus antigen in a combined vaccine showed to enhance the immune response against some of the studied influenza antigens, suggesting that these antigens may act in synergy and elicit an enhanced immune response. The absence of dose-dependent difference in mean antibody titer within the same antigenic groups of vaccine preparations suggested that even small amounts of the coronavirus and the influenza antigens could induce an immune response just as good as high-dose vaccine preparations, which certainly has important safety and cost implications. The vaccine is soon to be ready for clinical trials and mass production.

UNASSIGNED: One of the most significant current discussions in pediatrics is whether lumbar puncture (LP) should be performed in children with febrile seizure (FS) as in the past.
UNASSIGNED: We compared the prevalence of meningitis among FS children before and after the pentavalent vaccine to determine the importance of the LP in these children.
UNASSIGNED: We performed a retrospective cross-sectional study on the prevalence and etiology of bacterial meningitis (BM) in 1314 children with FS before and after pentavalent vaccination.
UNASSIGNED: We found that complex FS was more prevalent in patients aged under 12 months compared to other patients. The peak incidence of aseptic meningitis and BM was in the age group of 12- to 18- and 18- to 36-month-old, respectively (P value <0.001 and <0.05, respectively). Children with complex FS had a significantly higher rate of BM and a lower rate of seizure recurrence than those with simple FS (P value <0.05). There was a significant relationship between getting the pentavalent vaccine and reducing the prevalence of BM and Hib-induced BM, but no SP-induced BM (P value <0.05 and 0.05 and 0.104, respectively).
UNASSIGNED: This study offers some insights into the effectiveness of the pentavalent vaccine. In addition, the low prevalence of BM in vaccinated FS cases does not support strong recommendations for LP in FS children.

UNASSIGNED: SARS-CoV-2 has resulted in a global public health crisis. During the pandemic, considerable delay was observed making it impossible for some children to receive their due vaccines on time. Like most resource-poor countries, COVID-19 pandemic is thought to have a negative impact on Somalia\'s immunization coverage.
UNASSIGNED: This study aimed to assess the impact of the COVID-19 pandemic on routine childhood immunization coverage in Somalia. A retrospective comparative cross-sectional approach was employed to investigate the number of under-5-year children who got their immunization from the two major mother and child hospital, (Banadir and SOS hospitals) in Mogadishu, Somalia from October 2019 to December 2020. To do this, a total of 112, 060 data relating to the routine childhood immunization (measles, polio, whooping cough, hepatitis B, pneumonia, and tuberculosis) were collected from the monthly immunization report-data from the two hospitals.
UNASSIGNED: The results showed that all the vaccines except birth vaccines have remarkably dropped with Penta-3 (27%), Penta-2 (11%), measles (10%) and Penta-1 (8%) respectively. However, the birth vaccines (BCG and Polio 0) were not affected as observed in this study. The reduction in children immunization rate in Somalia may be a combination of many other factors, we however recognize that the COVID-19 pandemic may have contributed significantly to this outcome .
UNASSIGNED: The government needed to take proactive measures to encourage parents to present their children for immunizations, including increasing community awareness concerning the importance of these routine childhood immunizations despite the ongoing COVID-19 pandemics.

The annual increase in the number of camels entails a parallel increase in the incidence of trichophytosis, which poses a great threat to the health and life of both this species of animals and other organisms that contact and surround them.
The aim of the study was to develop and establish the quality of vaccines inactivated by ultrasonic exposure for the prevention and treatment of trichophytosis in camels, and to compare them with chemically deactivated vaccines.
The peculiarity of the technology of production of these vaccines was the use of an innovative method of inactivation of fungal strains by ultrasonic waves, which allowed to achieve high positive results in theory, and was subsequently confirmed in practice by immunizing sick and healthy animals. The first tests of the obtained vaccines were conducted in laboratory conditions on experimental rabbits.
The results of prophylactic and therapeutic vaccinations were one hundred percent positive, which made it possible to conduct further tests directly on camels of industrial farms, the expected result of which was also positively confirmed at the end of the research.
As a result of this experiment, the effectiveness, stability, and safety of the manufactured vaccines were established, which made it possible to approve the regulatory and technical documentation and patent them as an innovative and effective development for the prevention and treatment of camel trichophytosis, which will reduce the growth of infection and further overcome the mass spread of the disease both among camels and among the surrounding organisms to which it is transmitted.

