Human respiratory syncytial virus (RSV) is the leading cause of severe lower respiratory tract infection, such as bronchiolitis, bronchitis, or pneumonia, in both infants and the elderly. Despite the global burden of diseases attributable to RSV infection, no clinically approved vaccine is available, and a humanized monoclonal antibody for prophylaxis is not readily affordable in developing countries. There are several hurdles to the successful development of RSV vaccines: immune-vulnerable target populations such as premature infants, pregnant women, and immunocompromised people; safety concerns associated with vaccine-enhanced diseases; repeated infection; and waning memory. To develop successful strategies for the prevention of RSV infection, it is necessary to understand the protective and pathologic roles of host immune responses to RSV infection. In this review, we will summarize the positive and negative relationship between RSV infection and host immunity and discuss strategies for the development of the first successful RSV vaccine.
Humans ; Immunity ; Immunocompromised Host ; Respiratory Syncytial Virus Infections/immunology/*prevention & control ; *Respiratory Syncytial Virus Vaccines ; Respiratory Syncytial Viruses/*physiology

Humans ; Child ; Respiratory Syncytial Virus Infections/prevention & control*

Humans ; Respiratory Syncytial Virus Infections ; prevention & control ; therapy ; Respiratory Syncytial Viruses

The respiratory syncytial virus (RSV) belongs to the family Paramyxoviridae and subfamily Pneumovirinae. The RSV can cause acute infections of the lower respiratory tract in infants. The F gene of the RSV is a conservative gene and varies only slightly in its expression. Few studies focusing on the variability of the F gene have been carried out. F protein (fusion glycoprotein) is a transmembrane glycoprotein that mediates fusion and penetration between the virus and host cells. Neutralizing antibody against the F protein can protect against infection by RSV subtypes A and B. Hence, F protein has become the main target for the development of a monoclonal antibody and vaccine against the RSV. An effective vaccine is not available, so a monoclonal antibody against F protein is now the most important method to reduce the morbidity and severity associated with RSV infection in high-risk children. However, a monoclonal antibody can lead to the production of drug-resistant strains of the RSV. This review focuses on genetic variation of the F gene of the RSV as well as progress in the development of a monoclonal antibody against F protein and a vaccine in the last decade.
Animals ; Antibodies, Monoclonal ; immunology ; Humans ; Respiratory Syncytial Virus Infections ; immunology ; prevention & control ; virology ; Respiratory Syncytial Viruses ; genetics ; immunology ; Viral Fusion Proteins ; genetics ; immunology ; Viral Vaccines ; genetics ; immunology

To construct plasmid of recombinant protein candidate vaccine of respiratory syncytial virus, express it in E. coli, and to investigate its immunogenicity and protective efficacy. A CD8+ T cell epitope from respiratory syncytial virus (RSV) M2 protein F/M2:81 - 95 and the G:125-225 (G1) gene fragments from RSV-G protein containing B cell epitopes were amplified by PCR method and then inserted into the prokaryotic expression vector pET-DsbA after bonding to a linker. The fusion protein DsbA-G1-Linker-F/M2:81-95 (D-G1LF/M2) was expressed successfully in E. coli BL21 (DE3). The product was proved to be RSV-specific by Western-blot. After purified by affinity chromatography on Ni+ Sepharose and renatured by gradient dialysis. D-G1LF/M2 was used to immune BALB/c mice. D-G1LF/M2 induced high anti-D-G1LF/M2 IgG, anti-RSV IgG and neutralizing antibody titers in serum and lung of BALB/c mice, and elicied RSV-specific CTL responses. The IgG subclass distribution revealed that IgG1/IgG2a ratio was 2.66. Viral titration indicated that D-G1LF/M2 could protect BALB/c mice against RSV challenge in lung.
Animals ; Antibodies, Viral ; blood ; immunology ; Escherichia coli ; genetics ; metabolism ; Humans ; Immunoglobulin G ; blood ; immunology ; Mice ; Mice, Inbred BALB C ; Plasmids ; genetics ; immunology ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; Respiratory Syncytial Virus Infections ; prevention & control ; Respiratory Syncytial Virus Vaccines ; biosynthesis ; genetics ; immunology ; Respiratory Syncytial Virus, Human ; genetics ; immunology ; Viral Envelope Proteins ; genetics ; Viral Fusion Proteins ; genetics ; Viral Proteins ; genetics

