Frequency of human papilomavirus and associated factors in gypsy and quilombola women : Human papillomavirus in gypsy and quilombola women.

BACKGROUND: The prevalence of Human Papillomavirus (HPV) infection in the general population is widely known, however, there are still few studies related to this infection in minority groups, Thus, the objective is to analyze the frequency of human papillomavirus and associated factors in quilombola and gypsy women. METHODS: Cross-sectional research with 145 quilombola and gypsy women from Caxias, Maranhão. Two Pap smear collections were performed and a questionnaire with 46 questions was applied between January, 2020 and March, 2021. Descriptive analysis and Odds Ratio with 95% confidence interval were performed. The research was approved by the ethics committee. RESULTS: There were 09 cases of atypia. The frequency of human papillomavirus was 41.37%, with a higher risk in quilombolas 55 (91.70%). Multiple infections were prevalent (53%) with high-risk genotypes 21 (35%). Types 16 and 18 together accounted for 42.85% of cases. CONCLUSIONS: The frequency of human papillomavirus infection was higher than those recorded in the Northeast and Brazil, and therefore type 16 predominated. Due to limitations, the virus lineages and sublineages were not evaluated. Quilombola women had a higher rate of infection than gypsies.

Vaccination in Pediatric Patients with Sickle-Cell Disease: Uptake Report and Mini-Review.

BACKGROUND: Brazil has one of the highest numbers of births with sickle-cell disease (SCD) in the Americas. Despite the risk of severe illnesses and death due to both vaccine-preventable infections, vaccination uptake in pediatric patients with SCD is unknown. MATERIAL AND METHODS: Children under 18 years with SCD presenting to routine medical consultations had their vaccination status evaluated according to the national recommendations. Data obtained were classified as 'Adequate', 'Delayed' or 'Missing' vaccination and compared among age groups. RESULTS: From 117 children screened, 100 had their vaccination card available. Vaccination coverage of routine vaccines was above 95% for all primary series and both age groups, with varied rates of delays and low missing doses. Among SCD extended vaccination, the most frequently delayed and missed vaccines were those specifically recommended to individuals with SCD as per national guidelines-and particularly those against encapsulated bacteria. Significant and varied rates of missing doses occurred in primary series and booster doses for PPSV23, Hib, menC, hepatitis A and varicella. The average influenza vaccination rate was 69.5%, with higher rates among younger children. CONCLUSIONS: Children with SCD have alarming under-vaccination rates. Basic prevention strategies in Brazil should be reassessed in this specific population.

High prevalence of SARS-CoV-2 infection among symptomatic healthcare workers in a large university tertiary hospital in São Paulo, Brazil.

BACKGROUND: Brazil became the epicenter of the COVID-19 pandemic in Latin America since May 2020, reporting the highest number of cases and deaths in the region. Healthcare workers (HCWs) are at increased risk of SARS-CoV-2 infection, experiencing a significant burden from COVID-19. Identifying and understanding the clinical characteristics and risk factors associated with infection are of paramount importance to inform screening strategies and infection control practices in this scenario. The aims of this study were to investigate the prevalence and clinical characteristics of HCWs with COVID-19 symptoms. METHODS: Between March 21st and May 22nd, 2020 a cross-sectional study was performed in a tertiary university hospital in São Paulo. Prevalence of SARS-CoV-2 infection among HCWs with COVID-19 symptoms was determined by RT-PCR testing on nasopharyngeal and oropharyngeal samples. Participants were asked to complete an electronic structured questionnaire including clinical and demographic data. RESULTS: Overall, 125 (42.37%) of 295 symptomatic HCWs tested positive for SARS-CoV-2. Over the 10-week study period, positivity rates varied from 22.2% (95% CI 15.9-60.3%) in the second week to 55.9% (95% CI 43.2-68.6%) in the sixth week, reaching a plateau (38-46%) thereafter. Median (SD) age was 34.2 (9.9) years and 205 (69.5%) were female. We did not find significant differences in the prevalence of the most commonly reported underlying medical condition among healthcare workers that tested positive or negative for SARS-CoV-2 infection. After multivariable analysis, using logistic regression, anosmia (adjusted OR 4.4 95% CI 2.21-8.74) and ocular pain (adjusted OR 1.95 95% CI 1.14-3.33) were the only symptoms independently associated with positivity for SARS-CoV-2 infection. Follow-up information on clinical outcomes showed that 9 (7.2%) HCWs were hospitalized (seven were male) and 2 (1.6%) died. CONCLUSIONS: The findings of this study confirmed the high burden of SARS-CoV-2 infection among healthcare workers in the hardest hit city by the pandemic in Latin America. Anosmia and ocular pain were symptoms independently associated with COVID-19 diagnosis. In low and middle-income countries, where limited availability of tests is frequent, these findings may contribute to optimize a targeted symptom-oriented screening strategy.

