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. METHODS: We performed clinical and serological follow-up of participants in a previous study of Mexican children aged 6-7years, in which participants were randomized to four groups receiving, by aerosolized or by injection, the MMR SII vaccine (Serum Institute of India), or the MMR II (Merck Sharp & Dhome). We evaluated the antibody persistence by PRN test for measles and by ELISA for rubella and mumps. The occurrence of clinical events was evaluated via periodic visits of a nurse team to children's schools and homes. RESULTS: Of the 260 initial participants, 241 completed one-year follow-up. There were only statistically significant differences in baseline seropositivity for mumps. One year after immunization, seropositivity in all groups was 100% for measles and rubella. The seropositivity rank for mumps was from 90.3% for the injected vaccine MMR II to 96.6% for vaccine MMR SII applied by aerosol; these differences were not statistically significant. With exception of the aerosolized vaccine MMR SII for the geometric mean titer (GMT) for measles, all study groups presented declination of GMT for the three viruses. The difference between the aerosolized vaccines MMR SII and MMR RII was statistically significant for mumps antibodies. Only mild clinical events were identified. CONCLUSION: Under conditions of no endemic transmission for measles and rubella, and of low circulation of mumps virus, school-aged children remained seropositive to the three viruses one year following booster immunization. The study was registered under CMN 2010-005 number at COFEPRIS (National Regulatory Authority).

Aerosolized MMR vaccine: evaluating potential transmission of components to vaccine administrators and contacts of vaccinees.

Although numerous operative and immunological advantages accompany aerosol immunization, potential vaccine virus transmission from the aerosol device to vaccine administrators or from aerosol vaccinees to their contacts requires further study. We conducted a clinical and serological follow-up study of vaccine administrators and matched classroom or household contacts of young adults who received the MMR vaccines by aerosol or injection. Differences in incidence of clinical adverse events between vaccinees and contacts were not statistically significant. No seroresponses to any components of MMR vaccine were noted among 25 matched contacts of persons receiving injected vaccines, and only one equivocal seroresponse was noted among 25 matched contacts of aerosol recipients. No seroresponses were observed in 3 persons who administered aerosol vaccine. The composite findings of this study provide additional evidence of the safety of this approach.

A new, rapid, and promising approach to aerosol immunization: inflatable bags and valved masks.

Booster doses of MMR vaccine equal in dosage to injected doses were aerosolized into a 3/4 l bag that inflated in 4s. The bag was then attached to valved masks, and its contents rapidly inhaled in one or two deep breaths by preschool Mexican children. Antibody responses in the children exposed to the aerosolized measles component were superior to those noted after injection, while responses to the mumps and rubella components were equivalent. The new method appears to be effective, safe, and has several advantages over previously used methods. Further explorations of the approach seem merited.

Aerosol measles vaccination in macaques: preclinical studies of immune responses and safety.

The comparative efficacy and safety of measles vaccination via the aerosol route versus subcutaneous injection has not been fully resolved. We vaccinated cynomolgus monkeys (Macaca fascicularis) with the live-attenuated Edmonston-Zagreb measles virus (MV) vaccine and compared different routes of administration in the immunocompetent and the immunocompromised host. Immunogenicity and protective efficacy of aerosol vaccination using devices similar to those previously used in humans were comparable to those in animals vaccinated by injection. No evidence for a safety hazard associated with the route of vaccination was detected. The results of this study support further clinical evaluation of aerosol vaccination for measles.

Immunologic studies of specific mucosal and systemic immune responses in Mexican school children after booster aerosol or subcutaneous immunization with measles vaccine.

The purpose of the present study was to compare serum and mucosal immune responses following either aerosol (Aer) or subcutaneous (SQ) measles immunization of Mexican school children. A cohort of 49 children from 6 to 7 years of age received either Aer ( n = 22) or SQ ( n = 27) Edmonston-Zagreb (EZ) measles vaccine. Serum and nasal secretions were collected prior to (Pre), 1 and 3 months (mos) intervals and analyzed for immunoglobulin (Ig) concentrations and measles specific Ig isotype-associated antibody by enzyme immunoassay (EIA). Serum and nasal IgG and IgA antibody responses were stimulated following immunization with live, attenuated EZ measles vaccine administered either by SQ or Aer routes but these responses were significantly greater by the Aer compared to the SQ route. These studies also suggest that the level of antibody in these secretions may serve as an important marker of immunity to measles and lend further support for aerosol immunization as an effective alternative vaccine delivery strategy for measles eradication.

Aerosolized measles and measles-rubella vaccines induce better measles antibody booster responses than injected vaccines: randomized trials in Mexican schoolchildren.

OBJECTIVE: To compare antibody responses and side-effects of aerosolized and injected measles vaccines after revaccination of children enrolling in elementary schools. METHODS: Vaccines for measles (Edmonston-Zagreb) or measles-rubella (Edmonston-Zagreb with RA27/3) were given by aerosol or injection to four groups of children. An additional group received Schwarz measles vaccine by injection. These five groups received vaccines in usual standard titre doses. A sixth group received only 1000 plaque-forming units of Edmonston-Zagreb vaccine by aerosol. The groups were randomized by school. Concentrations of neutralizing antibodies were determined in blood specimens taken at baseline and four months after vaccination from randomized subgroups (n = 28-31) of children in each group. FINDINGS: After baseline antibody titres were controlled for, the frequencies of fourfold or greater increases in neutralizing antibodies did not differ significantly between the three groups that received vaccine by aerosol (range 52%-64%), but they were significantly higher than those for the three groups that received injected vaccine (range 4%-23%). Mean increases in titres and post-vaccination geometric mean titres paralleled these findings. Fewer side-effects were noted after aerosol than injection administration of vaccine. CONCLUSION: Immunogenicity of measles vaccine when administered by aerosol is superior to that when the vaccine is given by injection. This advantage persists with aerosolized doses less than or equal to one-fifth of usual injected doses. The efficacy and cost-effectiveness of measles vaccination by aerosol should be further evaluated in mass campaigns.

