Does vaccination with the varicella vaccine within four weeks after the measles, mumps and rubella vaccine reduce protection?
Notice bibliographique
Résumé
Collin Yong, a paediatrician in Vancouver, British Columbia, described the present case and posed the question. A public health nurse checked the immunization history of a child in kindergarten and told the parents that the child's varicella vaccination was invalid because it was given too soon (26 days) after the measles, mumps and rubella (MMR) vaccination. They were advised to repeat the vaccination to be more certain of protection. The parents were upset to learn that their child might not be protected. The family doctor was also upset because he believed he had been exemplary in advocating for the use of a new and somewhat controversial vaccine. His question to the paediatrician was whether giving varicella vaccine within four weeks after the MMR vaccination actually reduces protection – what is the evidence for this? The Canadian Immunization Guide (1) advises that MMR and varicella vaccinations should be given at the same time or separated by at least four weeks. These alternative schedules elicit equivalent immune responses to all four antigens (2). The concern regarding a shorter separation interval first arose when reduced responsiveness to smallpox vaccination was noted in children recently given the measles vaccine (3). Fireman et al (4) showed that the administration of a live attenuated measles vaccine suppressed delayed hypersensitivity responses for one to four weeks and interfered temporarily with the in vitro response capacity of peripheral blood lymphocytes. Suppression of cell-mediated immunity after natural measles is substantial (5), providing biological plausibility for an effect after MMR vaccination. Support for an effect on varicella vaccination is limited to a retrospective cohort study (6) of breakthrough varicella infections (vaccine failures) in vaccinated American children. When varicella vaccination followed MMR vaccination by fewer than 28 days, breakthrough infection occurred three times more frequently (95% CI 1.5 to 6.4) than after greater separation of the vaccinations. Given that breakthrough infection may occur in 3% to 4% of Canadian children annually after a single dose of varicella vaccine (7), mistiming the vaccination could increase the risk of breakthrough infection to as high as 10% to 15% per year. The public health nurse was correct to recommend a remedial dose for the child described above. The potential for response interference likely diminishes toward the end of the four-week period after MMR vaccination, but public health guidelines need to be evidence-based, and evidence only exists for separation intervals of 28 days or more. The caution only applies to live virus vaccines. The recent availability of a combined MMR-varicella vaccine (Priorix-Tetra, GlaxoSmithKline, Canada) will facilitate concurrent vaccinations, avoiding the potential for mistiming sequential vaccinations. The movement toward routine use of two doses of varicella vaccine, as recently recommended in the United States (8), will also help to ensure that children are optimally protected. The Upshots column in Paediatrics & Child Health is meant to address practical questions without ready answers in standard references such as the Red Book or the Canadian Immunization Guide. Readers are invited to submit questions to the Journal office. A timely response will be provided, whenever possible, from one member of a panel of experts. The most interesting exchanges will be selected for publication. Submitters should identify themselves, but will be given the option of anonymity in the published version. Submit questions directly to journal@cps.ca. Please note that these may be edited for clarity and brevity. David Scheifele MD Associate Editor, Paediatrics & Child Health
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 0,009 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,001 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,001 | 0,002 |
| Communication savante | 0,001 | 0,002 |
| Science ouverte | 0,001 | 0,000 |
| Intégrité de la recherche | 0,010 | 0,003 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 0,001 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».