Molecular characterisation of the NSP4 gene of group A human rotavirus G2P[4] strains circulating in São Paulo, Brazil, from 1994 and 2006 to 2010.

Group A human rotaviruses (HuRVA) are causative agents of acute gastroenteritis. Six viral structural proteins (VPs) and six nonstructural proteins (NSPs) are produced in RV-infected cells. NSP4 is a diarrhoea-inducing viral enterotoxin and NSP4 gene analysis revealed at least 15 (E1-E15) genotypes. This study analysed the NSP4 genetic diversity of HuRVA G2P[4] strains collected in the state of São Paulo (SP) from 1994 and 2006-2010 using reverse transcription-polymerase chain reaction, sequencing and phylogenetic analysis. Forty (97.6%) G2P[4] strains displayed genotype E2; one strain (2.4%) displayed genotype E1. These results are consistent with the proposed linkage between VP4/VP7 (G2P[4]) and the NSP4 (E2) genotype of HuRVA. NSP4 phylogenetic analysis showed distinct clusters, with grouping of most strains by their genotype and collection year, and most strains from SP were clustered together with strains from other Brazilian states. A deduced amino acid sequence alignment for E2 showed many variations in the C-terminal region, including the VP4-binding domain. Considering the ability of NSP4 to generate host immunity, monitoring NSP4 variations, along with those in the VP4 or VP7 protein, is important for evaluating the circulation and pathogenesis of RV. Finally, the presence of one G2P[4]E1 strain reinforces the idea that new genotype combinations emerge through reassortment and independent segregation.

Relative efficacy of AS03-adjuvanted pandemic influenza A(H1N1) vaccine in children: results of a controlled, randomized efficacy trial.

BACKGROUND: The vaccine efficacy (VE) of 1 or 2 doses of AS03-adjuvanted influenza A(H1N1) vaccine relative to that of 2 doses of nonadjuvanted influenza A(H1N1) vaccine in children 6 months to <10 years of age in a multinational study conducted during 2010-2011. METHODS: A total of 6145 children were randomly assigned at a ratio of 1:1:1 to receive 2 injections 21 days apart of A/California/7/2009(H1N1)-AS03 vaccine at dose 1 and saline placebo at dose 2, 2 doses 21 days apart of A/California/7/2009(H1N1)-AS03 vaccine (the Ad2 group), or 2 doses 21 days apart of nonadjuvanted A/California/7/2009(H1N1) vaccine (the NAd2 group). Active surveillance for influenza-like illnesses continued from days 14 to 385. Nose and throat samples obtained during influenza-like illnesses were tested for A/California/7/2009(H1N1), using reverse-transcriptase polymerase chain reaction. Immunogenicity, reactogenicity, and safety were assessed. RESULTS: There were 23 cases of confirmed 2009 pandemic influenza A(H1N1) (A[H1N1]pdm09) infection for the primary relative VE analysis. The VE in the Ad2 group relative to that in the NAd2 group was 76.8% (95% confidence interval, 18.5%-93.4%). The benefit of the AS03 adjuvant was demonstrated in terms of the greater immunogenicity observed in the Ad2 group, compared with the NAd2 group. CONCLUSION: The 4-8-fold antigen-sparing adjuvanted pandemic influenza vaccine demonstrated superior and clinically important prevention of A(H1N1)pdm09 infection, compared with nonadjuvanted vaccine, with no observed increase in medically attended or serious adverse events. These data support the use of adjuvanted influenza vaccines during influenza pandemics. Clinical Trials Registration. NCT01051661.

Carriage rate and effects of vaccination after outbreaks of serogroup C meningococcal disease, Brazil, 2010.

