Burden of Disease Due to Respiratory Syncytial Virus in Adults in Five Middle-Income Countries.

Respiratory syncytial virus (RSV) is an important cause of severe respiratory disease in older adults. Understanding the disease burden is crucial for guiding vaccination policy and raising disease awareness. We estimated the burden of RSV hospitalizations and deaths in adults in five middle-income countries: Argentina, Brazil, Chile, Mexico, and Malaysia. Hospital discharge and death statistics due to any respiratory disease (ICD-10 codes: J00-99) from 2010 to 2022 were obtained. The RSV attributable burden on hospitalizations and deaths by age group was determined for 2019 using previously published estimates. Latin American countries showed distinct annual peaks in respiratory-related hospitalizations and deaths during winter months that were absent in Malaysia. Among ≥20-year-olds in 2019, there were 14,604 RSV-attributable hospitalizations nationally in Argentina, 44,323 in Brazil, 4529 in Chile, 7416 in Malaysia, and 8651 in Mexico, and 60-74% in ≥65-year-olds. There were also 3518 RSV-attributable deaths in Argentina, 9115 in Brazil, 801 in Chile, 704 in Malaysia, and 3806 in Mexico 79-88% in ≥65-year-olds. Incidences of RSV-attributable hospitalizations in ≥75-year-olds ranged between 256.3 and 294.3 per 100,000 population, and deaths between 33.6 and 112.9 per 100,000 population. RSV is associated with a substantial disease burden beyond pediatric age groups, and preventive vaccines could have a major impact on this burden, especially in older adults.

Epidemiology of Invasive Meningococcal Disease in Colombia: A Retrospective Surveillance Database Analysis.

INTRODUCTION: Invasive meningococcal disease (IMD), caused by Neisseria meningitidis, is associated with high morbidity and mortality. The aim of the current study was to describe the historical and recent epidemiology of IMD in Colombia. METHODS: This retrospective surveillance database analysis examined all available data on IMD in Colombia. Data were extracted from publicly available disease event reports and laboratory surveillance reports or obtained directly from hospitals in Cartagena. RESULTS: During 2015-2021, the overall incidence of IMD was 0.04-0.18 per 100,000 based on laboratory surveillance reports. IMD incidence was highest among infants aged < 1 year (0.52-1.47 per 100,000), as was IMD mortality (0.00-0.65 per 100,000). Serogroup B was the dominant serogroup responsible for IMD in Colombia during 1988-2014, but, since 2015, serogroup C has been dominant in all age groups, followed by serogroups B and Y. During 2010-2021 combined, the majority of IMD cases were reported in Bogotá (31.9%) and Antioquia (21.7%). Of 42 IMD cases in the city of Cartagena, 54.8% occurred in people who lived in the poorest neighborhoods, and these patients had the highest IMD lethality (52.2%) and the shortest median hospitalization duration (3 days). CONCLUSION: The overall incidence of IMD in Colombia was low but was highest among infants aged < 1 year. IMD cases tended to be concentrated in the more densely populated areas and in poorer neighborhoods. As the majority of IMD cases in Colombia since 2015 have been serogroup C, followed by B or Y, vaccination to protect against these serogroups could potentially be beneficial and help to achieve the World Health Organization's and Pan American Health Organization's roadmaps to defeat meningitis by 2030.

Cost-effectiveness analysis measuring the total costs against the health benefits of three different rotavirus vaccines for Mexico.

Rotavirus (RV) infection causes acute rotavirus gastroenteritis (RVGE) in infants. Safe and effective RV vaccines are available, of which Mexico has included one in its national immunization program (NIP) since 2007. Health outcome gains, expressed in quality-adjusted life years (QALYs), and cost improvements are important additional factors for the selection of a NIP vaccine. These two factors were analyzed here for Mexico over one year implementing three RV vaccines: 2-dose Rotarix (HRV), versus 3-dose RotaTeq (HBRV), and 3-dose Rotasiil (BRV-PV), presented in a 1-dose or 2-dose vial). HRV would annually result in discounted QALY gains of 263 extra years compared with the other vaccines by averting an extra 24,022 homecare cases, 10,779 medical visits, 392 hospitalizations, and 12 deaths. From a payer's perspective and compared with HRV, BRV-PV 2-dose vial and BRV-PV 1-dose vial would annually result in $13,548,179 and $4,633,957 net savings, respectively, while HBRV would result in $3,403,309 extra costs. The societal perspective may also show savings compared with HRV for BRV-PV 2-dose vial of $4,875,860, while BRV-PV 1-dose vial and HBRV may show extra costs of $4,038,363 and $12,075,629 respectively. HRV and HBRV were both approved in Mexico, with HRV requiring less investment than HBRV with higher QALY gains and cost savings. The HRV vaccine produced those higher health gains due to its earlier protection and greater coverage achieved after its schedule completion with two doses only, providing full protection at four months of age instead of longer periods for the other vaccines.

