Assessment of Strengths and Weaknesses of Inactivated Polio Vaccine Practices in Qasimabad, Pakistan

Objectives: The objectives of the study were to assess the strengths and weaknesses of inactivated polio vaccine (IPV) practices in Qasimabad, Pakistan. Material and Methods: This cross-sectional survey study was conducted in Hyderabad, Sindh, from June 22, 2017, to September 22, 2017. It included seven expanded programs on immunization (EPI) centers in Taluka Qasimabad, as well as outreach settings. Data were collected through convenience sampling with the help of an EPI Monitoring Checklist and a pre-designed questionnaire. Statistical Package for the Social Sciences version 23.0 was used for the descriptive analysis. Results: Six of the seven health facilities were found to be screening for missed opportunities. During power outages or load shedding, the majority of EPI centers (85.7%) had a backup plan in place. However, the major shortcoming was the failure to obtain parental consent before vaccination by vaccinators at all 7 (100%) EPI centers. At 5 (71.9%) of the centers, outreach activities to vaccinate children were organized, and IPV was only given to infants at 1 (19.2%) of the sessions. The vaccinator opened the vial before using it, and the used IPV vial was not discarded at the end of the outreach session. Because one center’s vaccinator was female (19.2%), and another center’s vaccinator was single (19.2%), no outreach activity was planned at those two locations. Conclusion: This research highlights the benefits and drawbacks of the current EPI program for the IPV vaccine. The presence of EPI centers at all health facilities, as well as the availability of IPV and cold chain equipment, as well as permanent and fully-trained employees, are some of the most important strengths. Lack of pre-service training and adverse events following immunization vaccine training were identified as weaknesses. There are a lack of IPV refresher training, as well as improper arrangements for outreach vaccination sessions, and a lack of transportation for vaccinators.

Tingkat Pengetahuan Mahasiswa Fakultas Kedokteran Universitas Yarsi Mengenai Penggunaan Human Diploid Cell Dalam Proses Produksi Vaksin Polio

Latar Belakang : Vaksin merupakan suspensi mikroorganisme yang dilemahkan atau dimatikan, atau protein antikgenik dari berbagai organisme tadi yang diberikan untuk mencegah, meringankan, atau mengobati penyakit-penyakit menular. Vaksin pertama kali tercatat pada tahun 1769, yang dipublikasikan oleh Edward Jenner, yaitu specimen yang berasal dari lesi lengan seseorang yang terinfeksi Cowpox. Human Diploid Cells (HDC) merupakan salah satu sel yang digunakan untuk mengkultur virus yang akan dijadikan vaksin. HDC yang berasal dari aborsi manusia ini banyak digunakan untuk mengkultur virus Polio IPV dan OPV, Rabies, Rubella, Measles, Varicella-Zooster, dan Hepatitis A. Tujuan : Vaksin polio merupakan vaksin yang diwajibkan pada anak yang dijadwalkan dari Ikatan Dokter Anak Indonesia (IDAI) yang dibagi menjadi dua jenis, IPV (Inactivated Polio Vaccine) dan OPV (Oral Polio Vaccine). Metode : Jenis Penelitian yang digunakan adalah deskriptif dengan pendekatan cross sectional menggunakan kuesioner. Populasi yang digunakan adalah mahasisa Fakultas Kedokteran Universitas YARSI tahun pertama dan tahun ketiga yang memenuhi syarat. Cara pemilihan sampel dengan simple random sampling. Hasil : Penelitian yang dilaksanakan selama 3 hari dengan menggunakan kuesioner, dari 100 responden didapatkan persentase jumlah kuesioner Pengetahuan mengenai Human Diploid Cell berdasarkan Tingkat Pendidikan didapatkan pengetahuan baik sebanyak 5% pada tahun ketiga dan 7% pada tahun pertama. Pengetahuan cukup sebanyak 23% pada tingkat ketiga dan 28% pada tahun pertama. Pengetahuan kurang sebanyak 9% pada tingkat ketiga dan 28% pada tahun pertama. Persentase jumlah kuesioner Pengetahuan mengenai Polio berdasarkan Tingkat Pendidikan didapatkan pengetahuan baik sebanyak 15% pada tahun ketiga dan 19% pada tahun pertama. Pengetahuan cukup sebanyak 18% pada tingkat ketiga dan 31% pada tahun pertama. Pengetahuan kurang sebanyak 4% pada tingkat ketiga dan 13% pada tahun pertama. Kesimpulan : Tidak terdapat hubungan antara tingkat pendidikan dengan pengetahuan mengenai Human Diploid Cell dalam vaksin Polio. Dalam pandangan Islam, penggunaan vaksin Polio hukumnya mubah karena prinsip Dharuriyat bertujuan untuk mempertahankan nyawa atau Hifdz an-nafs anak dari ancaman penyakit.