During 2010, outbreaks of serogroup C meningococcal (MenC) disease occurred in 2 oil refineries in São Paulo State, Brazil, leading to mass vaccination of employees at 1 refinery with a meningococcal polysaccharide A/C vaccine. A cross-sectional study was conducted to assess the prevalence of meningococci carriage among workers at both refineries and to investigate the effect of vaccination on and the risk factors for pharyngeal carriage of meningococci. Among the vaccinated and nonvaccinated workers, rates of overall meningococci carriage (21.4% and 21.6%, respectively) and of MenC carriage (6.3% and 4.9%, respectively) were similar. However, a MenC strain belonging to the sequence type103 complex predominated and was responsible for the increased incidence of meningococcal disease in Brazil. A low education level was associated with higher risk of meningococci carriage. Polysaccharide vaccination did not affect carriage or interrupt transmission of the epidemic strain. These findings will help inform future vaccination strategies.

Characteristics and clinical outcomes of COVID-19 in children: a hospital-based surveillance study in Latin America's hardest-hit city.

Background: In 2020, Brazil became the epicentre of the coronavirus disease (COVID-19) pandemic in Latin America, resulting in an unparalleled health catastrophe. Nevertheless, comprehensive clinical reports in Brazilian children are not available. Methods: This retrospective, hospital-based, active surveillance study was performed to identify paediatric patients with COVID-19 who presented at a private academic medical centre in a large urban area between March 2020 and March 2021. Clinical and demographic information was analysed for those requiring hospitalization, those with severe illness and those with clinical syndromes. Results: In total, 964 symptomatic cases were evaluated; of these, 17.7% required hospitalization, and 27.5% of hospitalized cases were classified as severe/critical. Acute bronchiolitis and pneumonia were the most common causes of hospitalization among the severe cases. Twenty-seven hospitalized children fulfilled the diagnostic criteria for multi-system inflammatory syndrome (median age 29 months; 85.2% cases were non-severe). A significant co-existing condition was present in 29% of hospitalized children. The risk of hospitalization was higher in children with at least one comorbidity, children aged <2 years and obese children. Increased risk of severe disease was described among those with leukopenia, leukocytosis or any significant comorbidity. No deaths occurred among the study population. Conclusion: Although most children with COVID-19 experienced mild disease, and no deaths occurred among the study population, a significant proportion of cases required hospitalization and developed severe illness. Obesity, young age, underlying comorbidity, leukopenia and leukocytosis were risk factors for hospitalization or severe disease.

Expert review of global real-world data on COVID-19 vaccine booster effectiveness and safety during the omicron-dominant phase of the pandemic.

INTRODUCTION: COVID-19 vaccines have been highly effective in reducing morbidity and mortality during the pandemic. However, the emergence of the Omicron variant and subvariants as the globally dominant strains have raised doubts about the effectiveness of currently available vaccines and prompted debate about potential future vaccination strategies. AREAS COVERED: Using the publicly available IVAC VIEW-hub platform, we reviewed 52 studies on vaccine effectiveness (VE) after booster vaccinations. VE were reported for SARS-CoV-2 symptomatic infection, severe disease and death and stratified by vaccine schedule and age. In addition, a non-systematic literature review of safety was performed to identify single or multi-country studies investigating adverse event rates for at least two of the currently available COVID-19 vaccines. EXPERT OPINION: Booster shots of the current COVID-19 vaccines provide consistently high protection against Omicron-related severe disease and death. Additionally, this protection appears to be conserved for at least 3 months, with a small but significant waning after that. The positive risk-benefit ratio of these vaccines is well established, giving us confidence to administer additional doses as required. Future vaccination strategies will likely include a combination of schedules based on risk profile, as overly frequent boosting may be neither beneficial nor sustainable for the general population.

Equity in vaccination policies to overcome social deprivation as a risk factor for invasive meningococcal disease.