La vacunación antisarampionosa en México por el método de aerosol / Anti-measles vaccination by aerosol in Mexico

En este trabajo se describen las acciones de vacunación contra el sarampión por el método de aerosol inhaladado llevada a cabo en la República Mexicana entre 1988 y 1990. Se hace mención pormenorizada del equipo simplificado que se empleó, del personal, de su adiestramiento, de la promoción y de la estructura de las campañas correspondientes. También se precisa la vacuna usada: cepa Edmonston-Zagreb cultivada en células diploides, del Instituto Nacional de Virología de la Secretaría de Salud en México, con un título que varió, de 10 4.5 unidades formadoras de placa/ml (PFU/ml) a 10 4.8 PFU/ml, administrada en 30 segundos de inhalación, con un descarga del nebulizados, durante este lapso, de 2 800 a 4 000 PFU por niño, estimándose la dosis retenida en 25 por ciento , por ejemplo, 700 a 1 000 PFU. En total se tiene documentada la vacunación de 3 760 684 niños prescolares y escolares en 13 de las 32 entidades federativas del país. No se observaron efectos indeseables de gravedad y los estudios limitados que se realizaron, tanto serológicos como de campo, avalan la efectividad y seguridad de este método que es, por otra parte, mucho más barato, rápido y aceptable por la población que el de inyección subcutánea.

Vacunas anti-sarampión / Vaccines anti-measles

El sarampión es una enfermedad infecciosa causada por un virus con RNA de la familia de los paramixovirus. Aunque generalmente es benigna en la niñez, a veces se complica con infecciones secundarias y se le ha implicado como agente etiológico de la panencefalitis subaguda esclerosante, que es una expresión tardía de una infección sarampionosa latente. Debido a que este virus sólo infecta a seres humanos, su control o erradicación son situaciones que pueden hacerse posibles a través de la vacunación específica. Los subtítulos que componen este trabajo son: Cuadro clínico, Definición de caso, Complicaciones, El agente etiológico; Transmisión, epidemiología. El influjo de la vacunación; Sarampión y vacunación en México, El sarampión en los Estados Unidos, El problema continental, El sarampión en el ámbito universal, Vacunas antisarampionosas: A.Vacunas "vivas" atenuadas, B.Vacunas sobreatenuadas, C.Vacunas "muertas"; Especificaciones para las vacunas antisarampionosas de uso corriente, y Vacunas parenterales de alto título. Experiencias recientes

El impacto de la planificación familiar en algunos indicadores de bienestar social / Impact of familiy planning as an indicator of social welfare

Para cada entidad federativa se cuantificó el impacto que tiene la planificación familiar sobre el bienestar social. Considerando a la fecundidad como la variable más importante del crecimiento poblacional del país en los últimos años, y de la cual seguirá dependiendo la estructura, volumen y dinámica demográfica, se adaptó un paquete de cómputo y se elaboraron proyecciones de población al año 2010 para ilustrar, a través de indicadores sencillos, el efecto que a mediano plazo puede tener un programa de planificación exitoso o uno deficiente en términos de las necesidades futuras de salud, educación, vivienda y empleo. Finalmente se plantearon algunas estrategias programáticas y operativas para reforzar la planificación familiar en los sistemas locales de salud y en comunidades rurales

Paludismo / Malaria

El paludismo es una enfermedad existente en México desde las primeras decadas de la Conquista. Ha sido una plaga de predominio rural. Es causado por tres de las cuatro especies conocidas: plasmodium vivax, plasmodium falciparum y plasmodium malariae, mencionadas en orden de frecuencia. En 1985, un año antes del inicio de la campaña para la erradicación del paludismo aparecieron en el país alrededor de 2.5 millones de enfermos, registrando ademas 25 mil defunciones. Se ejemplifica el sistema de transmisión: individuo enfermo-mosquito transmisor-individuo sano. Los climas propicios. Los tratamientos que desde 1903 se implementaron: uso de quinina; 1936 importación de medicamentos antipalúdicos, 1939 se crea la Comisión de Saneamiento Antimalarico; uso del D.D.T.; 1956 inicia la Campaña Nacional para la Erradicación del Paludismo con el objetivo de erradicar el paludismo en un plazo de cinco años, mediante el rociado semestral de las paredes interiores de todas las casas de las áreas palúdicas con D.D.T. suspendido con agua y el tratamiento de enfermos descubiertos. Para 1961 se conocian 3,565 casos, no se logro la meta, hubo fallas de distinta índole y repuntó el mal pues en 1970 se registrarón 57,331 casos, hasta 1989 donde se dan 96,101 casos. Replanteando las prioridades: evitar defunciones, disminuir el número de casos, control epidemiológico 1 X 1000, eliminar la transmisión y lograr la erradicación