Manisha Patel

Effectiveness of a Third Dose of MMR Vaccine for Mumps Outbreak Control

BACKGROUND The effect of a third dose of the measles–mumps–rubella (MMR) vaccine in stemming a mumps outbreak is unknown. During an outbreak among vaccinated students at the University of Iowa, health officials implemented a widespread MMR vaccine campaign. We evaluated the effectiveness of a third dose for outbreak control and assessed for waning immunity. METHODS Of 20,496 university students who were enrolled during the 2015–2016 academic year, mumps was diagnosed in 259 students. We used Fishers exact test to compare unadjusted attack rates according to dose status and years since receipt of the second MMR vaccine dose. We used multivariable time‐dependent Cox regression models to evaluate vaccine effectiveness, according to dose status (three vs. two doses and two vs. no doses) after adjustment for the number of years since the second dose. RESULTS Before the outbreak, 98.1% of the students had received at least two doses of MMR vaccine. During the outbreak, 4783 received a third dose. The attack rate was lower among the students who had received three doses than among those who had received two doses (6.7 vs. 14.5 cases per 1000 population, P<0.001). Students had more than nine times the risk of mumps if they had received the second MMR dose 13 years or more before the outbreak. At 28 days after vaccination, receipt of the third vaccine dose was associated with a 78.1% lower risk of mumps than receipt of a second dose (adjusted hazard ratio, 0.22; 95% confidence interval, 0.12 to 0.39). The vaccine effectiveness of two doses versus no doses was lower among students with more distant receipt of the second vaccine dose. CONCLUSIONS Students who had received a third dose of MMR vaccine had a lower risk of mumps than did those who had received two doses, after adjustment for the number of years since the second dose. Students who had received a second dose of MMR vaccine 13 years or more before the outbreak had an increased risk of mumps. These findings suggest that the campaign to administer a third dose of MMR vaccine improved mumps outbreak control and that waning immunity probably contributed to propagation of the outbreak. (Funded by the Centers for Disease Control and Prevention.)

Recommendation of the Advisory Committee on Immunization Practices for Use of a Third Dose of Mumps Virus–Containing Vaccine in Persons at Increased Risk for Mumps During an Outbreak

A substantial increase in the number of mumps outbreaks and outbreak-associated cases has occurred in the United States since late 2015 (1,2). To address this public health problem, the Advisory Committee on Immunization Practices (ACIP) reviewed the available evidence and determined that a third dose of measles, mumps, rubella (MMR) vaccine is safe and effective at preventing mumps. During its October 2017 meeting, ACIP recommended a third dose of a mumps virus-containing vaccine* for persons previously vaccinated with 2 doses who are identified by public health authorities as being part of a group or population at increased risk for acquiring mumps because of an outbreak. The purpose of the recommendation is to improve protection of persons in outbreak settings against mumps disease and mumps-related complications. This recommendation supplements the existing ACIP recommendations for mumps vaccination (3).

Incidence of Measles in the United States, 2001-2015

Incidence of Measles in the United States, 2001-2015 Through nationwide use of vaccination, endemic measles (ie, a transmission chain lasting 12 months or longer) was eliminated in the United States in 2000.1 Yet, importations of measles from endemic countries continue to occur, leading to outbreaks.2 We describe the incidence of measles among US residents and examine temporal trends after elimination.

Guidance for Assessment of Poliovirus Vaccination Status and Vaccination of Children Who Have Received Poliovirus Vaccine Outside the United States.

In 1988, the World Health Assembly resolved to eradicate poliomyelitis (polio). Since then, wild poliovirus (WPV) cases have declined by >99.9%, from an estimated 350,000 cases of polio each year to 74 cases in two countries in 2015 (1). This decrease was achieved primarily through the use of trivalent oral poliovirus vaccine (tOPV), which contains types 1, 2, and 3 live, attenuated polioviruses. Since 2000, the United States has exclusively used inactivated polio vaccine (IPV), which contains all three poliovirus types (2,3). In 2013, the World Health Organization (WHO) set a target of a polio-free world by 2018 (4). Of the three WPV types, type 2 was declared eradicated in September 2015. To remove the risk for infection with circulating type 2 vaccine-derived polioviruses (cVDPV), which can lead to paralysis similar to that caused by WPV, all OPV-using countries simultaneously switched in April 2016 from tOPV to bivalent OPV (bOPV), which contains only types 1 and 3 polioviruses (5). This report summarizes current Advisory Committee on Immunization Practices (ACIP) recommendations for poliovirus vaccination and provides CDC guidance, in the context of the switch from tOPV to bOPV, regarding assessment of vaccination status and vaccination of children who might have received poliovirus vaccine outside the United States, to ensure that children living in the United States (including immigrants and refugees) are protected against all three poliovirus types. This guidance is not new policy and does not change the recommendations of ACIP for poliovirus vaccination in the United States. Children living in the United States who might have received poliovirus vaccination outside the United States should meet ACIP recommendations for poliovirus vaccination, which require protection against all three poliovirus types by age-appropriate vaccination with IPV or tOPV. In the absence of vaccination records indicating receipt of these vaccines, only vaccination or revaccination in accordance with the age-appropriate U.S. IPV schedule is recommended. Serology to assess immunity for children with no or questionable documentation of poliovirus vaccination will no longer be an available option and therefore is no longer recommended, because of increasingly limited availability of antibody testing against type 2 poliovirus.