INTRODUCTION: Social deprivation is associated with poorer healthcare access. Vaccination is among the most effective public health interventions and achieving equity in vaccination access is vitally important. However, vaccines are often reimbursed by public funds only when recommended in national immunization programs (NIPs), which can increase inequity between high and low socioeconomic groups. Invasive meningococcal disease (IMD) is a serious vaccination-preventable disease. This review focuses on vaccination strategies against IMD designed to reduce inequity. AREAS COVERED: We reviewed meningococcal epidemiology and current vaccination recommendations worldwide. We also reviewed studies demonstrating an association between social deprivation and risk of meningococcal disease, as well as studies demonstrating an impact of social deprivation on uptake of meningococcal vaccines. We discuss factors influencing inclusion of meningococcal vaccines in NIPs. EXPERT OPINION: Incorporating meningococcal vaccines in NIPs is necessary to reduce inequity, but insufficient alone. Inclusion provides clear guidance to healthcare professionals and helps to ensure that vaccines are offered universally to all target groups. Beyond NIPs, cost of vaccination should be reimbursed especially for disadvantaged individuals. These approaches should help to achieve optimal protection against IMD, by increasing access and immunization rates, eventually reducing social inequities, and helping to protect those at greatest risk.

According to the World Health Organization, health equity is achieved when every person has access to the highest attainable health standard regardless of socioeconomic status. Achieving health equity in access to vaccination is particularly important, as vaccination is one of the most effective public health measures. However, vaccines are often paid by public funds only when they are recommended in the country's National Immunization Program. This can increase inequity between the rich and poor, as people with fewer resources are less likely to have private insurance and be aware of vaccines that are not suggested by their doctor. Invasive meningococcal disease is uncommon and unpredictable but a serious infection that can result in long-term disability and can kill within 24 hours. Vaccination is the best measure to prevent it.We reviewed scientific studies to assess the link between socioeconomic status, the risk of having the disease, and the likelihood of being vaccinated against it. We found that the poorest households have the highest risk of getting the disease and the lowest vaccination rates, even in countries with successful vaccination programs.Achieving universal vaccination against invasive meningococcal disease is challenging for financial reasons and because the disease is uncommon. Key factors identified to improve vaccination uptake and reduce health inequity are the need for publicly funded vaccines, increased parents' knowledge of available vaccines, and stronger engagement of vaccination recommendation by doctors/nurses (see also Supplementary Figure 1).

Identifying the research, advocacy, policy and implementation needs for the prevention and management of respiratory syncytial virus lower respiratory tract infection in low- and middle-income countries.

Introduction: The high burden of respiratory syncytial virus (RSV) infection in young children disproportionately occurs in low- and middle-income countries (LMICs). The PROUD (Preventing RespiratOry syncytial virUs in unDerdeveloped countries) Taskforce of 24 RSV worldwide experts assessed key needs for RSV prevention in LMICs, including vaccine and newer preventive measures. Methods: A global, survey-based study was undertaken in 2021. An online questionnaire was developed following three meetings of the Taskforce panellists wherein factors related to RSV infection, its prevention and management were identified using iterative questioning. Each factor was scored, by non-panellists interested in RSV, on a scale of zero (very-low-relevance) to 100 (very-high-relevance) within two scenarios: (1) Current and (2) Future expectations for RSV management. Results: Ninety questionnaires were completed: 70 by respondents (71.4% physicians; 27.1% researchers/scientists) from 16 LMICs and 20 from nine high-income (HI) countries (90.0% physicians; 5.0% researchers/scientists), as a reference group. Within LMICs, RSV awareness was perceived to be low, and management was not prioritised. Of the 100 factors scored, those related to improved diagnosis particularly access to affordable point-of-care diagnostics, disease burden data generation, clinical and general education, prompt access to new interventions, and engagement with policymakers/payers were identified of paramount importance. There was a strong need for clinical education and local data generation in the lowest economies, whereas upper-middle income countries were more closely aligned with HI countries in terms of current RSV service provision. Conclusion: Seven key actions for improving RSV prevention and management in LMICs are proposed.

Zika virus outbreak in Brazil-Lessons learned and perspectives for a safe and effective vaccine.

Zika virus (ZIKV) is an emerging pathogen of public health concern, associated with a dramatic burden in places where the virus caused outbreaks between 2015 and 2017. In the Americas, the ZIKV was first reported in Brazil and rapidly spread through the Americas. Since its first report, a number of studies have been published as we continue to learn, not only about modes of transmission, but also clinical manifestations, risk of congenital anomalies, including microcephaly and neurological malformations in fetuses born from mothers infected during pregnancy. Interventions to reduce the burden of ZIKV infection are restricted to mosquito control, and for Aedes spp mosquitoes the strategies implemented to that end proved to be unsuccessful so far. Hence the lessons we can learn following the ZIKV epidemics become of paramount importance in the development of drug treatments and in search for a vaccine.

