[Restructuring of the COVID-19 Vaccine Safety Committee 2020-2023 in MexicoReestruturação do Comitê para Segurança das Vacinas contra a COVID-19, 2020-2023, México].

Objective: To describe the process of restructuring the National Expert Committee and its impact on the causality assessment of events supposedly attributable to vaccination or immunization (ESAVI) in the context of vaccine safety monitoring during the COVID-19 pandemic, 2020-2023.

Method: A report was prepared on the experience of creating and operating Mexico's National Expert Committee during the aforementioned period.

Results: During the 2020-2023 period, 1293 severe ESAVIs were reported after COVID-19 vaccination; after 98.

[High-quality Follow-up Measles and Rubella vaccination Campaign in Mexico, 2021Campanha de vacinação de seguimento de alta qualidade contra sarampo e rubéola no México, 2021].

Objective: To describe Mexico's experience of a high-quality follow-up vaccination campaign against measles and rubella in children aged 1 to 4 years, and actions taken to recover the coverage of other biologics during the COVID-19 health emergency.

Method: Use of a microplanning tool in the design and implementation of a follow-up campaign to protect 8 604 781 girls and boys aged 1 to 4 years and to complete other vaccination schedules, followed by the implementation of rapid vaccination monitoring.

Results: A total of 8 026 184 doses of MR vaccine were administered to children aged 1 to 4 years, with a coverage rate of 93.

[Challenges and strategies in the response to the measles outbreak during the COVID-19 Pandemic in Mexico, 25 Years after eliminationDesafios e estratégias na resposta ao surto de sarampo durante a pandemia de COVID-19 no México, 25 anos pós-eliminação].

Objective: Identify the challenges that Mexico faced during the measles outbreak during the COVID-19 pandemic and describe the interventions to interrupt measles virus circulation.

Methods: Descriptive, retrospective study of actions taken during the measles outbreak during the COVID-19 pandemic.

Results: Epidemiological surveillance of febrile exanthematous diseases has been carried out continuously in the country since 1992.

Psychological and Psychiatric Events Following Immunization with Five Different Vaccines against SARS-CoV-2.

Background: Despite the high number of vaccines administered against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) worldwide, the information on the psychological/psychiatric adverse events following immunization (AEFI) with these newly developed vaccines remains scarce.

Objective: To describe the frequency of psychological/psychiatric symptoms among recipients of five different anti-SARS-CoV-2 vaccines and to explore the factors associated with their development reported in the nationwide Mexican registry of AEFI against SARS-CoV-2.

Methods: Descriptive study of all the psychological/psychiatric symptoms, including anxiety, panic attacks, insomnia, and agitation reported to the Mexican Epidemiological Surveillance System from 21 December 2020 to 27 April 2021, among adult (≥18 years old) recipients of 7,812,845 doses of BNT162b2, ChAdOx1 nCov-19, rAd26-rAd5, Ad5-nCoV, or CoronaVac.

Anaphylaxis to SARS-CoV-2 Vaccines in the Setting of a Nationwide Passive Epidemiological Surveillance Program.

Background: Information on anaphylaxis among recipients of vaccines against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains scarce.

Objective: To identify the observed incidence of anaphylaxis in recipients of different anti-SARS-CoV-2 vaccines.

Methods: A nationwide observational study among recipients of 61,414,803 doses of seven different anti-SARS-CoV-2 vaccines, describing the incidence and characteristics of adult patients (age ≥ 18 years) who developed anaphylaxis as an adverse event following immunization (AEFI) against SARS-CoV-2 vaccines between December 24, 2020, and October 15, 2021, in Mexico.

Seizures following COVID-19 vaccination in Mexico: A nationwide observational study.

The COVID-19 pandemic led to the development and emergency approval of an array of effective vaccines against SARS-CoV-2. Given the relatively small number of patients included in vaccine trials, postapproval epidemiological surveillance is crucial to detect infrequent vaccine-related adverse events. We conducted a nationwide retrospective descriptive study evaluating the incidence of seizures among recipients of SARS-CoV-2 vaccines in Mexico from December 24, 2020 (date of administration of first doses nationwide) to October 29, 2021.

Innovation and immunization program management: traceability and quality in Latin America and the Caribbean, laying the groundwork for a regional action plan.

Introduction: The Latin American Society of Pediatric Infectious Diseases (SLIPE by its Spanish acronyms) is working to understand the current situation, gaps, and opportunities for traceability of the quality vaccination process in Latin America and the Caribbean.

