5th Global Meeting on Implementing New and Under-utilized Vaccines, 22-24 June 2011
Workgroup 4. Delivery Strategies for Typhoid, JE, Rubella, and HPV Vaccines
At present, it is believed that 90% of the cases and deaths due to typhoid occur in Asia. There are currently insufficient data to make an assessment for Africa, but burden may be similar to Asia. Several typhoid endemic countries in Asia have initiated typhoid vaccination, using mainly the Vi polysaccharide vaccine. Interest is growing in other typhoid endemic countries to consider vaccination to complement efforts to improve water, sanitation, and personal hygiene practices.
Japanese Encephalitis (JE) represents a major cause of viral encephalitis in Asia and South Asia. Many countries have now initiated large scale vaccination programmes, mainly with the live attenuated SA14-14-2 vaccine. In some countries, immunization efforts are targeted to high risk areas.
Worldwide, approximately 120,000 infants are born with congenital rubella syndrome (CRS) with the highest burden in countries of SE Asia and Africa where rubella vaccine is not in use. In April 2011, SAGE noted that existing 2-dose measles vaccine delivery strategies provide a platform for advancing Rubella and CRS elimination through use of combined measles-rubella vaccine. There is limited experience with the introduction of rubella vaccine in less industrialized countries.
Cervical cancer is the second most common cancer in women with an estimated 529,000 new cases and 274,000 deaths each year. HPV vaccine offers a new tool for cervical cancer prevention. Optimal vaccine delivery strategies to routinely reach girls aged 9 through 13 years old with 3 doses in ways which are acceptable, affordable, and sustainable and which achieve high coverage are still being determined.
Since typhoid, JE and HPV vaccines need to be administered to a population that has not previously been routinely served by many immunization programmes, creating a new vaccine delivery platform will often be necessary.
Main Topics of Discussion
- For JE and typhoid, the main strategy was to focus on high risk groups or geographic areas with an initial catch up component followed by a routine programme. Because of the need to define high risk areas or populations, good data are required to define the at-risk populations. Country experiences with catch-up vaccination in high risk groups followed by routine immunization were shared:
- Nepal used a combination of targeting all ages in selected districts with the SA14.14.2 JE vaccine, and ages 1-15 years in the rest of the districts at high risk for JE for a catch-up campaign. This was followed by introducing the vaccine at age 1 year.
- Viet Nam used Vi Polysaccharide typhoid vaccine targeting 3-5 year old children, but at some stages even vaccinated children up to 10 years of age.
- For rubella two general approaches were pursued in using the vaccine:
- Wide age-range campaigns (9 months to 19 years in Laos, and 9 months to 15 years in Nepal) followed by Measles-Rubella (MR) vaccine introduction for first dose at 9 months.
- Offer MR vaccine to women of child-bearing age through routine services.
- Use MR vaccine in all subsequent follow-up campaigns.
- Monitor impact through rubella/CRS surveillance and coverage monitoring.
- For HPV vaccine:
- Rwanda introduced the vaccine in April 2011 by targeting girls attending Primary 6th grade through school-based vaccination and out-of-school girls aged 12 yrs through health centers.
- Argentina plans to introduce HPV vaccine in Sept 2011 and the target population will be 11 year old girls who will be vaccinated in health centers.
- Defining risk groups
- The requirement of high quality labs is critical but challenging for countries to maintain.
- Deciding on the highest age group to be included in the initial campaign is a function of resource availability.
- Donations (e.g. MR, HPV) need to be reviewed in light of their potential implications.
- Integrated and comprehensive programme needs need to be weighed against the ability of countries to implement such programmes (e.g. cervical cancer screening and vaccination with HPV)
- Operational costs for delivering vaccine need to be defined.
- There is a lack of international support for vaccines that are clearly beneficial to the most disadvantaged such as typhoid, JE, and rubella vaccines.
- Monitoring coverage of these vaccines outside of the regular EPI age range is difficult.
- Support countries with surveillance for diseases such as JE and typhoid where vaccine delivery is based on targeting high risk populations.
- Development of coordinated national cervical cancer prevention strategies which include primary (HPV vaccination), secondary (cervical cancer screening), and tertiary (treatment and palliative care).
- Perform assessment of sustainability when considering new vaccine introduction, particularly in countries where new vaccine introduction is dependent on donor support.
- Increase international support to scale up the introduction of these vaccines.