RSV prophylaxis is not routine in infant born 33 to 35 weeks gestation. Risk scoring tool can be utilized to identify infants that have significant chance for hospitalization. Premature birth is a leading cause of infant mortality and chronic pulmonary morbidity, therefore prevention of RSV hospitalization though immune prophylaxis in late preterm infants appears attractive.
Antibodies, Monoclonal, Humanized ; therapeutic use ; Hospitalization ; Humans ; Infant, Newborn ; Infant, Premature ; Intensive Care Units, Neonatal ; Palivizumab ; Respiratory Syncytial Virus Infections ; prevention & control

OBJECTIVETo investigate the clinical epidemiologic characteristics and analyze risk factors for acute respiratory syncytial virus (RSV) infection in hospitalized infants with acute lower respiratory tract infection (ALRI).

METHODALRI infants admitted to Children's Hospital of Fudan University from March 1st, 2011 to February 29th, 2012, were enrolled in this study. Patient information included demographic characteristics, feeding history, family status, clinical presentation, accessory examination, treatment and prognosis. According to the etiology of ALRI infants, we compared the seasonal distribution, demographic characteristics, household characteristics and underlying diseases between RSV-positive patients and RSV-negative patients. Univariate and multiple Logistic regression analyses were used to determine factors that were associated with risk of RSV infection.

RESULTAmong 1 726 ALRI infants, there were 913 RSV-positive infants (52.9%). The occurrence of RSV infection had a seasonal variation, with a peak in winter (59.1%). The median (P25, P75) age of RSV infants was 64 (21-155) days. The gestational age (GA) and body weight (BW) was (37.5 ± 2.4) weeks and (3.07 ± 0.66) kg, respectively. The male/female ratio among these was 1.9: 1. RSV infection was more popular among infants in the families with smoking members, crowded living conditions, history of atopic mother. Differences of the proportion of patients with underlying disease between RSV-positive and negative groups were statistically significant (59.4% vs. 54.2%, P < 0.05). Univariate logistic regression demonstrated that factors increasing the risk of RSV infection were: GA<37 weeks (OR = 1.346, 95%CI: 1.037-1.748), birth weight <2 500 g (OR = 1.447, 95%CI: 1.103-1.898), underlying diseases (OR = 1.232, 95%CI: 1.018-1.492), underlying CHD (OR = 1.391, 95%CI: 1.120-1.728), environmental tobacco smoke exposure (OR = 1.254, 95%CI: 1.035-1.519), mother with atopic diseases (OR = 1.827, 95%CI: 1.296-2.573), crowded house with four or more than four family members (OR = 1.232, 95%CI: 1.013-1.498), autumn or winter infection (OR = 1.351, 95%CI: 1.024-1.783; OR = 1.713, 95%CI: 1.332-2.204). Multivariate logistic regression determined the factors increasing the risk of RSV infection were: underlying CHD (OR = 1.298, 95%CI: 1.002-1.681), mother with atopic diseases (OR = 1.766, 95%CI: 1.237-2.520), autumn or winter infection (OR = 1.481, 95%CI: 1.105-1.985; OR = 1.766, 95%CI: 1.358-2.296).

CONCLUSIONThe prevalence of RSV infection was the highest in winter, while preterm and low birth weight infants were more susceptible. Underlying diseases were found in 59.4% cases, CHD was the most common one. The factors increasing the risk of RSV infection were: CHD, mother with atopic diseases, autumn or winter infections.

