Persistence of IgM Antibodies after Vaccination with Live Attenuated Japanese Encephalitis Vaccine

Association of Lung Fibrotic Changes and Cardiological Dysfunction with Comorbidities in Long COVID-19 Cohort

Background. Long COVID-19 symptoms appeared in many COVID-19 survivors. However, the prevalence and symptoms associated with long COVID-19 and its comorbidities have not been established. Methods. In total, 312 patients with long COVID-19 from 21 primary care centers were included in the study. At the six-month follow-up, their lung function was assessed by computerized tomography (CT) and spirometry, whereas cardiac function was assessed by elec-trocardiogram (ECG), Holter ECG, echocardiography, 24 h blood pressure monitoring, and a six-minute walk test (6MWT). Results. Of the 312 persons investigated, significantly higher sys-tolic and diastolic blood pressure, left ventricular hypertrophy, and elevated NT-proBNP were revealed in participants with hypertension or type 2 diabetes. Left ventricular diastolic dysfunc-tion was more frequently present in patients with hypertension. The most common registered CT abnormalities were fibrotic changes (83, 36.6%) and mediastinal lymphadenopathy (23, 10.1%). Among the tested biochemical parameters, three associations were found in long COVID-19 patients with hypertension but not diabetes: increased hemoglobin, fibrinogen, and ferritin. Nine patients had persisting IgM antibodies to SARS-CoV-2. Conclusions. We demon-strated a strong association between signs of cardiac dysfunction and lung fibrotic changes with comorbidities in a cohort of long COVID-19 subjects.

An evaluation of adverse events following an immunization campaign with the live, attenuated SA14-14-2 Japanese encephalitis vaccine in Cambodia

Introduction

Japanese encephalitis (JE) virus is the most common cause of vaccine-preventable encephalitis in Asia. The SA14-14-2 JE vaccine manufactured by Chengdu Institute of Biological Products has been shown to be safe and effective in clinical trials and childhood routine immunization programs. However, there are few published reports describing results of surveillance for adverse events following immunization (AEFI) when the vaccine is used in mass campaigns. We describe the results of AEFI surveillance following a 2013 vaccination campaign among almost 310,000 children aged 9 months–12 years in Battambang Province, Cambodia.

Methods

Routine AEFI surveillance was strengthened by staff training and supplemented by active hospital surveillance. An AEFI was defined as any sign, symptom, or disease temporally associated (i.e., within 4 weeks) with receipt of the vaccine, irrespective of whether it was considered related to immunization. Data were collected on standardized forms and causality assessments were conducted for serious AEFI.

Results

Passive and active surveillance detected 28 AEFI for an overall incidence of 9.0 AEFI per 100,000 doses administered. The most frequent events were vasovagal episodes (n = 7, 25%) and rash (n = 6, 21%), and most other events were common childhood conditions such as fever and vomiting. Three AEFI were classified as serious, including one hypersensitivity reaction and two meningoencephalitis cases. Of these, the hypersensitivity event was the only serious AEFI classified as being consistent with a causal association to immunization.

Conclusions

Most reported adverse events were conditions that commonly occur after other childhood vaccinations or independently of vaccination, and in the context of careful monitoring for serious AEFI only one serious event consistent with a causal association with immunization was identified. These results support the good safety profile of the SA14-14-2 JE vaccine, and provide reassuring data as the vaccine’s use expands.

Immunoglobulin M seroneutralization for improved confirmation of Japanese encephalitis virus infection in a flavivirus-endemic area

BACKGROUND

The mainstay of diagnostic confirmation of acute Japanese encephalitis (JE) involves detection of anti-JE virus (JEV) immunoglobulin M (IgM) by enzyme-linked immunosorbent assay (ELISA). Limitations in the specificity of this test are increasingly apparent with the introduction of JEV vaccinations and the endemicity of other cross-reactive flaviviruses. Virus neutralization testing (VNT) is considered the gold standard, but it is challenging to implement and interpret. We performed a pilot study to assess IgG depletion prior to VNT for detection of anti-JEV IgM neutralizing antibodies (IgM-VNT) as compared with standard VNT.

METHODS

We evaluated IgM-VNT in paired sera from anti-JEV IgM ELISA-positive patients (JE n=35) and negative controls of healthy flavivirus-naïve (n=10) as well as confirmed dengue (n=12) and Zika virus (n=4) patient sera. IgM-VNT was subsequently performed on single sera from additional JE patients (n=76).

RESULTS

Anti-JEV IgG was detectable in admission serum of 58% of JE patients. The positive, negative and overall percentage agreement of IgM-VNT as compared with standard VNT was 100%. A total of 12/14 (86%) patient samples were unclassified by VNT and, with sufficient sample available for IgG depletion and IgG ELISA confirming depletion, were classified by IgM-VNT. IgM-VNT enabled JE case classification in 72/76 (95%) patients for whom only a single sample was available.

CONCLUSIONS

The novel approach has been readily adapted for high-throughput testing of single patient samples and it holds promise for incorporation into algorithms for use in reference centres.

The pig as an amplifying host for new and emerging zoonotic viruses

Pig production is a rapidly growing segment of the global livestock sector, especially in Asia and Africa. Expansion and intensification of pig production has resulted in significant changes to traditional pig husbandry practices leading to an environment conducive to increased emergence and spread of infectious diseases. These include a number of zoonotic viruses including influenza, Japanese encephalitis, Nipah and coronaviruses. Pigs are known to independently facilitate the creation of novel reassortant influenza A virus strains, capable of causing pandemics. Moreover, pigs play a role in the amplification of Japanese encephalitis virus, transmitted by mosquito vectors found in areas inhabited by over half the world's human population. Furthermore, pigs acted as an amplifying host in the first and still most severe outbreak of Nipah virus in Malaysia, that necessitated the culling over 1 million pigs. Finally, novel porcine coronaviruses are being discovered in high pig-density countries which have pandemic potential. In this review, we discuss the role that pigs play as intermediate/amplifying hosts for zoonotic viruses with pandemic potential and consider how multivalent vaccination of pigs could in turn safeguard human health.

The future of Japanese encephalitis vaccination: expert recommendations for achieving and maintaining optimal JE control

Vaccines against Japanese encephalitis (JE) have been available for decades. Currently, most JE-endemic countries have vaccination programs for their at-risk populations. Even so, JE remains the leading recognized cause of viral encephalitis in Asia. In 2018, the U.S. Centers for Disease Control and Prevention and PATH co-convened a group of independent experts to review JE prevention and control successes, identify remaining scientific and operational issues that need to be addressed, discuss opportunities to further strengthen JE vaccination programs, and identify strategies and solutions to ensure sustainability of JE control during the next decade. This paper summarizes the key discussion points and recommendations to sustain and expand JE control.