Assessing vaccine introduction and uptake timelines in Gavi-supported countries: are introduction timelines accelerating across vaccine delivery platforms?

BackgroundPrevious studies identified factors influencing regulatory approval to introduction timelines for individual vaccines. However, introduction and uptake timelines have not been comprehensively assessed across the portfolio of Gavi-supported vaccines.MethodsWe analysed median times between introduction milestones from vaccine licensure to country introduction and uptake across six vaccine-preventable diseases (VPDs), three delivery platforms and 69 Gavi-supported countries. Data were gathered from public, partner and manufacturer records. VPDs and prequalified vaccines analysed included Haemophilus influenzae type b (DTwP-HepB-Hib, pentavalent), pneumococcal disease (pneumococcal conjugate vaccine, PCV), rotavirus diarrhoea (rotavirus vaccine, RVV), cervical cancer (human papillomavirus vaccine, HPV), polio (inactivated polio vaccine, IPV) and meningococcal meningitis (meningococcal group A conjugate vaccine, MenA).ResultsMedian time from first vaccine licensure to first Gavi-supported country introduction across VPDs at a ‘global level’ (Gavi-supported countries) was 5.4 years. Once licensed, MenA vaccines reached first introduction fastest (campaign=0.6 years; routine immunisation (RI)=1.7 years). Most introductions were delayed. Country uptake following first introduction was accelerated for more recently Gavi-supported RI vaccines compared with older ones.ConclusionFactors accelerating timelines across delivery platforms included rapid product prequalifications by WHO, strong initial recommendations by the WHO Strategic Advisory Group of Experts (SAGE) on Immunization, achieving target product profiles on first vaccine licensure within a VPD and completing several VPD milestones at a global level prior to licensure. Milestones required for introduction in Gavi-supported countries should start prior or in parallel to licensure to accelerate uptake of vaccines delivered through diverse delivery platforms.

Mammalian expression of virus-like particles as a proof of principle for next generation polio vaccines

Global vaccination programs using live-attenuated oral and inactivated polio vaccine (OPV and IPV) have almost eradicated poliovirus (PV) but these vaccines or their production pose significant risk in a polio-free world. Recombinant PV virus-like particles (VLPs), lacking the viral genome, represent safe next-generation vaccines, however their production requires optimisation. Here we present an efficient mammalian expression strategy producing good yields of wild-type PV VLPs for all three serotypes and a thermostabilised variant for PV3. Whilst the wild-type VLPs were predominantly in the non-native C-antigenic form, the thermostabilised PV3 VLPs adopted the native D-antigenic conformation eliciting neutralising antibody titres equivalent to the current IPV and were indistinguishable from natural empty particles by cryo-electron microscopy with a similar stabilising lipidic pocket-factor in the VP1 β-barrel. This factor may not be available in alternative expression systems, which may require synthetic pocket-binding factors. VLPs equivalent to these mammalian expressed thermostabilized particles, represent safer non-infectious vaccine candidates for the post-eradication era.