Vaccines and routine immunization strategies during the COVID-19 pandemic.

Severe acute respiratory syndrome coronavirus 2 related disease (COVID-19) is now responsible for one of the most challenging and concerning pandemics. By August 2020, there were almost 20 million confirmed cases worldwide and well over half-million deaths. Since there is still no effective treatment or vaccine, non-pharmaceutical interventions have been implemented in an attempt to contain the spread of the virus. During times of quarantine, immunization practices in all age groups, especially routine childhood vaccines, have also been interrupted, delayed, re-organized, or completely suspended. Numerous high-income as well as low- and middle-income countries are now experiencing a rapid decline in childhood immunization coverage rates. We will, inevitably, see serious consequences related to suboptimal control of vaccine-preventable diseases (VPDs) in children concurrent with or following the pandemic. Routine pediatric immunizations of individual children at clinics, mass vaccination campaigns, and surveillance for VPDs must continue as much as possible during pandemic.

Effectiveness of reaching and maintaining therapeutic hypothermia target temperature using low-cost devices in newborns with hypoxic-ischemic encephalopathy.

Therapeutic hypothermia (TH) using servo-controlled cooling devices has proved to be a safe and effective method to reduce mortality and sequelae in neonates with hypoxic-ischemic encephalopathy (HIE). However, such cooling devices can be expensive and have limited availability in low- and middle-income countries. To evaluate the feasibility and effectiveness of low-cost cooling devices (ice packs) to reach and maintain the target temperature in newborns with moderate or severe HIE. Descriptive retrospective cross-sectional study, including newborns with gestational age ≥35 weeks, weight ≥1800 g, with diagnosis of moderate or severe HIE, submitted to whole body hypothermia using ice packs for 72 hr. Data was obtained from medical records and databases. The thermal curves of each patient, time spent at the target temperature and rewarming time were evaluated. Complications directly related to therapeutic hypothermia, evolution, and early outcomes before hospital discharge were analyzed. Seventy-one newborns met the criteria for TH, and 61 completed the entire cooling period and were included in the final analysis. The average time to reach the target temperature was 1.50 ± 1.3 hr. The mean temperature during the cooling period was 33.5°C (±0.62). 82.32% of the measurements were within the target temperature range (from 33 to 34°C). The following adverse events were observed during TH: pulmonary hypertension 11.3%, arrhythmia 4.2%, and coagulopathy 26.7%. Whole body hypothermia using low-cost devices proved to be an effective method in the absence of availability of servo-controlled devices, representing a plausible option in restricted resource settings.

Systemic inflammatory syndrome in children during COVID-19 pandemic in Ceará state, northeastern Brazil: an observational study.

In this study, we report the occurrence of multisystemic inflammatory syndrome among 64 children (2 deaths) with recent severe acute respiratory syndrome-related coronavirus 2 (SARS-COV-2) infections in the northeast region of Brazil. The major clinical symptoms and signs reported were exanthema (60.9%), abdominal pain (56.3%), nausea and vomiting (46.9%), diarrhea (37.5%), and dyspnea (37.5%). Laboratory findings revealed that the levels of C-reactive protein (75.0%), hemoglobin (51.6%), D-dimer (48.4%), lymphocytes (43.8%), LDH (45.3%), AST (42.2%), ALT (51.6%), and ferritin (48.4%) were above the reference values for a given age and gender. The clinical findings were similar to those observed in Kawasaki disease, although it represents a separate entity, emphasizing the need for proactive surveillance and early treatment.

Multisystem inflammatory syndrome in children: a cross-sectional study of cases and factors associated with deaths during the COVID-19 pandemic in Brazil, 2020. / Síndrome inflamatória multissistêmica pediátrica: estudo seccional dos casos e fatores associados aos óbitos durante a pandemia de COVID-19 no Brasil, 2020.

