Real-world data on immune responses following heterologous prime-boost COVID-19 vaccination schedule with Pfizer and AstraZeneca vaccines in England

Background There are limited data on immune responses to heterologous COVID–19 immunisation schedules, especially following an extended ≥12–week interval between doses. Methods SARS–CoV–2 infection–naïve and previously–infected adults receiving ChAd–BNT (ChAdOx1 nCoV–19, AstraZeneca followed by BNT162b2, Pfizer–BioNTech) or BNT–ChAd as part of the UK national immunisation programme provided blood samples at 30 days and 12 weeks after their second dose. Geometric mean concentrations (GMC) of anti–SARS–CoV–2 spike (S-antibody) and nucleoprotein (N-antibody) IgG antibodies and geometric mean ratios (GMR) were compared with a contemporaneous cohort receiving homologous ChAd–ChAd or BNT–BNT. Results During March–October 2021, 75,827 individuals were identified as having received heterologous vaccination, 9,489 invited to participate, 1,836 responded (19.3%) and 656 were eligible. In previously–uninfected adults, S–antibody GMC at 30 days post–second dose were lowest for ChAd–ChAd (862 (95%CI, 694– 1069)) and significantly higher for ChAd–BNT (6233 (5522– 7035); GMR 6.29; (5.04– 7.85); p<0.001), BNT-ChAd (4776 (4066– 5610); GMR 4.55 (3.56– 5.81); p<0.001) and BNT–BNT (5377 (4596– 6289); GMR 5.66 (4.49– 7.15); p<0.001). By 12 weeks after dose two, S–antibody GMC had declined in all groups and remained significantly lower for ChAd–ChAd compared to ChAd–BNT (GMR 5.12 (3.79– 6.92); p<0.001), BNT–ChAd (GMR 4.1 (2.96– 5.69); p<0.001) and BNT–BNT (GMR 6.06 (4.32– 8.50); p<0.001). Previously infected adults had higher S–antibody GMC compared to infection–naïve adults at all time–points and with all vaccine schedules. Conclusions These real–world findings demonstrate heterologous schedules with adenoviral–vector and mRNA vaccines are highly immunogenic and may be recommended after a serious adverse reaction to one vaccine product, or to increase programmatic flexibility where vaccine supplies are constrained.

Rotavirus Genotypes in Abuja, Nigeria

Introduction: Nigeria had planned to introduce the rotavirus vaccine in the National Immunisation Programme in 2014, but this has yet to be done. Nigeria has the continent's highest mortality due to diarrhoeal diseases with little information on specific, prevalent genotypes. Aim: The study's main objectives were to identify the predominant rotavirus genotypes and examine the effects of existing local vaccination programs on prevailing rotavirus genotypes and on preventing rotavirus diarrhoea. Methodology: A one-year prospective descriptive study of children under 5 with acute diarrhoea was conducted from June 2018 to May 2019. Children with acute diarrhoea attending Asokoro District Hospital, Abuja. Children without diarrhoea were also recruited as a control group. Rotavirus ELISA and RNA extraction were done with commercially available kits, and positive samples were subjected to RT-PCR and electrophoresis to determine VP7 (G) and VP4 (P) genotypes. Results: Rotavirus-ELISA was positive among 231 (17.8%) children with diarrhoea and 29 (2.2%) of controls, with November, December. The predominant VP7 genotypes was G1 (n=116, 50.2%) followed by G9 (n=66, 28.5%). Viral Protein, VP4 (P) was mostly P [8] (n=143, 74.8%) followed by P [4] (n=21, 10.9%). The predominant genotype combinations found were G1 P [8] (n=108, 46.7%), G9 P [8] (n=62, 26.8%), and G2 P [4] (n=18, 7.7%). Very few mixed infections were found in the study, 2 (0.8%). Among 94 unvaccinated children with rotavirus isolates that were genotyped, G1 P [8] (n=88, 49.4%) and G9 P [8] (n=43, 24.1%) were predominant. Among 32 vaccinated children, G1 P [8] (n=13, 40.2%) and G9 P [8] (n=9, 28.1%) were predominant. Conclusion: The emergence of new genotypes such as G 12 P [4] found in this study emphasize the need for continued prospective monitoring of rotavirus at the molecular level to detect new threats to vaccine programs in future.

