Acute Demyelinating Events Following Vaccines: A Case-Centered Analysis.

Background:  Case reports have suggested that vaccines may trigger transverse myelitis (TM) or acute disseminated encephalomyelitis (ADEM), but the evidence for a causal association is inconclusive. We analyzed the association of immunization and subsequent development of TM or ADEM.

Methods:  We identified all cases of TM and ADEM in the Vaccine Safety Datalink population.

Risk of underlying chronic medical conditions for invasive pneumococcal disease in adults.

Purpose: In the United States, the 13-valent pneumococcal conjugate vaccine is recommended in persons ⩾65years of age, and persons ⩽65years of age with immunocompromising (IC) conditions. For invasive pneumococcal disease (IPD) prevention in those ⩽65 with non-IC medical conditions, the 23-valent polysaccharide vaccine is recommended. This group is at higher risk of IPD than the general population, but the level of risk is not well-quantified.

Case-centered Analysis of Optic Neuritis After Vaccines.

We evaluated the risk of optic neuritis (ON) after vaccines, using a case-centered analysis, comparing the time since vaccination for the patients with ON with that for all similar vaccinees in a large integrated health plan population. We did not detect any association between ON and receipt of any type of vaccine.

Sudden-Onset Sensorineural Hearing Loss after Immunization: A Case-Centered Analysis.

Objective: Case reports of sudden sensorineural hearing loss (SSHL) following vaccines have led to concerns that vaccines may rarely cause hearing loss. Because of this concern, we analyzed for an association between SSHL and vaccinations.

Study Design: We used a case-centered method, equivalent to a case control design using immunization dates from all matched members of the population to calculate exposure to vaccines, rather than sampling.

Waning Tdap Effectiveness in Adolescents.

Background And Objective: Because the effectiveness of diphtheria-tetanus-acellular pertussis (DTaP) vaccine wanes substantially after the fifth dose at ages 4 to 6 years, there is a growing cohort of adolescents who rely on tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) for protection against pertussis. Yet despite high Tdap vaccine coverage among adolescents, California experienced large pertussis outbreaks in 2010 and 2014. We investigated Tdap vaccine effectiveness (VE) and waning within Kaiser Permanente Northern California among adolescents exclusively vaccinated with DTaP vaccines.

Risk of chronic arthropathy among women after rubella vaccination. Vaccine Safety Datalink Team.

Context: A review by the Institute of Medicine found a possible relationship between rubella vaccination and chronic arthritis among women.

Objective: To evaluate the risk of persistent joint and neurologic symptoms in rubella seronegative women subsequently vaccinated with RA 27/3 rubella vaccine.

Design: Retrospective cohort study based on computerized laboratory data and medical record review.

Apparent decreased risk of invasive bacterial disease after heterologous childhood immunization.

To investigate the possibility that there might be an increased risk of heterologous invasive bacterial disease after routine childhood immunization with measles, mumps, and rubella vaccine live; diphtheria and tetanus toxoids and pertussis vaccine; and oral poliovirus vaccine live, a case-control study was conducted within the Kaiser Permanente Northern California pediatric population. Contrary to the premise, an apparent protective effect against invasive bacterial disease was detected after all childhood vaccinations. However, when adjustment was made for frequency of well-care visits and day-care attendance, no significant relationship was seen between receipt of routine childhood immunizations and risk of invasive heterologous bacterial disease for any individual vaccine, although a statistically significant protective effect was detected within 1 or 3 months after the receipt of any vaccine.