Rotavirus (RV) infection causes acute diarrhea in infants and can be life-threatening. Several safe and effective vaccines against RV and its complications exist. For many governments choosing vaccines for national immunization programs, total costs or savings and health gains are important factors in the selection process. We compared the costs and health benefits of three RV vaccines for Mexico: HRV, HBRV, and BRV-PV, that have different dosing schedules: two doses for HRV and three doses for HBRV and BRV-PV. HRV is currently part of the national immunization program in Mexico. HRV would result in more health benefits as it incurs fewer RV-related cases, medical visits, hospitalizations, and infant deaths than the other vaccines due to its early protection achieved after only two doses to complete its schedule. However, from a payer's perspective, the least expensive vaccine was BRV-PV, while HRV was less expensive than HBRV. From a societal perspective, also accounting for families' costs and loss in income due to an infant's RV disease, and the families' costs and loss in income when accompanying the infant to the vaccination center, the HRV vaccine was less expensive than HBRV and BRV-PV presented in a 1-dose vial, while more expensive than BRV-PV presented in a 2-dose vial. HRV and HBRV are both approved in Mexico, although HBRV requires a greater investment at lower health benefits than HRV, from both a payer's and a societal perspective. A 2-dose vaccination scheme is an important asset for the economic value of this vaccination program.

Knowledge, Attitudes, and Practices Concerning Maternal Immunization Among Pregnant/Postpartum Women and Health Care Professionals in Peru.

INTRODUCTION: For pregnant women, vaccination with inactivated influenza vaccine (IIV) and tetanus, diphtheria, acellular pertussis vaccine (Tdap) is recommended. In Peru, uptake is nonetheless low. A study was conducted to identify factors affecting maternal vaccination coverage. The study's primary objectives were to describe the knowledge, attitudes, and practices regarding maternal immunization among pregnant/postpartum women and health care professionals (HCPs). The secondary objective was to determine the vaccination coverage and the impact of Ministry of Health (MOH) recommendations. METHODS: An observational multicenter, cross-sectional survey study was conducted from February 1, 2021 to June 30, 2021 in five cities in Peru. Two surveys were conducted to assess knowledge, attitudes, and practices concerning maternal immunization: one among pregnant/postpartum women and one among HCPs. RESULTS: Participants were 668 pregnant/postpartum women with a mean age of 29.6 years and 219 HCPs-mostly midwives (46.6%) and obstetricians/gynecologists (44.7%). Of the pregnant/postpartum women, 66.9% knew that, in general, vaccinations are given for prevention, and 98.5% believed vaccines are important. Nonetheless, 69.6% of pregnant/postpartum women had poor or moderate knowledge of maternal vaccination. Disease knowledge of influenza (89.1%) and tetanus (87.0%) was high, while knowledge of pertussis (37.7%) was low. Women agreed/strongly agreed that they would get vaccinated with Tdap if a doctor (96.3%), midwife (88.9%), or nurse (72.0%) recommended it. Of the HCPs, 81.3% routinely recommended Tdap vaccination for pregnant women. CONCLUSIONS: To enhance vaccine acceptance in pregnant women in Peru, we must improve knowledge of the diseases, MOH recommendations, and benefits of the offered vaccinations. HCPs could provide this vaccination knowledge and information along with their vaccination recommendation as the pregnant/postpartum women indicated they would take the vaccines if recommended by their HCPs. Our findings are important for the successful implementation of maternal immunization programs in Peru.

Epidemiology of Herpes Zoster in Adults in Mexico: A Retrospective Database Analysis.