Areas Covered: On September 24th and 25th, a Latin American forum of experts in immunization programs was held through the Zoom platform; the topics discussed included: computerized systems for recording immunizations, vaccination programs traceability, challenges, and information systems for the integrated management of vaccination.

Expert Opinion: Latin American countries have transitioned from having a nominal registration system to a nominal tracking system, with many of them not migrating their platforms to new technologies; therefore, the low-quality data, fragmented databases, and slow information traffic present a challenge that must be taken on.

Transient sensory symptoms among first-dose recipients of the BNT162b2 mRNA COVID-19 vaccine: A case-control study.

mRNA-based COVID-19 vaccines are effective; however, persistent vaccine hesitancy is partly due to a misperception of their potential adverse events. Non-specific sensory symptoms (NSSS) following immunization are thought to be mediated by stress-related responses. In this case-control study, we evaluated NSSS from a cohort of 7,812,845 BNT162b2 first-dose recipients, of whom 10,929 reported an adverse event following immunization (AEFI).

Neurologic adverse events among 704,003 first-dose recipients of the BNT162b2 mRNA COVID-19 vaccine in Mexico: A nationwide descriptive study.

mRNA vaccines against SARS-CoV-2 are remarkably effective. Limited information exists about the incidence of adverse events following immunization (AEFI) with their use. We conducted a prospective observational study including data from 704,003 first-doses recipients; 6536 AEFI were reported, of whom 65.

Seroprevalence of measles antibodies and factors associated with susceptibility: a national survey in Mexico using a plaque reduction neutralization test.

Measles continues to be one of the leading causes of child mortality worldwide, even though a highly effective vaccine has existed for more than 40 years. We aimed to describe the seroprevalence of measles antibodies in Mexico in 2012 and the risk factors associated with susceptibility. A total of 7,785 serum samples were analyzed from the National Health and Nutrition Survey in Mexico.

[Trends in vaccination coverage among children aged 12-23 and 24-35 months in Mexico. Ensanut 2012 and Ensanut 100].

Objective: To evaluate and compare vaccination coverage among children aged 12-23 and 24-35 months living in localities with less than 100 000 inhabitants in Encuesta Nacional de Salud y Nutrición (Ensanut) 2012 and Ensanut 100k (2018).

Materials And Methods: Estimate of coverage with both surveys.

Results: Between 2012 and 2018, according to proof and self-report, the coverage of the basic scheme was maintained in children aged 12-23 (51.

Characterization of Household and Community Shedding and Transmission of Oral Polio Vaccine in Mexican Communities With Varying Vaccination Coverage.

Background: The World Health Assembly 2012 Polio Eradication and Endgame Strategic Plan calls for the eventual cessation of all oral polio vaccines (OPVs), to be replaced with inactivated polio vaccine (IPV); however, IPV induces less robust mucosal immunity than OPV. This study characterized household and community OPV shedding and transmission after OPV vaccination within primarily IPV-vaccinated communities.

Methods: Households in 3 IPV-vaccinated Mexican communities were randomized to receive 3 levels of OPV vaccination coverage (70%, 30%, or 10%).

Protocol Paper: Oral Poliovirus Vaccine Transmissibility in Communities After Cessation of Routine Oral Poliovirus Vaccine Immunization.

Background: We aimed to elucidate household and community-level shedding and transmission of trivalent oral polio vaccine (tOPV) in communities with inactivated polio vaccine (IPV) routine immunization after tOPV is administered during a national health week (NHW).

Methods: We conducted a 3-arm, randomized trial with data collected at baseline through 10 weeks post-NHW in households with at least 1 child <5 years old in 3 semi-rural communities in Orizaba, Mexico. Selected communities were geographically isolated but socio-demographically similar.

Seroprevalence of Poliomyelitis Antibodies Among Children Aged 1 to 4 Years Old and Factors Associated With Poliovirus Susceptibility; Mexican Health and Nutrition Survey, 2012.

Background: An essential component of the "Polio Eradication and Endgame Strategic Plan 2013-2018" is the evaluation of population immunity. Mexico introduced the inactivated polio vaccine (IPV) into its routine immunization schedule in 2007 but continued to give trivalent oral polio vaccine OPV twice a year during National Health Weeks through 2016.

Methods: To describe the seroprevalence of poliomyelitis among children one to four years old in Mexico and analyze risk factors for susceptibility.

