Proceedings of the SAGE Working Group on Rubella Vaccines

Susan E. Reef, MDGlobal Measles and Rubella Management

MeetingMarch 15, 2011

Outline• Background• Terms of Reference• Opportunities to align with measles strategies• Recommendations from the WG

– Phases of rubella control and CRS prevention (Goals)– Strategies

• Paradoxical Effect • Minimum Coverage for Rubella Vaccine introduction• Recommendation from the WG on minimum threshold• Summary

Background

• Current WHO rubella vaccine position paper was published in 2000– Since the publication, there have been several

areas that have changed• Additional countries using vaccine, • 2 regions with elimination goals and one with

accelerated rubella control and CRS prevention• Additional information on vaccine safety (e.g., pregnant

women)• Additional information duration of immunity• Additional formulations of vaccine

Terms of ReferenceSAGE Working Group on Rubella

• Review and propose necessary updates to the WHO rubella vaccine position paper of 2000.

• Identify the information gaps, guide the work required to address the information gaps, and prepare for a SAGE review of the updated vaccination strategies.

• The specific questions to be addressed:– What are the possible goals for rubella/CRS prevention and rubella/CRS

elimination (country, regional or global)? – With the goals mentioned in question 1, what are the most appropriate

vaccination strategies to achieve these goals?– What is the minimum required routine immunization coverage that should

be achieved and maintained to ensure that the introduction of rubella-containing vaccine does not increase the risk of CRS?

Opportunities• In 2000 PP

– Countries undertaking measles elimination should consider taking the opportunity to eliminate rubella as well, through use of MR or MMR vaccine in their childhood immunization programmes, and also in measles campaigns

• Several potential areas of integration of measles and rubella– Combined vaccine (MR, MMR, MMRV)– Combined surveillance

• Measles/rubella surveillance• Vaccine coverage monitoring• Adverse events monitoring

TABLE of the phases

Mass vaccination campaigns with MR vaccine targeting children plus control strategies

Mass vaccination campaigns targeting all adults : men and women – plus accelerated control strategies

CONTROL ACCELERATED CONTROL ELIMINATION

Introduce rubella-containing vaccine into EPI schedule, follow-up campaigns plus adolescent/adult females

Phases of Rubella Control and CRS Prevention

CRS Prevention Only

Target adolescent girls and/or women of childbearing age for immunization either through routine services or mass campaigns

No goal

CRS Prevention Only

No rubella vaccine use

Strategies

• For each phase of rubella control and CRS prevention– Vaccination strategies– Surveillance recommendations

• Integrated measles/rubella surveillance• CRS surveillance• Monitoring vaccine coverage

StrategiesGoal Vaccination Strategy Surveillance Strategy

No introduction Not applicable Detection of rubella cases through measles case-based surveillance

During outbreakso Investigation of all rash

illness (suspected rubella) in pregnant women including laboratory testing

o Conduct laboratory testing of at least first 5-10 rash illnesses per month to confirm rubella as cause of outbreaks

o Investigate outbreakso Conduct active CRS

surveillance Collection of specimens for

molecular epidemiology (may want to include earlier)

Sentinel case-based CRS surveillance in infants 0-11 months

Strategies, con’tGoals Vaccination Strategy Surveillance Strategie

CRS prevention only • Target adolescent girls and/or women of childbearing age for immunization either through routine services or mass campaigns

Including strategies above and Rubella vaccination coverage

monitoring

Rubella control and CRS Prevention

• Including strategy above and • Introduction of RCV into the

routine childhood program –preferable to be introduced combined with both MCV1 and MCV2.

• “Follow-up” MR or MMR campaigns targeting preschool-aged children (aged 1 to 4 years)

Including strategies above and Detection of rubella cases

through measles case-based surveillance –transition to integrated measles-rubella case-based surveillance

Enhance investigation of outbreaks with laboratory testing of suspected cases

Accelerated Rubella Control and CRS Prevention

• Including strategies above and• “Catch-up” MR or MMR

campaigns targeting children aged less than 15 years.

• Including strategies above and• Enhancing integrated measles-

rubella case-based surveillance – start to investigate every suspected case

Rubella/CRS Elimination • Including strategies above and • “Speed-up” campaigns

targeting adolescents and adults, men and women.

• Including strategies above and◦ Strengthening integrated

measles-rubella or febrile rash illness surveillance – testing and investigating all suspected cases

◦ Seroprevalence studies in WCBA?, as appropriate

Paradoxical Effect• Possibility that introduction of universal childhood

vaccination with inadequate coverage may lead to an increase in CRS

• Low coverage reduced transmission, increase in average age of infection of remaining susceptible

• Children miss natural disease and vaccination and may enter reproductive age susceptible to rubella

• WHO policy (2000) – > 80% MCV1 coverage to the national routine (childhood) program

Minimum Coverage

• WHO policy (2000) – > 80% MCV1 coverage to the national routine (childhood) program

• Re-evaluate the 80% MCV1 cut-off in relationship to the accumulated experiences in countries and regions

Dynamics of ρ (short term)

Routine + 4 yr SIA + starting campaign 1-14 yr olds

Changes in ratio of CRS cases for R0=10, and 40 births per 1000 per year (i.e., as in AFRO region)

0100200300400500

2005201020152020202520302035204020452050

0% 60% 70%75% 80% 85%

Vaccination coverage (%)Year

Cumulative CRS incidence ratio

CRS incidence/100,000 livebirths

0

100

200

300

400

500

2005 2010 2015 2020 2025 2030 2035 2040 2045 2050

0.00.20.40.60.81.01.21.41.61.82.0

2005 2010 2015 2020 2025 2030 2035 2040 2045 2050

Bangladesh (low-medium birth rate, medium transmission)

0

50

100

150

200

2005 2010 2015 2020 2025 2030 2035 2040 2045 20500.00.20.40.60.81.01.21.41.61.82.0

2005 2010 2015 2020 2025 2030 2035 2040 2045 2050

Pakistan (medium birth rate, medium transmission)

0

100

200

300

400

500

2005 2010 2015 2020 2025 2030 2035 2040 2045 2050

0.00.20.40.60.81.01.21.41.61.82.0

2005 2010 2015 2020 2025 2030 2035 2040 2045 2050

Zambia(high birth rate, low-medium transmission)

0

20

40

60

80

100

2005 2010 2015 2020 2025 2030 2035 2040 2045 20500.00.20.40.60.81.01.21.41.61.82.0

2005 2010 2015 2020 2025 2030 2035 2040 2045 2050

Ethiopia (high birth rate, high transmission)

Draft Recommendations for minimum coverage threshold

• For countries that want to introduce– Must have a well functioning program that is committed

to sustaining rubella vaccination program long term– Well functioning programs should achieve MCV1

coverage 80% using WHO/UNICEF estimates either through routine or campaign or, if program doesn’t have 80%, be committed to improve immunization program.

– Point out it is OK to give at 9 months – same as the previous position paper

Summary

• Since the 2000 PP, several changes have occurred prompting an updating of the PP.

• WG was established in 2010• Using the experiences from the regions and countries,

several different phases (Goals) and corresponding strategies were developed

• With the re-evaluation of the minimum coverage threshold, countries may introduce RCV into routine childhood program if they can achieve an 80% MCV1 threshold either through routine or SIA