CSU 14/2009: QUERY TO READERS/ INTRODUCTION OF RUBELLA VACCINATION/ SMALLPOX ERADICATION

Monday, 30th of March 2009

CHILD SURVIVAL UPDATE 14/2009: QUERY TO READERS/ INTRODUCTION OF RUBELLA VACCINATION/ SMALLPOX ERADICATION

QUERY TO READERS

Now that dozens of countries have years of experience with annual or semi-annual mass deworming campaigns, do we have any published or unpublished data showing whether prevalence of intestinal helminths has declined in the countries where the campaigns took place?

1) RUBELLA VACCINATION POLICY

Rubella vaccination aims not at the prevention of rubella in general, but at the prevention of CRS, congenital rubella syndrome, which often has permanent effects on the offspring born after their mothers contract rubella during pregnancy.

Writing in 1998, while many Latin American countries were considering the introduction of rubella vaccination, Hinman and colleagues stated

'While the inclusion of rubella vaccination into routine childhood immunization will decrease rubella virus circulation among young children, it will not have immediate impact on the transmission of rubella among adults or the occurrence of CRS. A one-time mass campaign targeting both males and females 5 to 39 years of age with

measles-mumps-rubella or measles-rubella vaccine followed by the use of measles-

mumps-rubella vaccine in routine early childhood vaccination will prevent and control

both rubella and CRS promptly.'

(Hinman, AR et al, ‘Rational use of rubella vaccine for prevention of congenital rubella

syndrome in the Americas,’ Rev Panam Salud Publica. 1998 Sep;4(3):156-60).

2) THE CASE OF GREECE

The unintended impact of vaccinating only children against rubella is a shift in the age distribution of cases from children to adolescents and, occasionally, adults. With rubella, this may increase rubella cases among women of childbearing age, with resulting CRS in their offspring.

This subject is of special interest for countries now considering the introduction of rubella vaccination. The example of Greece is instructive. Here is the authors' summary of that country's CRS epidemic, from an article in Eurosurveillance:

'Greece experienced a large outbreak of CRS in 1993 [3]. There is evidence that this outbreak was the consequence of immunisation practices that had been followed. The measles, mumps and rubella vaccine (MMR) became commercially available in Greece around 1975, and started being administered to children of both sexes in their second year of life without adopting policies to protect adolescents and young women (emphasis added) or policies to attain high immunisation coverage of children - until 1989 when the MMR vaccine was introduced in the national immunisation schedule. During the 1980s, immunisation coverage for rubella remained consistently below 50% and the proportion of pregnant women susceptible to rubella gradually increased to around 20-35% in the late 1980s and early 1990s in urban areas. In 1993, when a major rubella epidemic took place in Greece, a shift in the age distribution of rubella cases towards older ages was observed (64% of cases were 15 years old or more), and the incidence of the disease in persons of childbearing age was higher than in any previous epidemic year. The congenital rubella outbreak that followed, with 25 serologically confirmed cases recorded (24.6 per 100 000 live births), was probably the largest in the country after 1950 [3].'

By contrast, countries that vaccinated their women of childbearing age against rubella before introducing infant rubella vaccination have not, to this reader's knowledge, seen the CRS epidemics of the kind seen in Greece.

Full text of the Eurosurveillance article is at http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=461

Greece's 1993 CRS outbreak was also the subject of an article in the BMJ, accessible online at http://www.ncbi.nlm.nih.gov/pubmed/10582926

A WHO/AFRO presentation on rubella is available at http://mail.google.com/mail/?ui=2&ik=be2d7c1066&view=att&th=1200e16aeb8b7c60&attid=0.1&disp=vah&zw

3) SMALLPOX ERADICATION

An interesting interpretation of the main elements of success in SEP is online at http://www.technet21.org/Articles/smallpox_eradiction.html Most veterans of smallpox eradication would agree that smallpox eradication was 'as much a triumph of management as of medicine.'

Good reading.