[Vaccination coverage and proportion of incomplete vaccination schedule in children under seven years of age in Mexico].

Objective: To assess vaccination coverage in children under seven years of age.

Materials And Methods: Study based on the Halfway National Health and Nutrition Survey (Ensanut MC 2016).

Results: Full vaccination coverage in children <1 year was 51.

[[Antibody prevalence to mumps in children and adolescents at two years of the introduction of the MMR vaccine]].

Objective: To assess the prevalence of mumps antibodies in children and adolescents of Mexico, two years after the introduction of the mumps-containing vaccine MMR.

Materials And Methods: Evaluation of IgG antibodies with a commercial kit of indirect ELISA.

Results: 2 111 children (1-9 years) and 2484 adolescents (10-19 years) were studied.

Antibody persistence in children aged 6-7years one year following booster immunization with two MMR vaccines applied by aerosol or by injection.

Importance: In a previous study on booster vaccination, we reported that two aerosolized MMR vaccines were as safe and immunogenic as injectable vaccines containing the same antigens. We now present results of antibody persistence one year after immunization.

Objective: To assess the antibody persistence for measles, mumps, and rubella one year following booster immunization.

Missed Opportunities for Vaccination in the Dominican Republic: Results of an Operational Investigation.

. Despite the success of the Dominican Republic's National Immunization Program, homogenous vaccine coverage has not been achieved. In October 2012, the country implemented a study on missed opportunities for vaccination (MOVs) in children aged <5 years.

[Analysis of the evidence on the efficacy and safety of CYD-TDV dengue vaccine and its potential licensing and implementation through Mexico's Universal Vaccination Program].

Dengue is a major global public health problem affecting Latin America and Mexico Prevention and control measures, focusing on epidemiological surveillance and vector control, have been partially effective and costly, thus, the development of a vaccine against dengue has created great expectations among health authorities and scientific communities worldwide. The CYD-TDV dengue vaccine produced by Sanofi-Pasteur is the only dengue vaccine evaluated in phase 3 controlled clinical trials. Notwithstanding the significant contribution to the development of a vaccine against dengue, the three phase 3 clinical studies of CYD-TDV and the meta-analysis of the long-term follow up of those studies, have provided evidence that this vaccine exhibited partial vaccine efficacy to protect against virologically confirmed dengue and lead to four considerations: a) adequate vaccine efficacy against dengue virus (DENV) infections 3 and 4, less vaccine efficacy against DENV 1 and no protection against infection by DENV 2; b) decreased vaccine efficacy in dengue seronegative individuals at the beginning of the vaccination; c) 83% and 90% protection against hospitalizations and severe forms of dengue, respectively, at 25 months follow-up; and d) increased hospitalization for dengue in the vaccinated group, in children under nine years of age at the time of vaccination, detected since the third year of follow-up.

Lessons learned from the development of a new methodology to assess missed opportunities for vaccination in Latin America and the Caribbean.

The Pan American Health Organization recently developed a practical guide for evaluating missed opportunities for vaccination among children aged <5 years. A missed opportunity occurs when an individual eligible for vaccination has contact with a health facility and does not receive a needed vaccine, despite having no contraindications. In this article, we discuss the strengths and limitations of this new methodology and present lessons learned from recent studies on undervaccination in Latin America.

Booster immune response in children 6-7 years of age, randomly assigned to four groups with two MMR vaccines applied by aerosol or by injection.

Importance: Aerosol immunization may be a useful tool to reach and sustain the elimination of measles, rubella, and congenital rubella syndrome. We compared booster seroresponses to aerosolized or injected MMR vaccines containing different strains of measles (Attenuvax or Edmonston-Zagreb) and mumps (Jeryl-Lynn or Leningrad-Zagreb).

Objective: To assess the safety and immunogenicity of two MMR: Vaccines administered by aerosol.

A systematic review of rubella vaccination strategies implemented in the Americas: impact on the incidence and seroprevalence rates of rubella and congenital rubella syndrome.

Objective: To evaluate the impact of rubella vaccination strategies on the rates of acquired rubella and congenital rubella syndrome in the Americas.

Methods: We conducted a systematic review of the literature (MEDLINE, PubMed, EMBASE, Cochrane Library, Artemisa Database, LILACS Database, Evidence Portal, VHL-PAHO Portal, Scielo, and Grey-Literature sources) that was published from 1969-2010. We included studies on rubella incidence and seroprevalence rates that were associated with rubella vaccination.