Email from Dr. Francis Collins, NIH Director, to Robert F. Kennedy, Jr., 6/11/17

From: Collins, Francis
Date: June 11, 2017 at 12:44 PM PDT
Subject: Follow up on vaccine data accessibility

To: Robert Kennedy Jr.

Dear Bobby,

Thank you again for your visit to NIH, for bringing along other colleagues, and for taking the time to share your point of view about vaccine safety. Following the meeting, we spent some time looking into your questions regarding access to the Vaccine Safety Datalink (VSD). You made a case for this resource to be more accessible.

It seems, based on our explorations of the VSD, it is actually fairly accessible for research use — although it does require a request for data access, IRB review, and travel to data enclaves in Atlanta or Hyattsville to work with the data. This is not dissimilar to the model NIH uses for protection of similarly sensitive, identifiable data, such as human genomics data or the data we expect to collect through our All of Us research program cohort. In our view, this model seems to strike an appropriate balance between accessibility of these data for studies on vaccine safety and privacy protections for the human participants from which the information originates.

We also looked into the suggestion of using the VSD for a comparative study of unvaccinated and vaccinated individuals, as well as the IOM report that was cited in support of that suggestion. In fact, it appears that the IOM did not endorse this idea (as seen from the excerpt below) and our research into the VSD confirmed that unimmunized individuals do not represent a large enough proportion of the data to provide appropriate power for such an approach:

“A small percentage of the US population receives no recommended childhood immunizations for reasons ranging from religious or philosophical beliefs, such as followers of Christian Science and some in US Amish communities, to health reasons, such as children with certain conditions, to personal convictions about the safety of vaccines. It has been suggested that such populations could serve as a naturally occurring unimmunized group in designing a new prospective cohort study. However, such a study would have limited utility to accurately assess differences in health outcomes between unimmunized and fully immunized children. First, there are questions regarding the potential size and resulting statistical power for such a study. Because some Amish communities and other potential naturally occurring unimmunized populations have relatively few unvaccinated children, the sample population of unimmunized children who could be recruited would likely be too small to provide adequate statistical power, particularly for very rare outcomes.

Furthermore, the study would need to account for the many confounding variables that distinguish distinct subgroups of naturally occurring unimmunized populations from the rest of the US populations, including lifestyle factors and known genetic variables that may play a role in the development of allergies, asthma, and other conditions. For example, data from the National Immunization Survey have shown that unimmunized children are characteristically different from children who are under-immunized or fully immunized on the basis of race, gender, socioeconomic status, and parental concerns. For all these reasons, the committee does not recommend the pursuit of prospective cohort studies with distinct subgroups of naturally occurring unimmunized populations (such as those who decline immunizations due to membership in specific religious or cultural groups).”

I would note that the IOM committee also evaluated the possibility of using a randomized controlled trial to study health outcomes in vaccinated versus unvaccinated children. The IOM reconfirmed a finding made by National Vaccine Advisory Committee (NVAC), that conducting a randomized controlled trial that required some children to be assigned to receive fewer vaccines than the recommended schedule would be unethical, because it would put children at risk of severe preventable diseases. This is a conclusion with which my NIH colleagues and I strongly agree.

I hope this additional information is helpful.

Best regards,
Francis