A plain language summary of the impact of vaccines against flu and chickenpox in people with multiple sclerosis treated with cladribine tablets

WHAT IS THIS SUMMARY ABOUT?

This is a summary of an article originally published in the Multiple Sclerosis Journal. Cladribine tablets (MAVENCLAD^®) are an oral (taken by mouth) medication, approved for the treatment of people with relapsing forms of multiple sclerosis (MS, with episodes of new or worsening symptoms). They are administered for a maximum of 10 days per year, over a period of 2 years. Cladribine tablets work by temporarily reducing the number of lymphocytes, which are immune cells that help to fight off infections. Because of this, people with MS (also called PwMS) may have concerns about the effect of cladribine tablets on vaccines, as these work via immune cells to build protection against infection.

WHAT HAPPENED IN THE MAGNIFY-MS STUDY?

A study called MAGNIFY-MS investigated how long it takes for cladribine tablets to begin to work in people with a type of MS called highly active relapsing MS. During the study, some participants received their usual vaccinations against flu (influenza) and against the chickenpox virus (also called varicella zoster virus) as part of their routine medical care. The MAGNIFY-MS study gave the researchers an opportunity to look at how cladribine tablets affect the way the flu and chickenpox virus vaccines work in the body.

WHAT WERE THE RESULTS?

Cladribine tablets do not affect how well the body responds to flu and chickenpox vaccines.

WHAT DO THE RESULTS MEAN?

PwMS taking cladribine tablets who are vaccinated against chickenpox, flu or both can be protected against these diseases.

Varicella vaccine dose depended effectiveness and waning among preschool children in Hong Kong

In Hong Kong, universal varicella vaccination was introduced in July 2014 with a two-dose schedule but the vaccines had been available in the private market since 1996. With data from varicella notification and surveys on immunization coverage, we used the screening method to estimate dose-specific varicella vaccine effectiveness (VE) among preschool children in Hong Kong before universal vaccination. We estimated the VE of one- and two-dose varicella vaccination against all notified varicella as 69.4% (95% confidence interval (95% CI) 69.5-71.2) and 93.4% (95% CI 91.7-94.7), respectively. We found that VE did not decrease with time since receipt. Varicella vaccine was more effective against complications (85.4% [95% CI 48.8-95.8] for one dose and 100% [95% CI -Inf to 100] for two doses) and against hospital admission (75.2% [95% CI 53.4-86.8] for one dose and 93.1% [95% CI 47.1-99.1] for two doses). Lower protection of one-dose varicella vaccine resulted in breakthrough varicella. Under universal vaccination, second-dose varicella vaccine (given as combined measles, mumps, rubella and varicella vaccine) was first scheduled for children when they reach primary one (about 6 years of age) and was recently advanced to 18 months of age. Shortening the interval between the first dose and second dose of varicella vaccination should reduce breakthrough varicella and outbreaks in preschool.

Trends in varicella and mumps vaccination rates in children under 3 years of age in a tertiary children's hospital in Japan

BACKGROUND

In Japan, the voluntary vaccination rate is not known accurately. Although two doses of the measles and rubella vaccines have been part of the universal vaccine program since 2006, the varicella vaccine was added in October 2014 while the mumps vaccine still remains voluntary. The aim of this study was to evaluate trends in the live measles, rubella, varicella and mumps vaccination rates in Japan.

METHODS

This retrospective cohort study was conducted at Tokyo Metropolitan Children's Medical Center between October 2012 and December 2016. Patients aged 1-2 years who were admitted to the Department of General Pediatrics were enrolled. The trend in the vaccination rate against measles, rubella, varicella, and mumps was examined.

RESULTS

The measles and rubella vaccination rate was 80-90%. The varicella vaccination rate in the second quarter of 2012, the third quarter of 2014, and the fourth quarter of 2016 was 34.6%, 67.1%, and 80.7%, respectively. The mumps vaccination rate in the second quarter of 2012, the third quarter of 2014, and the fourth quarter of 2016 was 27.6%, 59.5%, and 61.8%, respectively.

CONCLUSIONS

The varicella and mumps vaccination rate improved until 2014 despite the fact that they were voluntary vaccinations. After varicella vaccination was added to the universal vaccination program, the varicella vaccination rate continued to improve. The mumps vaccination, which was not included, failed to improve, suggesting that the universal vaccination program contributed to increasing the uptake of the vaccines it includes.

Vaccination campaign at a temporary camp for victims of the earthquake in Lorca (Spain)

Outbreaks in temporary camps are an important risk for the health of the displaced population. The town of Lorca (Murcia, Spain) suffered 2 earthquakes on May 2011 that required the re-housing of 1,424 victims in a temporary camp. Following 4 cases of chickenpox control measures were adopted among the displaced population. These measures included vaccination against chickenpox; due to the existence of cases of measles in adjacent regions, it was decided to offer measles, mumps and rubella (MMR) vaccination as well. The immunization campaign was performed during 2 d (3 to 4 d after the first case). The immunity status of 1,041 (73,1%) of the residents was reviewed. Being vaccinated 523 (67%) against chickenpox and MMR, 133 (17%) against only MMR and 124 (16%) against only chickenpox. We consider the action taken was a success, as only 4 additional cases of chickenpox were subsequently recorded in the campsite, being avoidable only one of them. There is a major risk of outbreaks in a disaster situation. Because of this, conducting preventive actions are indicated to avoid doing worse this critical.

Impact of a routine two-dose varicella vaccination program on varicella epidemiology

OBJECTIVE

One-dose varicella vaccination for children was introduced in the United States in 1995. In 2006, a second dose was recommended to further decrease varicella disease and outbreaks. We describe the impact of the 2-dose vaccination program on varicella incidence, severity, and outbreaks in 2 varicella active surveillance areas.

METHODS

We examined varicella incidence rates and disease characteristics in Antelope Valley (AV), CA, and West Philadelphia, PA, and varicella outbreak characteristics in AV during 1995-2010.

RESULTS

In 2010, varicella incidence was 0.3 cases per 1000 population in AV and 0.1 cases per 1000 population in West Philadelphia: 76% and 67% declines, respectively, since 2006 and 98% declines in both sites since 1995; incidence declined in all age groups during 2006-2010. From 2006-2010, 61.7% of case patients in both surveillance areas had been vaccinated with 1 dose of varicella vaccine and 7.5% with 2 doses. Most vaccinated case patients had <50 lesions with no statistically significant differences among 1- and 2-dose cases (62.8% and 70.3%, respectively). Varicella-related hospitalizations during 2006-2010 declined >40% compared with 2002-2005 and >85% compared with 1995-1998. Twelve varicella outbreaks occurred in AV during 2007-2010, compared with 47 during 2003-2006 and 236 during 1995-1998 (P < .01).

CONCLUSIONS

Varicella incidence, hospitalizations, and outbreaks in 2 active surveillance areas declined substantially during the first 5 years of the 2-dose varicella vaccination program. Declines in incidence across all ages, including infants who are not eligible for varicella vaccination, and adults, in whom vaccination levels are low, provide evidence of the benefit of high levels of immunity in the population.