INTRODUCTION: The risk of herpes zoster (HZ) increases with age. In countries with an ageing population such as Mexico, a rise in the risk of HZ and complications is expected. The goal of this study was to provide an updated estimate of the potential burden of HZ and associated complications in Mexico. METHODS: A retrospective database study was performed using data from the national surveillance database of the Ministry of Health (Secretaría de Salubridad y Asistencia/Dirección General de Información en Salud). HZ cases and associated complications were identified via the International Classification of Diseases 10th Revision codes. Emergency room (ER) visits, hospitalizations, and deaths were extracted and analyzed by age group and year. The observation period was between 2011 and 2020 for ER visits and hospitalizations and between 2011 and 2019 for deaths. Cumulative incidence per 1000 people and case fatality rate were estimated. RESULTS: During the observation period, 53,030 ER visits, 4172 hospitalizations, and 263 deaths due to HZ were reported nationwide. The cumulative incidence of HZ based on ER visits was 1.04 per 1000 people aged ≥ 50 years but increased in older age groups (1.47 per 1000 people aged ≥ 65 years). The most common complications were neuralgia (10.9%), ocular disease (7.0%), meningoencephalitis (2.9%), and disseminated disease (3.1%). Patients ≥ 65 years accounted for 37% of hospitalizations and 81% of deaths. CONCLUSION: In Mexico, HZ and its complications impose a considerable burden on the population and the healthcare system. Prospective surveillance studies are required to obtain an accurate picture of the current epidemiology of HZ in Mexico and to estimate the benefits of future vaccination strategies against HZ.

Herpes zoster (HZ), also called shingles, is a disease typically characterized by a painful skin rash. It affects mostly older adults and immunocompromised populations. Approximately 30% of patients have complications such as prolonged, severe pain; eye disease; or disease affecting parts of the body other than the skin. In this study, we analyzed national passive surveillance data for HZ disease and related complications in Mexico. Over the last 10 years (2011­2020), more than 50,000 cases and 4000 hospitalizations have been observed. In those, 263 people died, and most of the deaths (81%) occurred in people aged 65 years or older. Since the proportion of older people in the Mexican population will increase over the next decades, herpes zoster will probably become more frequent and complicated. Vaccination against HZ could help protect the older population against this serious disease.

Adult immunization practices, challenges and opportunities in Central America and the Caribbean: Advisory board proceedings.

As individuals age, they become increasingly prone to infectious diseases, many of which are vaccine-preventable diseases (VPDs). Adult immunization has become a public health priority in the modern era, yet VPDs vaccination rates for adults are low worldwide. In Central America and Caribbean, national recommendations and vaccination practices in adults differ across countries, and adult vaccination coverage data are limited. An advisory board comprised infectious disease experts, pulmonologists, geriatricians, occupational health, and public health professionals for Central America and Dominican Republic was convened to: a) describe adult immunization practices in these countries; b) discuss challenges and barriers to adult vaccination; and c) find strategies to increase awareness about VPDs. The advisory board discussions reflect that national immunization guidelines typically do not include routine vaccine recommendations for all adults, but rather focus on those with risk factors. This is the case for influenza, pneumococcal, and hepatitis B immunizations. Overall, knowledge lacks about the VPD burden among health-care professionals and the general public. Even more, there is insufficient information on vaccinology for students in medical schools. Actions from the responsible authorities - medical schools and scientific societies which can advocate for vaccination and a better knowledge in vaccinology - can help address these issues. A preventive medicine culture in the workplace may contribute to the advancement of public opinion on vaccination. Promoting vaccine education and research could be facilitated via working groups formed by disease experts, public and private sectors, and supranational authorities, in an ethical and transparent manner.

Economic burden of meningococcal disease in children and adolescents in Tijuana, Mexico.