Debate regarding vaccinating high-risk infants with penta- and hexavalent vaccines persists, despite their good immunogenicity and acceptable safety profile in healthy full-term infants. We report the findings of a systematic literature search that aimed to present data on the immunogenicity, efficacy, effectiveness, safety, impact, compliance and completion of penta- and hexavalent vaccination in high-risk infants, including premature newborns. Data from the 14 studies included in the review showed that the immunogenicity and the safety profile of penta- and hexavalent vaccines in preterm infants was generally similar to those seen in full-term infants, with the exception of an increase in cardiorespiratory adverse events such as apnea, bradycardia and desaturation following vaccination in preterm infants. Despite recommendations of vaccinating preterm infants according to their actual age, and the relatively high completion rate of the primary immunization schedule, vaccination was often delayed, increasing the vulnerability of this high-risk population to vaccine-preventable diseases.
Combined vaccines such as penta- and hexavalent vaccines against multiple childhood diseases are widely used in healthy babies born at term. However, it is still debated whether these vaccines act the same way in babies considered to be high-risk: babies born prematurely at <34 weeks of pregnancy, those with a birthweight of <1500 g or babies with chronic diseases. We did a systematic literature search to find studies on such high-risk babies vaccinated with penta- or hexavalent vaccines; we focused on their antibody levels following vaccination, side effects, and protection from the diseases against which they were vaccinated. We also analyzed whether they were vaccinated on time and with all the doses recommended for healthy full-term babies. We found 14 studies that included premature babies. The results of these studies suggest that premature babies’ immune systems respond to penta- and hexavalent vaccines in largely the same way as those of full-term babies; side effects of penta- and hexavalent vaccines are also mostly similar to those seen in full-term babies. However, side effects like pauses in breathing, slow heart rate or low blood oxygen levels seem to be more common in preterm babies; for safety, these babies should be monitored closely after vaccination. Preterm babies are often vaccinated with a delay compared to the recommended schedule. No studies reported data on protection from the diseases covered by penta- and hexavalent vaccinations in preterm babies. More research is needed on penta- and hexavalent vaccination of other high-risk babies besides those born prematurely.