Public health responses during measles outbreaks in elimination settings: Strategies and challenges

ABSTRACT In late September 2016, the Americas became the first region in the world to have eliminated endemic transmission of measles virus. Several other countries have also verified measles elimination, and countries in all six World Health Organization regions have adopted measles elimination goals. The public health strategies used to respond to measles outbreaks in elimination settings are thus becoming relevant to more countries. This review highlights the strategies used to limit measles spread in elimination settings: (1) assembly of an outbreak control committee; (2) isolation of measles cases while infectious; (3) exclusion and quarantining of individuals without evidence of immunity; (4) vaccination of susceptible individuals; (5) use of immunoglobulin to prevent measles in exposed susceptible high-risk persons; (6) and maintaining laboratory proficiency for confirmation of measles. Deciding on the extent of containment efforts should be based on the expected benefit of reactive interventions, balanced against the logistical challenges in implementing them.

Measles Outbreak at a Privately Operated Detention Facility — Arizona, 2016

BACKGROUNDnWe describe a measles outbreak and control measures implemented at a privately operated detention facility housing US Immigration and Customs Enforcement detainees in 2016.nnnMETHODSnCase-patients reported fever and rash and were either laboratory-confirmed or had an epidemiological link to a laboratory-confirmed case-patient. Immunoglobulin G (IgG) avidity and plaque reduction neutralization tests distinguished between primary acute and reinfection case-patients. Measles-specific IgG was measured to assess detainee immunity levels. We compared attack rates (ARs) among detainees and staff, between IgG-negative and IgG-positive detainees, and by detainee housing units and sexes.nnnRESULTSnWe identified 32 measles case-patients (23 detainees, 9 staff); rash onsets were during 6 May-26 June 2016. High IgG avidity and neutralizing-antibody titers >40000 to measles (indicating reinfection) were identified in 18 (95%) and 15 (84%) of 19 tested case-patients, respectively. Among 205 unit A detainees tested for presumptive immunity, 186 (91%) had detectable IgG. Overall, the AR was 1.65%. ARs were significantly higher among detainees in unit A (7.05%) compared with units B-F (0.59%), and among male (2.33%) compared with female detainees (0.38%); however, ARs were not significantly different between detainees and staff or between IgG-negative and IgG-positive detainees. Control measures included the vaccination of 1424 of 1425 detainees and 190 of 510 staff, immunity verification for 445 staff, case-patient isolation, and quarantine of affected units.nnnCONCLUSIONSnAlthough ARs were low, measles outbreaks can occur in intense-exposure settings, despite a high population immunity, underscoring the importance of high vaccination coverage and containment in limiting measles transmission.

Notes from the Field: Absence of Asymptomatic Mumps Virus Shedding Among Vaccinated College Students During a Mumps Outbreak — Washington, February–June 2017

Absence of Asymptomatic Mumps Virus Shedding Among Vaccinated College Students During a Mumps Outbreak — Washington, February–June 2017 Jesse Bonwitt, BVSc1,2; Vance Kawakami, DVM,3; Adam Wharton, MS4; Rachel M. Burke, PhD1,4; Neil Murthy, MD1,4; Adria Lee, MSPH4; BreeAnna Dell, DVM5; Meagan Kay, DVM3; Jeff Duchin, MD3,6; Carole Hickman, PhD4; Rebecca J. McNall, PhD4; Paul A. Rota, PhD4; Manisha Patel, MD4; Scott Lindquist, MD2; Chas DeBolt, MPH2; Janell Routh, MD4

Safety of a meningococcal group B vaccine used in response to two university outbreaks

ABSTRACT Objective: To assess the safety of meningococcal group B (MenB)-4C vaccine. Participants: Undergraduates, dormitory residents, and persons with high-risk medical conditions received the MenB-4C vaccine two-dose series during mass vaccination clinics from 12/2013 through 11/2014. Methods: Adverse events (AEs) were identified by 15 minutes of observation postvaccination, spontaneous reports, surveys, and hospital surveillance. Causality was assessed for serious adverse events (SAEs). Results: 16,974 persons received 31,313 MenB-4C doses. The incidence of syncope during the 15-minutes post-dose 1 was 0.88/1000 persons. 2% of participants spontaneously reported an AE (most common were arm pain and fever). 3 SAEs were suspected of being caused by the vaccine, including one case of anaphylaxis. Conclusions: Most AEs reported were nonserious and consistent with previous clinical trial findings. Measures to prevent injury from syncope and to treat anaphylaxis should be available wherever vaccines are administered. Our safety evaluation supports the use of MenB-4C in response to outbreaks.