Invasive meningococcal disease (IMD) is an uncommon but serious and potentially fatal condition mainly affecting children and adolescents. Active surveillance between 2005 and 2016 at Tijuana General Hospital, Mexico, indicated that the incidence of IMD in Tijuana was higher than previously thought, at 2.69 per 100,000 population aged <16 years. The objective of this study was to estimate the economic burden associated with 51 IMD cases in children aged <16 years identified over the 11 years of active surveillance at Tijuana General Hospital, Mexico. Healthcare resource usage for the IMD cases was obtained from the hospital database and combined with unit costs from the hospital purchasing department or national databases to estimate total healthcare costs over a follow-up period of 3 months. Societal costs were represented by the value of lost wages for parents or guardians. All costs were expressed in US$. Over the 11-year study period there were 51 IMD cases, of which 13 (25%) were fatal. The total cost for all 51 cases over the 11-year study period was US$1,054,499 (average per case US$20,676), of which direct healthcare costs comprised US$1,029,948 (average per case US$20,195) and societal costs US$24,551 (average per case US$481). Extrapolated to the population of Tijuana region aged <16 years, the estimated annual economic burden of IMD was US$268,794. The major cost driver was the cost of hospitalization. These data illustrate the significant economic burden associated with IMD in Tijuana, and will be useful in assessing optimal vaccination programs against meningococcal disease in Mexico.

Burden of disease and associated complications of hepatitis a in children and adults in Mexico: A retrospective database study.

BACKGROUND: Hepatitis A virus (HAV) infection is a leading cause of viral hepatitis in children, yet the HAV vaccine is not included in the national immunization program (NIP) in Mexico. This study addresses an identified evidence gap of the burden of hepatitis A disease, complications, and associated costs in Mexico by analyzing surveillance and healthcare data. Data review included disease morbidity (incidence and hospitalization), mortality, and healthcare resource utilization costs. METHODS: In this observational, retrospective database study, we conducted a systematic screening, extraction, and analysis of outcome data from the national surveillance system in Mexico from January 2000 to December 2019. RESULTS: During the analysis period (2000-2019), the average incidence rate/year of HAV cases was 14.7 (5.4-21.5) per 100,000 inhabitants. Children 1-9 years of age (YoA) had the highest average incidence rate/year with 47.8 (14.7-74.5). The average hospitalization rate/year due to HAV infection was 5.8% (2.9-9.6%). Although the highest burden of HAV continued to be in children (1-9 YoA), an increase in incidence and hospitalizations (with complications) in older age groups (≥ 10-64 YoA) was observed. The annual average fatality rate was estimated to be 0.44% (0.26-0.83%) of which 28.8% of deaths were concentrated in adults ≥ 65 YoA. The total direct costs of medical attention due to HAV and related complications were estimated at $382 million Mexican pesos. CONCLUSION: The overall results suggest an uptrend in HAV infections in adolescents/adults compared to children in Mexico. Therefore, as the overall incidence risk of HAV infection decreases, the mean age of infection increases. This consequently increases the risk of severity and complications in older age groups, thus increasing the demand for healthcare resources. Our findings provide evidence for including the inactivated HAV vaccine in the Mexican NIP.

Impact after 10-year use of pneumococcal conjugate vaccine in the Brazilian national immunization program: an updated systematic literature review from 2015 to 2020.

In 2010, a 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) was introduced in the Brazilian national immunization program; the 3 + 1 dose schedule was replaced by a 2 + 1 dose schedule in 2016. This systematic review presents the latest published evidence (2015-2020) on the impact after 10-year use of PHiD-CV in Brazil from a total of 29 publications. Overall, the PHiD-CV program had a positive impact on the morbidity and mortality associated with invasive pneumococcal disease (IPD), pneumonia and acute otitis media (AOM) in children <5 years-old. A reduction in the vaccine-type invasive disease was observed in all-ages; suggesting indirect protection unvaccinated older children and adults. The occurrence of non-vaccine type disease was evidenced in some studies. Higher vaccination coverage is required at national and state level for sustained population impact. Given the change in the vaccination schedule and the dynamics of pneumococcal disease epidemiology, continuous surveillance is warranted.GSK Study identifier: HO-18-19438.

Laboratory-based surveillance in Latin America: attributes and limitations in evaluation of pneumococcal vaccine impact.

