Immunogenicity and Safety of Inactivated Sabin-Strain Polio Vaccine “PoliovacSin”: Clinical Trials Phase I and II

Global polio eradication requires both safe and effective vaccines, and safe production processes. Sabin oral poliomyelitis vaccine (OPV) strains can evolve to virulent viruses and result in poliomyelitis outbreaks, and conventional inactivated poliomyelitis vaccine (Salk-IPV) production includes accumulation of large stocks of neurovirulent wild polioviruses. Therefore, IPV based on attenuated OPV strains seems a viable option. To increase the global supply of affordable inactivated vaccine in the still not-polio free world we developed an IPV made from the Sabin strains–PoliovacSin. Clinical trials included participants 18–60 years of age. A phase I single-center, randomized, double-blind placebo-controlled clinical trial included 60 participants, who received one dose of PoliovacSin or Placebo. A phase II multicenter, randomized, double-blind, comparative clinical trial included 200 participants, who received one dose of PoliovacSin or Imovax Polio. All vaccinations were well tolerated, and PoliovacSin had a comparable safety profile to the Placebo or the reference Imovax Polio preparations. A significant increase in neutralizing antibody levels to polioviruses types 1–3 (Sabin and wild) was observed in PoliovacSin and Imovax Polio vaccinated groups. Therefore, clinical trials confirmed good tolerability, low reactogenicity, and high safety profile of the PoliovacSin and its pronounced immunogenic properties. The preparation was approved for clinical trials involving infants.

Assessment of Preventative Measures Practice among Umrah Pilgrims in Saudi Arabia, 1440H-2019

Background: Annually, approximately 10 million pilgrims travel to the Kingdom of Saudi Arabia (KSA) for Umrah from more than 180 countries. This event presents major challenges for the Kingdom’s public health sector, which strives to decrease the burden of infectious diseases and to adequately control their spread both in KSA and pilgrims home nations. The aims of the study were to assess preventative measures practice, including vaccination history and health education, among Umrah pilgrims in Saudi Arabia. Methods: A cross sectional survey was administered to pilgrims from February to April 2019 at the departure lounge at King Abdul Aziz International airport, Jeddah city. The questionnaire comprised questions on sociodemographic information (age, gender, marital status, level of education, history of vaccinations and chronic illnesses), whether the pilgrim had received any health education and orientation prior to coming to Saudi Arabia or on their arrival, and their experiences with preventative practices. Results: Pilgrims (n = 1012) of 41 nationalities completed the survey. Chronic diseases were reported among pilgrims (n = 387, 38.2%) with cardiovascular diseases being the most reported morbidity (n = 164, 42.3%). The majority of pilgrims had been immunized prior to travel to Saudi Arabia (n = 770, 76%). The most commonly reported immunizations were influenza (n = 514, 51%), meningitis (n = 418, 41%), and Hepatitis B virus vaccinations (n = 310, 31%). However, 242 (24%) had not received any vaccinations prior to travel, including meningitis vaccine and poliomyelitis vaccine, which are mandatory by Saudi Arabian health authorities for pilgrims coming from polio active countries. Nearly a third of pilgrims (n = 305; 30.1%) never wore a face mask in crowded areas during Umrah in 2019. In contrast, similar numbers said they always wore a face mask (n = 351, 34.6%) in crowded areas, while 63.2% reported lack of availability of face masks during Umrah. The majority of participants had received some form of health education on preventative measures, including hygiene aspects (n = 799, 78.9%), mostly in their home countries (n = 450, 44.4%). A positive association was found between receiving health education and practicing of preventative measures, such as wearing face masks in crowded areas (p = 0.04), and other health practice scores (p = 0.02). Conclusion: Although the experiences of the preventative measures among pilgrims in terms of health education, vaccinations, and hygienic practices were at times positive, this study identified several issues. These included the following preventative measures: immunizations, particularly meningitis and poliomyelitis vaccine, and using face masks in crowded areas. The recent COVID-19 pandemic highlights the need for further studies that focus on development of accessible health education in a form that engages pilgrims to promote comprehensive preventative measures during Umrah and Hajj and other religious pilgrimages.

Polio vaccination coverage among children aged 12-23 months in a health block in North Kerala

Background: Polio (poliomyelitis) is a highly infectious viral disease which affects the nervous system and can result in irreversible paralysis within hours. There is no cure for polio, hence it becomes necessary to prevent the disease through vaccination. Thus, the objective of this study was to evaluate the polio vaccination coverage among children aged 12-23 months in a health block in Kannur, North Kerala.Methods: A community based cross sectional study was conducted among the children in the age group of 12-23 months residing in Pappinisseri block of Kannur district. Stratified random sampling was used. The details of 321 children were obtained using a pre-tested semi-structured questionnaire. The data was entered into Microsoft Excel 2007 spread sheet and analyzed using SPSS version 16.0 software.Results: Of the 321 children, males constituted 173 (54%) and females constituting 148 (46%). The total coverage of oral polio vaccines (OPV) (considering OPV-0, 1st, 2nd and 3rd doses) was found to be 92.8% and the inactivated poliomyelitis vaccine (IPV) coverage (IPV 1st and 2nd doses) to be 90.7%. Also, majority of the respondents were unaware of the use of OPV and IPV vaccines in the UIP.Conclusions: In spite of the efforts taken by the Government and the health officials, the OPV and IPV coverage has not reached 100% and also, the knowledge of mothers regarding the diseases prevented by the vaccines were very low. The reasons for this needs to be further evaluated.

Vaccine-Associated Neurological Adverse Events: A Case Report and Literature Review

Vaccination is an effective strategy to reduce the burden of preventable illness. However, many clinical reports revealed that various vaccinations may associate with neurological disorders, mainly including autoimmune disease, febrile seizure, and vaccine-associated paralytic poliomyelitis (VAPP). Although more and more reports revealed that part of the above post-vaccine neurological disorders is not directly related to vaccination, it may be merely a coincidence. However, these reports may increase the hesitancy on vaccination for the public population and influence the coverage of vaccination. In this report, we described a child with acute flaccid paralysis possibly caused by a poliovirus vaccine. To provide feasible ways to realize or reduce the risk of neurological adverse events caused by vaccines, we further provide a mini-review of the literature of vaccination associated with neurological adverse events. This revealed that oral poliomyelitis vaccine use exclusively and type 2 serotype poliomyelitis vaccine virus were the risk factors for VAPP. The combination vaccine was associated with an increased risk of ADEM and FS following immunization when compared with the administration of vaccines separately. Even though cases have been reported that vaccination may be a trigger of anti-NMDARe and GBS, there is no direct evidence to prove that vaccination increased the risk of GBS and anti-NMDARe.