UNASSIGNED: Since November 2014, the pentavalent (Diptheria+Tetanus+Pertussis and Hepatitis B and Hib or DTP-HBHib) vaccine has been integrated into the Iranian national vaccination programme.
UNASSIGNED: We conducted a prospective study in Zahedan in the southeast of the Islamic Republic of Iran to determine the incidence of adverse events following immunization (AEFI) with the pentavalent vaccine in children aged under one year.
UNASSIGNED: Using cluster sampling, 1119 children aged 2-10 months at 15 public health clinics were invited, through their parents, to participate in the study. The parents were trained to register and report any AEFIs in a questionnaire. They were instructed to return the child to the clinic for further examination by a physician if they observed any complications within 3 days of vaccination.
UNASSIGNED: The most commonly reported AEFIs were fever (50.94%), mild (41.46%) and severe (1.70%) injection site complications, persistent crying for 3 hours or more (1.88%), hypotonic hyporesponsive episode (0.36%), vomiting (1.88%), diarrhoea (2.95%), and sterile abscess (0.62%). There were no cases of convulsion, purulent abscess or rash. The work experience of vaccinators (OR = 1.85; 95% CI: 1.4-2.46) showed a significant statistical association with the incidence of mild local complications at the injection site. Those with a history of Bacillus Calmette-Guérin (BCG) lymphadenitis (OR = 3.89; 95% CI:1.04-14.49) had a higher risk of severe local complications at the injection site.
UNASSIGNED: The observed incidence of serious AEFIs following pentavalent vaccine injection in the study population was within the expected range. However, some of the relationships observed in this study require further research.
الأحداث الضارة الشديدة بعد التطعيم باللقاح خماسي التكافؤ في السنة الأولى من العمر.
شاهروخ إيزادي، مهدي محمدي، ماجد سرتبي، منوشهر كرامي، حسين كريمي.
UNASSIGNED: أُدرِج اللقاح الخماسي التكافؤ (الدفيتريا + السعال الديكي (الشاهوق) + التيتانوس والتهاب الكبد B ولقاح المستدمية النزلية من النوع ب أو اللقاح الثلاثي HB-Hib) في برنامج التطعيم الوطني الإيراني منذ نوفمبر/ تشرين الثاني 2014.
UNASSIGNED: هدفت هذه الدراسة الاستباقية التي أجريت في زاهدان، بجنوب شرق جمهورية إيران الإسلامية، الى تحديد معدل وقوع الأحداث الضارة بعد التطعيم باللقاح الخماسي في حالة الأطفال الذين تقل أعمارهم عن عام واحد.
UNASSIGNED: باستخدام الطريقة العنقودية لأخذ العينات، دُعي 1119 طفلًًا، تتراوح أعمارهم بين شهرين و10 أشهر للمشاركة في هذه الدراسة في 15 عيادة صحية عامة، ووُجهت الدعوة إلى آبائهم. وجرى تدريب الآباء على تسجيل كل حدث ضار بعد التطعيم والإبلاغ عنه في استبيان. كذلك طُلب من الآباء التوجه بالطفل إلى العيادة ليُجري الطبيب المزيد من الفحوص، إذا لاحظوا مضاعفات خلال 3 أيام من تلقِّي اللقاح.
UNASSIGNED: كانت أكثر الأحداث الضارة بعد التطعيم شيوعًا: الحمى (50.94٪)، والمضاعفات المتوسطة (41.46٪)، والمضاعفات الشديدة (1.70٪) في موضع الحَقْن، والبكاء المستمر 3 ساعات أو أكثر (1.88٪)، ونوبات نقص استجابة الدم لنقص التوتر (0.36٪)، والقيء (1.88٪)، والإسهال (2.95٪)، والخراج العقيم (0.62٪). ولم تُسجل حالات تشنُّج أو خراج قيحي أو طفح جلدي. وأظهرت الخبرة العملية للقائمين على التطعيم (نسبة الأرجحية = 1.85؛ 95٪ فاصل الثقة: 1.4 – 2.46) ارتباطًا إحصائيًّا كبيرًا، مع حدوث مضاعفات موضعية خفيفة في موضع الحَقْن. وأولئك الذين سبق أن أُصيبوا بالتهاب الغدد الليمفاوية بعصيات كالميت جيران (BCG) أكثر عرضة للمضاعفات الموضعية الحادة في موضع الحقن (نسبة الأرجحية = 3.89؛ 95٪ فاصل الثقة: 1.04 – 14.49).
UNASSIGNED: إن معدل ملاحظة وقوع أحداث خطرة ضارة بعد التطعيم بتلقِّي حَقْن اللقاح الخماسي التكافؤ بين مجتمع الدراسة ضمن النطاق المتوقع. ورغم ذلك، فإن بعض العلاقات التي لوحظت في هذه الدراسة تستحق المزيد من البحث.
Manifestations postvaccinales indésirables aiguës liées au vaccin pentavalent DTCHB-Hib au cours de la première année de vie.
UNASSIGNED: Depuis novembre 2014, le vaccin pentavalent (diphtérie, tétanos, coqueluche, hépatite B et Hib ou DTCHB- Hib) est intégré au programme national de vaccination iranien.
UNASSIGNED: Nous avons mené une étude prospective à Zahedan, dans le sud-est de la République islamique d\'Iran, afin de déterminer l\'incidence des manifestations postvaccinales indésirables (MAPI) liées au vaccin pentavalent chez les enfants âgés de moins d\'un an.
UNASSIGNED: Au moyen d\'un sondage par grappe, 1119 enfants âgés de 2 à 10 mois fréquentant 15 centres de soins de santé publique ont été invités à participer à l\'étude, par l\'intermédiaire de leurs parents. Ces derniers ont été formés pour enregistrer et signaler toutes MAPI en répondant à un questionnaire. Ils ont reçu pour instruction de reconduire l\'enfant au centre de soins de santé pour qu\'il soit examiné de manière plus approfondie par un médecin s\'ils observaient des complications dans les trois jours suivant la vaccination.
UNASSIGNED: Les MAPI les plus fréquemment signalées étaient les suivantes : fièvre (50,94 %), complications bénignes (41,46 %) et graves (1,70 %) au point d\'injection, pleurs persistants pendant au moins trois heures (1,88 %), épisodes d\'hypotonie-hyporéactivité (0,36 %), vomissements (1,88 %), diarrhée (2,95 %) et abcès stérile (0,62 %). Il n\'y a pas eu de cas de convulsions, d\'abcès purulent ou d\'éruption cutanée. L\'expérience professionnelle des agents de vaccination (OR = 1,85 ; IC à 95 % : 1,4-2,46) affichait une association statistique significative avec l\'incidence des complications locales bénignes au point d\'injection. Ceux qui avaient des antécédents de lymphadénite liée au vaccin Bacille Calmette-Guérin (BCG) (OR = 3,89 ; IC à 95 % : 1,04-14,49) présentaient un risque plus élevé de complications locales graves au point d\'injection.
UNASSIGNED: L\'incidence des MAPI graves observée dans la population de l\'étude après l\'administration du vaccin pentavalent se situait dans la fourchette attendue. Toutefois, certaines des relations examinées dans la présente étude nécessitent des recherches plus approfondies.