Disease surveillance data are needed to monitor trends in disease activity, inform decision-making in public health and evaluate disease prevention/control measures. The Sistema Regional de Vacunas (SIREVA) supports laboratory-based surveillance of invasive pneumococcal disease (IPD) in Latin American countries, providing information on identification, distribution, and anti-microbial susceptibility of pneumococcal strains. We estimated the proportion of pneumococcal meningitis and sepsis/bacteremia cases captured by SIREVA, by comparing the number of SIREVA-reported isolates in Argentina, Brazil, Chile, Colombia, Ecuador and Mexico with the estimated expected number of cases based on regional estimates of disease incidence. In all six countries, the number of isolates reported by SIREVA was consistently lower than the number of cases expected, across all years with data available. The proportion of SIREVA-reported isolates was highest in Chile (43-83%) and lowest in Mexico (1.4-3.5%). Passive surveillance systems such as SIREVA are important tools for monitoring circulating strains that could be related to pneumococcal disease, but our results show that SIREVA is likely to underestimate pneumococcal disease incidence. This under-reporting will limit the precision of surveillance data in monitoring changes in the incidence of IPD after vaccine introduction, and this should be considered when assessing the impact of vaccination programs.

PLAIN LANGUAGE SUMMARYWhat is the context?Infectious disease surveillance is an important epidemiological tool to monitor the health of a population.Surveillence can be used to detect trends in disease activity and to trigger disease control measures.In Latin America, the SIREVA surveillance system monitors occurrence of bacterial pneumonia, sepsis/bacteremia and meningitis.However, passive surveillence systems may understimate disease occurrence.What is new?We compared the number of isolates of invasive pneumococcal disease (IPD), specifically meningitis and sepsis/bacteremia, in children aged <5 years reported in SIREVA data in six countries in Latin America with the expected number of cases based on regional estimates of IPD incidence.Our results show that the number of isolates reported by SIREVA was consistently lower than the estimated number of cases, across all six countries and all the years available.The percent difference between SIREVA-reported isolates and estimated number of cases was variable between countries, ranging from 43-83% in chile to 1.4-3.5% in Mexico.What is the impact?Passive surveillance systems such as SIREVA are important tools for monitoring disease incidence, but they are likely to underestimate pneumococcal disease occrruence.This under-reporting will limit the precision of surveillance data in monitoring changes in disease incidence after vaccine introduction, and this needs to be considered when assessing vaccine impact.

Incidence and Mortality Trends of Acute Gastroenteritis and Pneumococcal Disease in Children Following Universal Rotavirus and Pneumococcal Conjugate Vaccination in Ecuador.

INTRODUCTION: Ecuador introduced routine infant rotavirus (RV) vaccination in 2008 and pneumococcal conjugate vaccination (PCV) in 2011 to manage disease and mortality in children caused by gastroenteritis (GE) and by pneumonia (PNE) and invasive pneumococcal disease (IPD), respectively. METHODS: This retrospective ecological database study described vaccination coverage as well as the trends in incidence and mortality in the pre- versus post-vaccination periods and used time-trend analysis models to assess the impact of vaccination. RESULTS: RV vaccination coverage of the second dose was between 79-97% from 2008 to 2016. GE incidence and mortality showed a declining trend before vaccination which continued in the post-vaccination period. The model estimated a statistically significant decrease of 72.4% for GE mortality and 51.2% for GE incidence in the post-vaccination period. PCV vaccination coverage remained above 80% (second dose) and 40% (third dose) after 2011. PNE mortality showed a declining trend before vaccination and a continued decline after vaccination, while PNE incidence was more variable (sharp increase from 2005-2009 then decrease and eventual stabilisation). The model estimated a statistically significant decline of 41.1% for PNE mortality and a stable PNE incidence in the post- versus pre-vaccination period. IPD incidence and mortality yearly data showed large variability by year and low numbers, making it difficult to discern a trend. The model estimated a statistically significant reduction of 51.1% for IPD mortality and 31.5% for IPD incidence in the post- versus pre-vaccination period. CONCLUSION: After the first 9 years of routine RV vaccination and 6 years of routine PCV vaccination in Ecuador, significant decreases in incidence and mortality in children < 5 years of age due to GE and pneumococcal disease have been observed.

Acute Gastroenteritis Morbidity and Mortality Trends Following Universal Rotavirus Vaccination in Children in Peru: Ecological Database Study with Time-Trend Analysis.