Acute Disease ; China ; epidemiology ; Environmental Exposure ; adverse effects ; Female ; Hospitalization ; statistics & numerical data ; Humans ; Infant ; Infant, Newborn ; Logistic Models ; Male ; Prevalence ; Respiratory Syncytial Virus Infections ; epidemiology ; prevention & control ; Respiratory Syncytial Virus, Human ; isolation & purification ; Respiratory Tract Infections ; epidemiology ; prevention & control ; virology ; Retrospective Studies ; Risk Factors ; Seasons ; Socioeconomic Factors ; Tobacco Smoke Pollution

Anti-Asthmatic Agents ; therapeutic use ; Asthma ; physiopathology ; prevention & control ; therapy ; virology ; Child ; China ; Chronic Disease ; Cough ; physiopathology ; virology ; Drug Therapy, Combination ; Humans ; Respiratory Sounds ; drug effects ; physiopathology ; Respiratory Syncytial Virus Infections ; complications ; physiopathology ; prevention & control

Objective: To analyze the reasons for the fluctuations in the percentage of outpatient or emergency visits for influenza-like illness (ILI) during the Spring Festival and National Day in 2014-2018 surveillance season. Methods: ILI surveillance data was collected during the period of Spring Festival and National Day in mainland China, and downloaded from Chinese Influenza Surveillance Information System, during the 2014-2018 surveillance season. Results: There was no significant difference noticed in the number of ILI reports in the festival week with weeks before or after in both the southern and northern provinces. The number of outpatient visits was much less than that of the week before and after, but the number of emergency visits was statistically significantly increased. Conclusion: In the holiday peak of ILI%, the major causes was the impact of holiday-off at sentinel hospitals, resulting in a large reduction in the number of outpatient visits in the consulting room during the festivals.
Adolescent ; Adult ; Biometry ; Child ; Child, Preschool ; China/epidemiology* ; Disease Outbreaks/prevention & control* ; Emergency Service, Hospital/statistics & numerical data* ; Holidays ; Hospitals ; Humans ; Influenza, Human/virology* ; Outpatients/statistics & numerical data* ; Population Surveillance ; Respiratory Syncytial Virus Infections/virology* ; Respiratory Syncytial Virus, Human/isolation & purification* ; Respiratory Tract Infections/virology* ; Seasons ; Young Adult

OBJECTIVETo describe the epidemiology and severity of illness of children hospitalized with respiratory syncytial virus (RSV) infection, including those who received palivizumab prophylaxis, at Royal University Hospital (RUH), Saskatoon and Regina General Hospital (RGH) from July 2002 to June 2005.

METHODSChildren hospitalized for ≥ 24 hours with laboratory-confirmed RSV infection were enrolled, and their health records were retrospectively reviewed for patient demographics and referral patterns, use of palivizumab prophylaxis, severity of infection (length of hospitalization, need for and duration of pediatric intensive care and mechanical ventilation) and outcome of infection.

RESULTSA total of 590 children (324 males) were hospitalized over the three years. The median chronological age at admission was 5.3 months, and median hospital stay was 4.0 days. Gestational age at birth was ≥ 36 weeks in 82.4% of patients. RSV disease severity was mild to moderate in 478 patients (81.0%) and severe in 110 (18.6%). Thirty-nine patients (6.6%) required pediatric intensive care unit admission, for a median of 5.0 days. Twenty-two of these patients (56%) were mechanically ventilated for a median of 6.0 days. Two children died, not attributed to RSV infection. Twenty-two patients had received palivizumab prophylaxis before hospital admission, with 18 completing at least 2 of the monthly doses. Most of these children (17/22) had mild to moderate illness.

CONCLUSIONSRSV causes significant morbidity in Saskatchewan, affecting predominantly term infants. The majority of illness is mild to moderate. Some patients who have received palivizumab may still develop significant RSV disease.

Adolescent ; Antibodies, Monoclonal, Humanized ; therapeutic use ; Child ; Child, Preschool ; Female ; Hospitalization ; Humans ; Infant ; Infant, Newborn ; Male ; Palivizumab ; Respiratory Syncytial Virus Infections ; epidemiology ; prevention & control ; Saskatchewan ; epidemiology ; Tertiary Care Centers ; Time Factors