WHAT'S NEW THIS TUESDAY: FOUR ON VACCINES AND VACCINATIONS

Sunday, 14th of October 2012

• FOUR ON VACCINES AND VACCINATIONS
  
• VACCINATION OF HEALTH CARE WORKERS

‘Vaccination of health care workers to protect patients at increased risk for acute respiratory disease,’ Emerging Infectious Diseases, Volume 18, Number 8— August 2012

Gayle P. Dolan  , Rebecca C. Harris, Mandy Clarkson, Rachel Sokal, Gemma Morgan, Mitsuru Mukaigawara, Hiroshi Horiuchi, Rachel Hale, Laura Stormont, Laura Béchard-Evans, Yi-Sheng Chao, Sergey Eremin, Sara Martins, John S. Tam, Javier Peñalver, Arina Zanuzadana, and Jonathan S. Nguyen-Van-Tam

Author affiliations: University of Nottingham, Nottingham, UK (G.P. Dolan, R. Hale, J.S. Nguyen-Van-Tam); World Health Organization, Geneva, Switzerland (R.C. Harris, M. Mukaigawara, L. Stormont, Laura Béchard-Evans, Y.-S. Chao, S. Eremin, S. Martins, J.S. Tam, J. Peñalver); National Health Service Derbyshire County, Chesterfield, UK (M. Clarkson, R. Sokal); Health Protection Agency South West, Gloucester, UK (G. Morgan); Tokyo Medical Dental University, Tokyo, Japan (H. Horiuchi); and University of Bielefeld, Bielefeld, Germany (A. Zanuzadana)

Abstract below; full text, http://wwwnc.cdc.gov/eid/article/18/8/11-1355_article.htm

Health care workers (HCWs) may transmit respiratory infection to patients. We assessed evidence for the effectiveness of vaccinating HCWs to provide indirect protection for patients at risk for severe or complicated disease after acute respiratory infection. We searched electronic health care databases and sources of gray literature by using a predefined strategy. Risk for bias was assessed by using validated tools, and results were synthesized by using a narrative approach. Seventeen of the 12,352 identified citations met the full inclusion criteria, and 3 additional articles were identified from reference or citation tracking. All considered influenza vaccination of HCWs, and most were conducted in long-term residential care settings. Consistency in the direction of effect was observed across several different outcome measures, suggesting a likely protective effect for patients in residential care settings. However, evidence was insufficient for us to confidently extrapolate this to other at-risk patient groups.

• VACCINES VS VIRUSES

New York Times, 23 July 2012

Q. Why didn’t viruses like polio and other diseases mutate to become immune to vaccines?

A. “Bacteria mutate very well, but vaccines don't give viruses much of a chance,” said Dr. Paul A. Offit, chief of infectious diseases at the Children’s Hospital of Philadelphia.

The way it works with the measles vaccine, for example, is that a live, weakened form of the virus is given, so that the body develops antibodies directed against all 10 of the virus’s proteins and all the sites where it might attach to the body’s cells. “When the virus tries to infect you, it really doesn’t have a chance,” Dr. Offit said. “You attack it at all possible points.”

Polio has three serotypes, or types of surface proteins, but they were all in the vaccine. Mumps, German measles and chickenpox all have single serotypes.

It is different with bacteria, he said, because there are already resistant bacterial strains out there, so vaccination provides a fertile ground by eliminating sensitive strains, allowing resistant strains to thrive.

“With a virus, this never gets started,” Dr. Offit said. “I suppose if you were making a vaccine against one part of one protein, it might allow mutation, but we don’t give it a chance.”

There are two important exceptions, he said: influenza, which mutates so quickly that immunization one year does not protect from the next year’s strains, and H.I.V., which can mutate during a single infection.

C. CLAIBORNE RAY

A version of this article appeared in print on July 24, 2012, on page D2 of the New York edition with the headline: Vaccine vs. Virus.

• REDUCED PRICE ON ROTAVIRUS VACCINES

From conclusion; full text is at

http://www.who.int/bulletin/volumes/90/7/11-094656/en/index.html

The two major pharmaceutical compa­nies that manufacture rotavirus vaccines have recently offered to sell these vac­cines to the world’s poorest countries at greatly reduced prices. This is eloquent proof of the industry’s commitment to facilitating access to life-saving vac­cines. However, even at these lowered prices rotavirus vaccines would still be substantially more expensive than traditional childhood vaccines and the introduction and sustainment of a ro­tavirus vaccination programme would still be unaffordable for low-income countries. Thus, vaccine manufacturers need to be pressured to further reduce the price of their vaccines, and new sustainable financing opportunities for immunization programmes in low-income countries need to be identified. These pursuits should rank high on the agendas of international health and development organizations.

By reducing deaths from rotavi­rus-associated diarrhoea, universal access to rotavirus vaccines could greatly contribute to the attainment of the United Nations’ Millennium Development Goal of reducing child mortality. The international public health community should make every effort to ensure universal access to rotavirus vaccines.

• TWO ON FACTORS AFFECTING VACCINATION COVERAGE IN SUB-SAHARAN AFRICA AND IN INDIA

‘Contrary to expectation, we found children from urban areas were more likely to be unimmunised than those from rural areas . . .

‘The few currently available systematic reviews relevant to childhood immunisation programmes in sub-Saharan Africa show that parent reminder and recall systems [32] and mass media interventions [33] have the potential to increase immunisation coverage. Verbal, video, or provider-delivered communication tools may also increase parents’ understanding, especially if the tools are structured, tailored and interactive [34]. In addition, interventions to promote interaction between the community and health services may build trust and generate awareness and understanding of vaccination issues among parents.’

The reader of research findings from Malawi, Burkina Faso and Kenya will discover in each case dozens of published citations from district field research areas, in, respectively, Karonga, Ouagadougou, and Kilifi. In each case, national and international partners have set up reporting systems which permit monitoring of epidemiological trends over years, even decades. Readers of this homepage will remember an earlier write-up from Kilifi, at http://ije.oxfordjournals.org/content/early/2012/04/27/ije.dys062.full?etoc

and, from Ouagadougou, a tantalizing excerpt at  http://ije.oxfordjournals.org/content/early/2012/06/08/ije.dys090.extract?sid=4740d376-1835-4114-80f9-cbcf4eb2d172

Here is a write-up from Malawi.

KEY MESSAGES

Karonga HDSS is a health and demographic surveillance system of 35 000 individuals based on a validated and cost-effective community reporting structure.

Karonga HDSS was designed as a platform for epidemiological and clinical studies using well-established identification procedures enabling linkage to health and socio-economic data and archived biological specimens. Our capacity to re-identify individuals and to link children with both parents facilitates longitudinal investigations of individuals and families, spanning decades, including genetic relationships.

Current research areas include HIV, TB and other infectious diseases, and behavioural studies related to transmission, although in response to changing health priorities in Malawi, future plans include diversification to non-communicable diseases (e.g. hypertension and diabetes).

First published online: June 22, 2012