Americas region declared world’s first to eliminate rubella

Endemic transmission of rubella has been eliminated throughout the Americas due to widespread use of the MMR (mumps, measles, rubella) vaccine, according to an announcement by the Pan American Health Organization and the World Health Organization.

The press release and associated materials, including a factsheet on Rubella, are available here.

 

Dr James Cherry, Distinguished Research Professor of Pediatrics, David Geffen School of Medicine at the University of California, Los Angeles (webpage): 

Expertise: pediatric infectious diseases, epidemiology and vaccine prevention strategies of Bordetella pertussis worldwide

“Rubella has been easier to eradicate when compared to other diseases like measles because of two reasons. One, the vaccine is better, with a single dose demonstrating close to 98% effectiveness compared to around 95% for the measles vaccine. Secondly rubella is also less contagious compared to measles. The bad news is that rubella can circulate in the population for a while and can get missed because the symptoms are mild. An outbreak is recognized only when babies affected by congenital rubella syndrome (because the mothers were infected during pregnancy) show up.

“It is easy to accept what the Pan American Health Organization (PAHO) has said because the vaccine prevention program in the United States and the rest of the Americas has ensured that there are no endemic cases and the circulation is interrupted in the population. However, rubella is still widespread in other parts of the world including Europe. In order to completely eradicate rubella a global program similar to the one for polio has to be established.

“Regarding the PAHO’s claim that measles will be eradicated in the coming years, there is no endemic measles in the United States and hasn’t been for 15 years. The recent outbreak in California occurred due to importation from elsewhere. However the absence of endemic measles is threatened if the number of people immunized against the disease drops. We have been talking about measles eradication for 30 years. But it is widespread throughout the world and to completely eradicate it there has to be a global immunization program.”

 

Dr Arthur L. Reingold, Professor and Head of Epidemiology, School of Public Health, University of California, Berkeley (webpage)

Expertise: prevention of transmission of HIV in developing countries, intersection of HIV/AIDS and tuberculosis epidemics, emerging and re-emerging infections in the US and globally, sexual transmission of hepatitis C virus, vaccine-preventable diseases, and respiratory infections in childhood.

Elimination or rubella from one of the WHO regions of the world is a remarkable achievement in its own right, demonstrating what can be achieved when a vaccine of proven efficacy and safety can be widely administered to a target population. In addition, it is a demonstration that not only is regional elimination of an infection like rubella possible, but so is global eradication, if all regions of the world demonstrate similar commitment and have access to adequate resources. Global eradication of rubella would not only result in a marked decrease in congenital malformations/birth defects and their life long and expense consequences, but also would lead to the elimination of the need to continue to administer rubella vaccine anywhere in the world.

“The accomplishment also supports the contention  that regional elimination and global eradication of measles is possible, using the safe and effective measles vaccine that we currently have available, although measles virus  is more easily transmitted/more contagious than rubella virus, so higher levels of immunity across populations may be needed to achieve elimination and eradication. At the same time, however, the very large epidemics of measles that are recurring in Europe, Asia,and Africa, together with the inability of many countries to achieve high levels of coverage with two or more doses of measles vaccine, despite its low cost and wide availability, demonstrate that achieving measles elimination in a number of regions, and therefore achieving global eradication of measles, will not be easy, especially if commitment to these goals is not maintained, and even strengthened. Achieving global eradication of measles will be even more difficult  if concerns about the safety of measles  vaccine among  parents in various regions of the world cannot be addressed.”

 

Dr Walter A. Orenstein, Professor, Department of Medicine, Division of Infectious Diseases and Associate Director, Emory Vaccine Center, Emory University School of Medicine (webpage)

Expertise: evolution, emergence, transmission and pathogenicity of influenza viruses, vaccine safety and effectiveness. Dr Orenstein was the former director of the United States’ National Immunization Program.

“In 2001, rubella was declared eliminated in the US and in 2015, the Americas was declared free of indigenous rubella. However, as long as rubella viruses circulate anywhere in the world, there is the potential for importation into the Americas and re-establishment of transmission.

“Congenital Rubella Syndrome (CRS) occurs when a susceptible pregnant woman is infected by the rubella virus often leading to severe birth defects in the developing fetus including one or more of the following: deafness, congenital glaucoma and other eye defects, congenital heart disease, neurologic damage, diabetes, thyroid dysfunction as well as other abnormalities. CRS is one of the few known causes of autism, a cause of autism that can be decreased through vaccination.

“Prior to elimination of CRS in the Americas, it had been estimated that there were 16,000 to 20,000 cases of CRS born annually in Latin America and the Caribbean. As recently as November 2014, the World Health Organization estimated that 110,000 infants were born with CRS in the world each year. CRS can be prevented by vaccination against rubella.

“Rubella vaccine is highly effective. A single dose administered on or after the 1st birthday is about 97% effective in protecting against the disease. Further, rubella is less contagious than diseases like measles. The population immunity level thought to be needed to terminate transmission of rubella is 83-85% compared to 92-94% for measles. And rubella meets biologic criteria for being eligible for eradication: 1) humans are essential for maintaining the virus through transmission from one human being to another; 2) there are diagnostic assays to determine who is infected with rubella; 3) there is an effective intervention, rubella vaccine; and 4) there is proof of principle in termination of transmission in a wide geographic area (i.e., the Americas).

“However, there are impediments to global rubella eradication. First, much of the world has not documented the health burden of rubella in their populations. Second, there may be accumulated susceptible young adult populations who were not exposed to disease in childhood nor vaccinated. Third, rubella infection may be without symptoms in children who could silently spread the virus. Fourth, until polio is eradicated, it may be difficult to convince countries to take on another eradication program, especially if they do not recognize rubella as a burden in their country.

“Thus, a call for full rubella eradication is premature at this point but it is doable and hopefully will be considered once polio is eradicated and consideration is given to measles eradication. There are combined vaccines containing both measles and rubella vaccine viruses that can be used to protect against both diseases.

“Measles transmission has been terminated in the US since 2000 and in the Americas in 2002. All six Regions of the World Health Organization have goals to eliminate measles, a major step toward a global eradication goal. However, as was seen this year, as long as there are reservoirs of measles virus transmission elsewhere in the world, there is the risk for exporting the virus to the Americas leading the outbreaks and potential re-establishment of transmission. Thus, eradication has the potential not only to reduce serious disease including deaths in countries presently infected but also helps protect our own domestic health security. In essence, the US has both a humanitarian and a health security benefit in promoting measles control globally eventually leading to eradication.

“Difficulties with measles eradication include: 1) polio is not eradicated and countries may not be interested in taking on another disease eradication project at this time; 2) measles is highly contagious and requires very high immunity levels to terminate transmission. Thus, it is critical to reach very high levels of immunization coverage in all populations and population sub-groups to terminate transmission; 3) some countries, particularly in Western Europe do not perceive measles to be a serious disease compared to countries where measles exacts a terrible health burden such as sub-Saharan Africa. Eradication will require convincing all countries to work together to achieve the goal; 4) concerns about safety and particularly the relationship of the measles, mumps, rubella (MMR) vaccine and autism, now refuted in the scientific community, still contribute to parental hesitancy to be vaccinated. Nevertheless, once polio is successfully eradicated, there will be serious consideration for measles eradication. As recently as 2013, the WHO estimated 145,700 persons died of measles, most children < 5 years of age.”

 

Declared interests (see GENeS register of interests policy):

No interests declared.

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