Vaccine effectiveness of CanSino (Adv5-nCoV) COVID-19 vaccine among childcare workers -- Mexico, March-December 2021

BackgroundBeginning in March 2021, Mexico vaccinated childcare workers with a single-dose CanSino Biologics (Adv5-nCoV) COVID-19 vaccine. Although CanSino is currently approved for use in 10 Latin American, Asian, and European countries, little information is available about its vaccine effectiveness (VE). MethodsWe evaluated CanSino VE within a childcare worker cohort that included 1,408 childcare facilities. Participants were followed during March-December 2021 and tested through SARS-CoV-2 RT-PCR or rapid antigen test if they developed any symptom compatible with COVID-19. Vaccination status was obtained through worker registries. VE was calculated as 100% x (1-hazard ratio for SARS-CoV-2 infection in fully vaccinated vs. unvaccinated participants), using an Andersen-Gill model adjusted for age, sex, state, and local viral circulation. ResultsThe cohort included 43,925 persons who were mostly (96%) female with a median age of 32 years; 37,646 (86%) were vaccinated with CanSino. During March-December 2021, 2,250 (5%) participants had laboratory-confirmed COVID-19, of whom 25 were hospitalized and 6 died. Adjusted VE was 20% (95% CI = 10-29%) against illness, 76% (42-90%) against hospitalization, and 94% (66-99%) against death. VE against illness declined from 48% (95% CI = 33-61) after 14-60 days following full vaccination to 20% (95% CI = 9-31) after 61-120 days. ConclusionsCanSino vaccine was effective at preventing COVID-19 illness and highly effective at preventing hospitalization and death. It will be useful to further evaluate duration of protection and assess the value of booster doses to prevent COVID-19 and severe outcomes. SummaryWe evaluated CanSino (Adv5-nCoV) COVID-19 vaccine effectiveness during March-December 2021 using a childcare worker cohort that included 43,925 participants across Mexico. Vaccination decreased the risk of COVID-19 illness by 20%, hospitalization by 76%, and death by 94%.

Hacia la erradicación de la poliomielitis: logros y retos en México

Desde la implementación de las estrategias globales de erradicación, la incidencia de parálisis poliomielítica ha disminuido dramáticamente. Cuatro estrategias han contribuido notablemente: a) Altas coberturas de inmunización con vacuna oral de polio (VOP), b) Inmunización suplementaria durante los Días Nacionales de Vacunación, c) Vigilancia epidemiológica efectiva de casos de parálisis flácida aguda (PFA), y d) Bloqueos vacunales en zonas de alto riesgo. Sólo quedan tres países polioendémicos, no obstante, cualquier país corre el riesgo potencial de importación del virus de algunas de estas áreas, de la liberación accidental del virus resguardado en laboratorios de diagnóstico clínico o investigación, o de la presencia de virus circulantes derivados de vacuna en el medio ambiente. Este documento pretende exponer los antecedentes históricos que hicieron posible la eliminación de la enfermedad en México, así como los retos para lograr un mundo libre de poliomielitis.

Since the strategies to eradicate polio were implemented, the incidence of paralytic polio has dropped dramatically. Four main strategies have greatly contributed: a) High immunization coverage rate with oral polio vaccine (OPV), b) Supplementary immunization activities during the National Immunizations Days c) An effective epidemiological surveillance system for acute flaccid paralysis (AFP) and d) Intensified immunization activities in high risk areas. Three countries remain polio endemic, nevertheless, any country has a potential risk of the virus importation from one of these endemic areas; an accidental release of poliovirus from a research or clinical laboratory, or from having a circulating vaccine-derived poliovirus in the environment. The present document aims to provide an historical background that made possible the disease elimination in Mexico. Moreover, we discuss the challenges that every country needs to face in order to achieve a polio-free world.

[Booster vaccination against Bordella pertussis during pregnancy]. / Vacunación de refuerzo contra Bordetella pertussis en mujeres embarazadas.

During the last decades, the incidence of whopping cough, has been rising worldwide, despite the high coverage of the immunization programs. The highest mortality is found among children under 6 month of age, who are too young to have completed a primary vaccination series with three doses the pertussis vaccine, nevertheless this disease also affects adolescents and adults, who may only manifest mild symptomatology. Hence they do not get diagnosed or treated, becoming a potential community source of infection for young children. In order to prevent this transmission, the recommendation of vaccinating adolescents and adults, including of women in child bearing age, was issued. Nevertheless the immunization coverage among these populations was low. Postpartum vaccination was also recommended, but recent evidence have shown that the antibody levels in breast milk are detectable at least a week after immunization, allowing a window of opportunity for the infection in the newborn. Finally, it has been suggested that a booster dose against Bordetella pertussis, given to pregnant women is safe and immunogenic. Therefore, the antibody transferred across the placenta and through breast milk, could protect the product in the early stages of life.