INTRODUCTION: Rotavirus (RV) infection is the leading cause of severe diarrhea in children worldwide. It is responsible for around 25% of gastroenteritis (GE) cases, 33% of hospitalized GE cases, and an annual mortality rate of 113.4/100,000 in children < 5 years of age in Peru. RV infant vaccination is recommended by the World Health Organization and provides the best public health strategy to manage the disease. Universal RV vaccination was introduced in Peru in 2009. METHODS: Trends in GE ambulatory visits, hospitalizations, and deaths in children < 5 years of age are described in the pre-vaccination (2004-2008) versus post-vaccination (2010-2018) periods. Time-trend analysis was performed (using generalized linear regression models) to assess the impact of vaccination nationwide and by region after adjusting for variables. RESULTS: Between 2009 and 2011, vaccination coverage increased to over 80% in Peru. In infants < 1 year of age, GE ambulatory cases, hospitalizations, and deaths decreased in the post-vaccination period by 40.3%, 46.2%, and 55.5%, respectively (and in children < 5 years of age, by 34.4%, 41.9%, and 54.3%, respectively) compared with the pre-vaccination period. Results of the multivariate time-trend analysis also found significant decreases in the post-vaccination period of 10.7% (GE ambulatory cases), 17.2% (GE hospitalizations), and 37.3% (GE mortality) in children < 5 years of age. Data analyzed by region varied, with Costa and Sierra regions generally in line with the national findings; however, some findings were less robust for Selva due to fewer available data. CONCLUSION: After 9 years of RV vaccination in Peru, there appears to be a statistically significant positive impact of vaccination, in terms of reducing GE-related mortality, hospitalizations, and ambulatory visits in infants and young children. For policymakers to understand regional differences and future vaccination needs, continued improvement in surveillance is needed.

15-year experience with rotavirus vaccination in Mexico: a systematic literature review.

A systematic review was conducted in Mexico to consolidate and evaluate evidence after 15 years of rotavirus vaccination, according to the National Immunization Program. Five databases were screened to identify published articles (January 2000-February 2020) with evidence on all clinical and epidemiological endpoints (e.g. immunogenicity, safety, efficacy, impact/effectiveness) of rotavirus vaccination in Mexico. Twenty-two articles were identified (observational studies including health-economic models: 17; randomized controlled trials: 5). Fourteen studies evaluated a human attenuated vaccine (HRV), four studies evaluated both vaccines, and only two evaluated a bovine-human reassortant vaccine, with local efficacy data only for HRV. Local evidence shows vaccines are safe, immunogenic, efficacious, and provide an acceptable risk-benefit profile. The benefits of both vaccines in alleviating the burden of all-cause diarrhea mortality and morbidity are documented in several local post-licensure studies. Findings signify overall benefits of rotavirus vaccination and support the continued use of rotavirus vaccine in Mexico.

Pertussis infant morbidity and mortality trends after universal maternal immunisation in Mexico: An ecological database study with time-series analysis.

INTRODUCTION: Pertussis is a highly contagious infectious disease caused by Bordetella pertussis and a leading cause of infant mortality in Mexico. The Tetanus-diphtheria-acellular pertussis (Tdap) vaccine was recommended in the Mexican Immunisation Programme for pregnant women in 2013. We describe pertussis morbidity and mortality trends in infants ≤2 and ≤12 months of age), before and after maternal Tdap immunisation implementation in Mexico. METHODS: An ecological retrospective database study was performed in the Mexican National and Workers Social Security Institutes (IMSS; ISSSTE). Data were collected on confirmed pertussis ambulatory cases, hospitalisations, and deaths, plus vaccination coverage (Tdap; Diphtheria-tetanus-acellular pertussis [DTPa]) and population estimates. Descriptive and regression time-trend analyses were performed for pertussis morbidity and mortality in infants between pre- (2010-2012) and post- (2014-2018) maternal Tdap immunisation periods. RESULTS: Around 1 million infants a year are covered in IMSS/ISSSTE databases. Average full primary infant DTPa vaccine coverage was 71.4%-72.7% nationally. Since 2013, annual maternal Tdap vaccine coverage ranged from 70%-93%. Between 2010-2018, 2,024 pertussis cases, 2,518 hospitalisations and 71 deaths were reported in infants. Among infants 0-2 months old (maternal immunisation target group), there was a significant decrease, post-maternal vaccination, in pertussis incidence (49.9%, p < 0.000), hospitalisation (70.0%, p < 0.000) and mortality (82.4%, p = 0.003). In infants 0-12 months old, pertussis hospitalisations (28.9%, p = 0.000) and mortality (36.2%, p = 0.059) decreased, but incidence increased (61.8%, p = 0.000). CONCLUSION: After maternal immunisation was implemented, there was a decreasing trend in incidence, hospitalisation and death due to pertussis in infants 0-2 months old. Increases in incidence reported in 0-12-month-olds are likely due to major changes in diagnosis and reporting introduced during the study period as well as limited vaccination and health coverage in some states. These findings confirm the important contribution of the Tdap maternal immunisation programme in reducing pertussis disease burden, particularly severe disease, among infants in Mexico.