Trust in Government and Covid-19 Vaccine Hesitancy

The long-term success of New Zealand’s Covid-19 elimination plan and the re-opening of fortress New Zealand rests on high population uptake of the Covid-19 vaccine. Understanding factors that contribute to vaccine hesitancy – and potential inequities in access and uptake – are consequently essential for the efficacy of the national immunisation programme which began rolling out to the general population in July 2021. Prior research on the New Zealand context has documented socio-demographic disparities in Covid-19 vaccine hesitancy (Horizon Research, 2020; Prickett, Habibi and Atatoa Carr, 2021; Thaker, 2021). However, little research has been undertaken to examine how psychosocial elements – such as people’s trust in institutions – might be associated with people’s vaccine intent and cast some light on the reasons underpinning their intent.

Vaccination In Pregnancy Against Pertussis And Seasonal Influenza: Key Learnings And Components From High-Performing Vaccine Programmes In Three Countries: United Kingdom, The United States And Spain

Background: Pertussis and seasonal influenza are responsible for significant maternal, neonatal, and infant morbidity and mortality, but vaccine coverage rates (VCR) for both pertussis (administered as a tetanus, diphtheria, acellular pertussis [Tdap] vaccination) and seasonal influenza in pregnancy remain generally low. Only a small number of countries, including Spain, the United Kingdom (UK), and the United States of America (USA), have high Tdap and seasonal influenza VCRs in pregnancy. The purpose of this study was to identify the key factors that contributed to the high VCRs observed in these countries.Methods: The experience from both Tdap and seasonal influenza vaccination programmes during pregnancy were documented in Spain, the UK, and the USA using a three-step approach. A literature review yielded 157 publications, and a further 117 documents were selected through desk research. A published five-pillar VCR framework for influenza was amended to evaluate the specific contributing factors leading to high Tdap and seasonal influenza VCRs among pregnant women.Results: The analysis identified components that contributed to higher VCR in pregnant women across three different healthcare systems in Spain, UK, and USA. The combination of several key interventions in each country led to a rapid increase in VCR that reached near-optimal levels (i.e. 75% for seasonal influenza) within a few years. As well as inclusion in national immunisation programme and vaccine reimbursement, key components that were identified included the mobilisation of health authorities, prenatal care Healthcare Professionals (HCP) and scientific societies, the inclusion of vaccination in antenatal medical guidance, the provision of educational material to HCPs, and a strong disease awareness driven by recent pertussis outbreaks in each country.Conclusions: Although there is no simple, universal solution to improving sub-optimal VCRs, the list of components identified in this study from three countries with high-performing Tdap and seasonal influenza vaccination programmes provides a basis for public health and medical stakeholders in other countries to define strategies to successfully implement national vaccination programmes for pregnant women.

Serotype distribution of invasive, non-invasive and carried Streptococcus pneumoniae in Malaysia: a meta-analysis

