The JCVI states that a key reason for not making public all the evidence it uses in making its decisions is that making evidence public would lead to scientists refusing to send their work to the committee before it was published in a peer-reviewed journal and this might then lead to adverse outcomes.[1] Can the JCVI give some examples of where the use of unpublished evidence by the JCVI has resulted in decisions that have led to improved health outcomes or reduced mortality? Can they also supply evidence that academics would refuse to submit unpublished evidence if they knew this would be made public?

The JCVI also states that the processes the committee uses are "at least as robust as those of scientific journals”. However, the peer-review processes used by journals are flawed, errors in journal articles are common, and many factual errors and methodological problems are often not detected until after publication of an article.[2] Can the JCVI expand on how it aims to address these issues in the unpublished evidence it receives?

I would expect the JCVI to have substantially more rigorous procedures for peer review than scientific journals because the decisions the committee reaches have major implications for public health, health outcomes, and health care spending. There is a degree of subjectivity in how decisions on immunisation policy are reached. For example, chickenpox (Varicella) vaccination in children is part of the immunisation schedule in the USA but not in the UK.[3] Hence, immunisation committees in different countries can look at the same evidence but sometimes reach very different conclusions about immunisation policy. Public policy making is not an exact science but should as far as possible be based on robust, publicly available evidence that can be fully assessed by external stakeholders.

1.http://www.bmj.com/content/345/bmj.e5313?tab=responses

2. Majeed A. How should medical journals deal with errors? JRSM 2012;105:51-52.

3. Centers for Disease Control and Prevention. Child, Adolescent & "Catch-up" Immunization Schedules. http://www.cdc.gov/vaccines/schedules/hcp/child-adolescent.html

Conflict of interest: As an academic primary care physician, I am strongly supportive of evidence-based immunisation programmes.

Competing interests: None declared