An experience of mass administration of fractional dose inactivated polio vaccine through intradermal needle-free injectors in Karachi, Sindh, Pakistan

Background Inactivated Polio Vaccine (IPV) campaign was conducted in February 2019 in Karachi where needle-free injectors were introduced for the administration of the fractional dose of IPV (fIPV) on a large scale. This study aimed to determine the impact of needle-free injectors on vaccination coverage. Methods In four towns of Karachi, fIPV was given using needle-free injectors “PharmaJet Tropis ID”. Whereas, in six towns full dose of IPV was administered to children of 4–59 months of age. Cluster surveys through rapid convenience assessment method were conducted after the completion of vaccination activity. Results A total of 33,815 households’ data was analyzed. Among these, 27,650 (82.8%) children were vaccinated. In fIPV areas, 85.3% of children were vaccinated compared to 79.5% in full dose IPV areas. A comparison of reasons for unvaccinated showed that 1.6% of parents do not give importance to vaccination in fIPV areas compared to 4.2% in full IPV areas (p-value < 0.0001). More children were not vaccinated due to fear of injection 1.8% in full IPV areas compared to 0.7% in fIPV areas (p-value < 0.0001). The source of campaign information shows that more frequent mobile miking 3.1% was observed in fIPV areas compared to 0.4% in full IPV areas (p-value < 0.0001). Conclusions Our analysis supports the fractional dose of IPV in mass campaigns to achieve good vaccination coverage especially using needle-free injectors “PharmaJet Tropis ID” and vigorous social mobilization activities are expedient in accomplishing high coverage.

The Pathology of Poliomyelitis and the Vaccines and Nonvaccine Therapy

Poliomyelitis is an exclusively human disease that mainly affects children. Clinical features of poliomyelitis can be varied, from mild illness to the most severe paralysis, and the factor why poliomyelitis has different performances in individuals has been proved strongly correlated with membrane protein CD155. The nervous system shows a special protecting phenomenon against the invasion of poliovirus, and the mechanism is not very clear at present. Vaccines are the main means of preventing and controlling polio, and many different vaccines have been invented in the process of fighting polio. Inactivated polio vaccine (IPV) and oral polio vaccine (OPV) are the two main vaccines. IPV is known for its safety while OPV is widely used in developing countries because of its relatively low cost. This usage also leads to some side effects: vaccine-associated paralytic polio (VAPP) and vaccine-derived poliovirus (VDPV). Now, for polio eradication, the elimination of these two diseases has become particularly important. Thus, a new type of vaccine was created: sequential IPV-OPV with the safety of IPV and the low cost of OPV. This paper will talk about the different polio vaccines and their effects. An enormous difference between people who have gotten the vaccine and people who have not got the vaccine. Comparing the two kinds of people, people who get normal poliovirus, and people who get poliovirus after taking a vaccine, known as VAPP (vaccine-associated paralytic poliomyelitis), the former cannot get full recovery whole life and the latter has a very low possibility. In conclusion, people should take vaccines if it is affordable for them.

PREVALENCE OF NEUTRALIZING ANTIBODIES AGAINST POLIOVIRUS 1, 2, AND 3 IN HEALTHCARE PROFESSIONALS AGED 20-50 YEARS

ABSTRACT Objective: To describe the prevalence of neutralizing antibodies against poliovirus (PV1, PV2, and PV3) in blood samples of healthcare professionals aged 20 to 50 years. Methods: Health professionals who serve children at Darcy Vargas Children’s Hospital and the Department of Pediatrics of Irmandade da Santa Casa de São Paulo. The sample size was calculated at 323 participants. The Mantel-Haenszel chi-square was used to verify differences between groups. The neutralization reaction detected human poliovirus antibodies. For susceptible individuals, vaccination with the inactivated+triple acellular polio vaccine was performed, and neutralizing antibodies were re-dosed after one week. Results: 333 professionals were studied - 92.8% were immune to poliovirus 1, 86.5% to poliovirus 2, and 63.3% to poliovirus 3; 37% had titers less than 1:8 for any serotype, 5;1% had titers below 1:8 for all three. Vaccination with inactivated polio vaccine was performed for susceptible participants, and neutralizing antibodies were dosed after one week, showing increased titers for all polioviruses. Conclusions: Despite the detection of a significant percentage of individuals with low poliovirus antibody titer, the challenge with vaccination demonstrated immune response compatible with poliovirus immunity.