In Atlantic salmon, vaccines have failed to control and prevent Piscirickettsiosis, for reasons that remain elusive. In this study, we report the efficacy of two commercial vaccines developed with the Piscirickettsia salmonis isolates AL100005 and AL 20542 against another two genogroups which are considered highly and ubiquitously prevalent in Chile: LF-89 and EM-90. Two cohabitation trials were performed to mimic field conditions and vaccine performance: (1) post-smolt fish were challenged with a single infection of LF-89, (2) adults were coinfected with EM-90, and a low level coinfection of sea lice. In the first trial, the vaccine delayed smolt mortalities by two days; however, unvaccinated and vaccinated fish did not show significant differences in survival (unvaccinated: 60.3%, vaccinated: 56.7%; p = 0.28). In the second trial, mortality started three days later for vaccinated fish than unvaccinated fish. However, unvaccinated and vaccinated fish did not show significant differences in survival (unvaccinated: 64.6%, vaccinated: 60.2%, p = 0.58). Thus, we found no evidence that the evaluated vaccines confer effective protection against the genogroups LF-89 and EM-90 of P. salmonis with estimated relative survival proportions (RPSs) of -9% and -12%, respectively. More studies are necessary to evaluate whether pathogen heterogeneity is a key determinant of the lack of vaccine efficacy against P. salmonis.

This study aimed to assess the safety of a fully liquid DTwP-HBV/Hib pentavalent vaccine (EupentaTM) based on the occurrence of adverse events (AEs) following vaccination.
This was a prospective, open-label, single-arm, interventional phase IV study. A single intramuscular injection of the study vaccine was administered to infants at approximately 6, 10, and 14 weeks of age, and an end-of-study follow-up visit was scheduled at 18 weeks.
In all, 3000 subjects were enrolled and received at least one dose of the study vaccine. Of these, 2717 (90.6%) experienced at least one AE. Immediate reactions, solicited and unsolicited AEs were respectively identified in 224 (7.5%), 2,652 (88.4%), and 1,099 (36.6%) subjects. The most prevalent solicited and unsolicited AEs comprised pain/tenderness and upper respiratory tract infection, respectively. Most AEs were mildly or moderately severe. Forty-one (1.4%) subjects had at least one serious AE (SAE); of these, two (0.1%) had two SAEs each, considered related to the study vaccine. Six (0.2%) subjects died due to unsolicited AEs, none of which were considered related to the study vaccine. No AEs were reported at the end-of-study follow-up visit.
The study vaccine  had a safety profile similar to that reported in a previous clinical study, and did not result in an increased risk of AEs known to be associated with DTwP-based vaccines or previously unrecognized SAEs.