OBJECTIVE: To characterize the clinical-epidemiological profile of multisystem inflammatory syndrome in children temporally associated with COVID-19 (MIS-C), and to identify factors associated with MIS-C deaths in Brazil, 2020. METHODS: This was a cross-sectional study, using national MIS-C monitoring data. Logistical regression was performed to estimate crude and adjusted odds ratios (OR). RESULTS: Median case (n=652) age was 5 years, 57.1% were male, 52.0% were of brown race/skin color and 6.4% died. Likelihood of death was greater among those who presented O2 saturation <95% (ORa=4.35 - 95%CI 1.69;11.20) and altered urea results (ORa=5.18 - 95%CI 1.91;14.04); likelihood of death was lower when red skin blotches were not present (ORa=0.23 - 95%CI 0.09;0.62), when anticoagulants were used (ORa=0.32 - 95%CI 0.12;0.89) and when immunoglobulins were used (ORa=0.38 - 95%CI 0.15;1.01). CONCLUSION: Fatality ratios were higher among cases that presented O2 saturation <95% and altered urea results. Fatality ratios were lower among those with red skin blotches, and those who used immunoglobulins and anticoagulants.

In Nasal Mucosal Secretions, Distinct IFN and IgA Responses Are Found in Severe and Mild SARS-CoV-2 Infection.

Likely as in other viral respiratory diseases, SARS-CoV-2 elicit a local immune response, which includes production and releasing of both cytokines and secretory immunoglobulin (SIgA). Therefore, in this study, we investigated the levels of specific-SIgA for SARS-CoV-2 and cytokines in the airways mucosa 37 patients who were suspected of COVID-19. According to the RT-PCR results, the patients were separated into three groups: negative for COVID-19 and other viruses (NEGS, n = 5); negative for COVID-19 but positive for the presence of other viruses (OTHERS, n = 5); and the positive for COVID-19 (COVID-19, n = 27). Higher specific-SIgA for SARS-CoV-2, IFN-ß, and IFN-γ were found in the COVID-19 group than in the other groups. Increased IL-12p70 levels were observed in OTHERS group as compared to COVID-19 group. When the COVID-19 group was sub stratified according to the illness severity, significant differences and correlations were found for the same parameters described above comparing severe COVID-19 to the mild COVID-19 group and other non-COVID-19 groups. For the first time, significant differences are shown in the airway's mucosa immune responses in different groups of patients with or without respiratory SARS-CoV-2 infection.

Imported hepatopulmonary echinococcosis: first report of Echinococcus granulosus sensu stricto (G1) in Bolivia.

Hepatopulmonary hydatidosis in young children is a rare and atypical presentation of Echinococcus granulosus infection. We report the first case of cystic echinococcosis caused by a microvariant of E. granulosus sensu stricto. Chemotherapy and systemic corticoids were administered before curative surgery was performed. Recurrence was not observed for more than 24 months of follow-up.

First report of two consecutive respiratory syncytial virus outbreaks by the novel genotypes ON-1 and NA-2 in a neonatal intensive care unit.

OBJECTIVE: Respiratory syncytial virus is a pathogen frequently involved in nosocomial outbreaks. Although several studies have reported nosocomial outbreaks in neonatal intensive care units, molecular epidemiology data are scarce. Here, the authors describe two consecutive respiratory syncytial virus outbreaks caused by genotypes ON-1 and NA-2 in a neonatal intensive care unit in São Paulo, Brazil. METHODS: A prospective search for respiratory syncytial virus was performed after diagnosing the index case and four other symptomatic newborns in the neonatal intensive care unit. Nasopharyngeal aspirate samples of all patients in the neonatal intensive care unit were tested for 17 respiratory viruses using real-time reverse transcriptase polymerase chain reaction. Genotyping was performed using nucleotide sequencing. RESULTS: From May to August 2013, two different outbreaks were detected in the neonatal intensive care unit. A total of 20 infants were infected with respiratory syncytial virus-A (ten and 14 with ON-1 and NA-2 genotypes, respectively). The mean age of the infants was 10 days, mean birth weight was 1,961g, and the mean gestational age was 33 weeks. Risk factors (heart disease, lung disease, and prematurity) were present in 80% and 85.7% of infants in the ON-1 and NA-2 groups, respectively. In total, 45.8% of infants were asymptomatic and 20.8% required mechanical ventilation. Coinfections were not detected during the outbreaks. CONCLUSIONS: Infants in a neonatal intensive care unit who develop abrupt respiratory symptoms should be tested for respiratory viruses, especially respiratory syncytial virus. Even in the absence of severe symptoms, respiratory syncytial virus detection can prevent nosocomial transmission through infection control measures. A better understanding of respiratory syncytial virus molecular epidemiology is essential for developing new vaccines and antiviral drugs against respiratory syncytial virus.