England’s public health body has been accused of giving hundreds of thousands of cancer patients “misleading and dangerous” advice over the level of protection they can expect after receiving their Covid vaccine. There were calls yesterday for Chris Whitty, England’s chief medical officer, to intervene and correct a widely reported statement from Public Health England (PHE) stating that a double vaccination was “highly effective in clinical risk groups”. In a furious letter, seen by the Observer, Blood Cancer UK’s chief executive, Gemma Peters, said she was “deeply disturbed” by the press statement, which covered the findings of a recent study into vaccine responses. She said that its “confident, definitive assertions” about the level of protection given to the UK’s 230,000 blood cancer patients could not yet be supported by the “wider body of evidence on vaccine efficacy in the immunocompromised”. She warned that the assurances risked giving vulnerable patients “false assurance that could lead them to take dangerous risks”. She added: “I cannot tell you how disappointed I am to see the public body responsible for protecting people’s health acting in a way that recklessly risks the health of some of the most vulnerable people in our country. “Given all the above, we believe Public Health England has a duty to people with blood cancer to publicly retract this study as soon as possible, and to contact every journalist it was sent to. For clarity, we have no issue with the study itself, but with the way it has been represented in the press and the subsequent media coverage.” The PHE press statement, released on Friday, stated in the headline that vaccines were “highly effective in clinical risk groups”. However, Blood Cancer UK said that the study it is based on makes clear that more research is needed in the immunocompromised group, making it “impossible to justify such a sweeping and definitive headline”. It also states that vaccines offer similar protection to the immunocompromised as in other risk groups, but the study it is based on states: “We see reduced S-antibody response and reduced VE [vaccine efficacy] among the immunocompromised group, though VE in this group is much higher after the second dose and confidence intervals overlap with those in non-risk groups.” The press release gives no caveats to the sample size, despite the study only including a relatively small number of immunocompromised people. The charity also said that the release treated all immunosuppressed people as the same in terms of their risk, although that is not the case. It is understood that when contacted by the charity, PHE initially said it was standing by its original press statement. “I appeal to you to change your mind,” Peters states. “I fear the media coverage from your press release will have already done harm to important public health messaging, but I believe a swift retraction can mitigate much of that damage.” The novelty of Covid-19 means there remains a lot of uncertainty about how effective vaccines are for them, but it is known that people with blood cancer do not have as strong a response to other kinds of vaccines. Last night PHE partially revised its press statement: “Within these clinical risk groups, there will be people with more severe forms of illness – particularly in the immunosuppressed group – who may not respond as well to the vaccines, and we recommend they seek advice from their specialists.” However, it said that it was important that at-risk groups knew that it was worthwhile receiving two vaccinations because there was evidence it could provide them with protection. Blood Cancer UK welcomed the clarification, but said that the overall release remained misleading. A PHE source said that the study that the release was based on did find that for those who are immunosuppressed, vaccine effectiveness after a second dose is 74%, with similar protection to those who are not in a risk group. This rises from 4% after a first dose.