Highlights of an Expert Advisory Board on Acute Exacerbations of Chronic Obstructive Pulmonary Disease (AE-COPD) in Latin America.

Background: Chronic obstructive pulmonary disease (COPD) is a preventable and usually progressive lung disease that affects millions of people worldwide and is the sixth leading cause of death in the Americas. Viral and bacterial respiratory tract infections and air pollution may cause acute exacerbations of COPD (AE-COPD) ranging from mild, moderate to severe. The greatest proportion of the overall COPD burden on the health system is due to disease exacerbations. There is limited evidence regarding the etiology and burden of AE-COPD in Latin America (LATAM). Methods: To respond to this gap in evidence, an Advisory Board with regional pneumologists and infectious disease experts was convened in September 2018 in Panama City, Panama, to: 1) review the burden of AE-COPD in LATAM; 2) evaluate the etiology of AE-COPD in LATAM; and 3) assess and compare the local/regional guidelines to confirm the etiology, characterize, and manage AE-COPD. Results: The results of the meeting showed that there is a high prevalence of AE-COPD in LATAM countries, limited evidence on etiology data, and discrepancies in the case definitions and symptomology (ie, severity) classifications used in LATAM. Conclusion: The Advisory Board discussions further resulted in recommendations for future research on the impact on the epidemiology and burden of disease, on establishing standardized AE-COPD case definition guidelines, and on studying the etiology of both moderate and severe AE-COPD cases.

Interchangeability between pneumococcal conjugate vaccines for pediatric use: a systematic literature review.

Introduction: Evidence on the interchangeability between the two pediatric pneumococcal conjugate vaccines (PCVs) - pneumococcal non-typeable Haemophilus influenzae protein D-conjugate vaccine (PHiD-CV) and 13-valent PCV (PCV13) - is limited but growing. We performed a systematic literature review to summarize evidence for PHiD-CV/PCV13 interchangeability regarding immunogenicity, safety, and effectiveness against pneumococcal disease. Areas covered: Seven records disclosing results from six studies on PHiD-CV/PCV13 interchangeability were identified. Four clinical trials showed that mixed schedules with a PHiD-CV-to-PCV13 switch at boosting or a PCV13-to-PHiD-CV switch during priming or at boosting were immunogenic with no apparent safety concerns. Two observational studies in the context of a programmatic PHiD-CV-to-PCV13 switch showed similarly high effectiveness against overall invasive pneumococcal disease with a mixed PHiD-CV/PCV13 schedule and a PCV13-only schedule. No effectiveness data for a PCV13-to-PHiD-CV switch and no immunogenicity/safety/effectiveness data for a PHiD-CV-to-PCV13 switch during priming were found. Expert opinion: For epidemiological or programmatic reasons, several local/national authorities have switched PCVs in their immunization programs. Consequently, children have received mixed schedules. Although herd immunity may obscure the individual effect, the limited data are reassuring. Additional evidence from these settings - especially effectiveness or impact data - may provide the necessary information for authorities to make informed decisions on interchanging PCVs.

Response to article by Matthew Wasserman et al. (2018): "Modeling the sustained use of the 13-valent pneumococcal conjugate vaccine compared to switching to the 10-valent vaccine in Mexico".

In a recent article, Wasserman et al. estimated and forecasted the health and economic impact of switching from the 13-valent (PCV-13) to the 10-valent (PHiD-CV) pneumococcal conjugate vaccine in Mexico's national immunization program. In this response letter, we highlight various methodological inconsistencies and model input considerations that potentially bias the results and further recommendations made by the authors.