Background Pneumococcal pneumonia is the leading cause of under-five mortality globally. The surveillance of pneumococcal serotypes is therefore vital for informing pneumococcal vaccination policy and programmes. Pneumococcal conjugate vaccines (PCVs) have been available as an option in the private healthcare setting and beginning December 2020, PCV10 was incorporated as part of routine national immunisation programme (NIP) in Malaysia. We searched existing literature on pneumococcal serotype distribution across Malaysia to provide an overall view of this distribution before the implementation of PCV10. Methods Online databases (PubMed, Ovid MEDLINE and Scopus), reference lists of articles identified, and grey literature (Malaysian Ministry of Health website, WHO website) were systematically searched for relevant literature on pneumococcal serotype distribution across Malaysia up to 10th November 2020. No lower date limit was set to maximise the number of target reports returned. Results of serotypes were split by age categories, including ≤5 years, > 5 years and unreported for those that did not specify. Results The search returned 18 relevant results, with a total of 2040 isolates. The most common serotypes across all disease types were 19F (n = 313, 15.3% [95%CI: 13.8–17.0]), 23F (n = 166, 8.1% [95%CI: 7.0–9.4]), 14 (n = 166, 8.1% [95%CI: 7.0–9.4]), 6B (n = 163, 8.0% [95%CI: 6.9–9.2]) and 19A (n = 138, 6.8% [95%CI: 5.8–7.9]). Conclusion Four of the most common serotypes across all isolate sources in Malaysia are covered by PCV10, while PCV13 provides greater serotype coverage in comparison to PCV10. There is still a need for surveillance studies, particularly those investigating serotypes in children under 5 years of age, to monitor vaccine effectiveness and pneumococcal population dynamic following implementation of PCV10 into routine immunisation.

Health System Barriers and Facilitators to Delivering Additional Vaccines through the National Immunisation Programme in China: A Qualitative Study of Provider and Service-User Perspectives

In China, there are two categories of vaccines available from the Chinese Center for Disease Control and associated public health agencies. Extended Program of Immunization (EPI) vaccines are government-funded and non-EPI vaccines are voluntary and paid for out-of-pocket. The government plans to transition some non-EPI vaccines to EPI in the coming years, which may burden public health system capacity, particularly in terms of budget, workforce, supply chains, and information systems. Our study explored vaccinator and caregiver perspectives on introducing non-EPI vaccines into routine immunization and perceived facilitators and barriers affecting this transition. We conducted a qualitative study from a realist perspective, analysing semi-structured interviews with 26 vaccination providers and 160 caregivers in three provinces, selected to represent regional socioeconomic disparities across Eastern, Central, and Western China. Data were analysed thematically, using deductive and inductive coding. Most participants were positive about adding vaccines to the national schedule. Candidate EPI vaccines most frequently recommended by participants were varicella, mumps vaccine, and hand–foot–mouth disease. Providers generally considered existing workspaces, cold-chain equipment, and funding sufficient, but described frontline staffing and vaccine information systems as requiring improvement. This is the first qualitative study to explore interest, barriers, and facilitators related to adding vaccines to China’s national schedule from provider and caregiver perspectives. Findings can inform government efforts to introduce additional vaccines, by including efforts to retain and recruit vaccine programme staff and implement whole-process data management and health information systems that allow unified nationwide data collection and sharing.

Carriage of upper respiratory tract pathogens in rural communities of Sarawak, Malaysian Borneo

Introduction Pneumonia is a leading cause of death in Malaysia. Whilst many studies have reported the aetiology of pneumonia in Western countries, the epidemiology of pneumonia in Malaysia remains poorly understood. As carriage is a prerequisite for disease, we sought to improve our understanding of the carriage and antimicrobial resistance (AMR) of respiratory tract pathogens in Malaysia. The rural communities of Sarawak are an understudied part of the Malaysian population and were the focus of this study, allowing us to gain a better understanding of bacterial epidemiology in this population. Methods A population-based survey of bacterial carriage was undertaken in participants of all ages from rural communities in Sarawak, Malaysia. Nasopharyngeal, nasal, mouth and oropharyngeal swabs were taken. Bacteria were isolated from each swab and identified by culture-based methods and antimicrobial susceptibility testing conducted by disk diffusion or E test. Results 140 participants were recruited from five rural communities. Klebsiella pneumoniae was most commonly isolated from participants (30.0%), followed by Staphylococcus aureus (20.7%), Streptococcus pneumoniae (10.7%), Haemophilus influenzae (9.3%), Moraxella catarrhalis (6.4%), Pseudomonas aeruginosa (6.4%) and Neisseria meningitidis (5.0%). Of the 21 S. pneumoniae isolated, 33.3 and 14.3% were serotypes included in the 13 valent PCV (PCV13) and 10 valent PCV (PCV10) respectively. 33.8% of all species were resistant to at least one antibiotic, however all bacterial species except S. pneumoniae were susceptible to at least one type of antibiotic. Conclusion To our knowledge, this is the first bacterial carriage study undertaken in East Malaysia. We provide valuable and timely data regarding the epidemiology and AMR of respiratory pathogens commonly associated with pneumonia. Further surveillance in Malaysia is necessary to monitor changes in the carriage prevalence of upper respiratory tract pathogens and the emergence of AMR, particularly as PCV is added to the National Immunisation Programme (NIP).

Seroprevalence of meningococcal serogroup C bactericidal antibodies in the Portuguese population, a decade after vaccine introduction in the National Immunisation Programme

Background The incidence of invasive meningococcal disease due to serogroup C (MenC) decreased in Portugal since the introduction of the conjugate vaccine (MCC) in the free market in 2001 and in the National Immunisation Plan in 2006. Considering the potential waning of the antibody response reported in the literature, the different vaccination schemes that were used in our country over the past decade, and that Neisseria meningitidis serogroup C continues to circulate, the Portuguese population may currently be at increased risk of infection. In the absence of national data, we evaluated the seroprotection level of the Portuguese population against MenC, in order to identify the protected fraction of the population and ponder on the necessity of a booster dose of the MCC vaccine. Methods We measured serum bactericidal antibody levels against MenC in a representative sample of the population (n = 1500) aged 2–64 years who participated in the 2015/2016 National Serological Survey. Results A total of 31.1% (466/1500, 95%CI: 29–33%) of the individuals studied were protected against MenC. The geometric mean titre was 6.5. The proportion of seroprotected was particularly low in children aged 2–4 years (<16%) who received a single dose of the vaccine at 12 months of age (vaccination strategy since 2012). The proportion of seroprotected was higher (44.7% to 53.5%) in adolescent and young adults (15–24 years of age), resulting from vaccination during the catch-up campaign at 5–15 years of age. The highest protection rates were observed when the vaccine was administered during adolescence. Conclusion The small fraction of population seroprotected, combined with the already known waning effect of the antibody response over time, may indicate that the Portuguese population will become progressively more exposed to the risk of infection. Taking in consideration our results, we recommend to change the current vaccination strategy and introduce a booster dose of the MCC vaccine during adolescence.

Multicenter prospective surveillance study of viral agents causing meningoencephalitis

The frequency of bacterial factors causing central nervous system infections has decreased as a result of the development of our national immunization program. In this study, it is aimed to obtain the data of our local surveillance by defining the viral etiology in cases diagnosed with meningoencephalitis for 1 year. Previously healhty 186 children, who applied with findings suggesting viral meningoencephalitis to 8 different tertiary health centers between August 2018 and August 2019, in Istanbul, were included. The cerebrospinal fluid (CSF) sample was evaluated by polymerase chain reaction. The M:F ratio was 1.24 in the patient group, whose age ranged from 1 to 216 months (mean 40.2 ± 48.7). Viral factor was detected in 26.8%. Enterovirus was the most common agent (24%) and followed by Adenovirus (22%) and HHV type 6 (22%). In the rest of the samples revealed HHV type 7 (10%), EBV (6%), CMV (6%), HSV type 1 (6%), Parvovirus (4%) and VZV (2%). The most common symptoms were fever (79%) and convulsions (45.7%). Antibiotherapy and antiviral therapy was started 48.6% and 4% respectively. Mortality and sequela rate resulted 0.53% and 3.7%, respectively. This highlights the importance of monitoring trends in encephalitis in Turkey with aview to improving pathogen diagnosis for encephalitis and rapidly identifying novel emerging encephalitis-causing pathogens that demand public health action especially in national immunisation programme.