2002 Dr David Salisbury: Managing vaccine adverse effects

The 10th annual John Snow Society Pumphandle lecture, given by Dr David Salisbury, focused on the public’s concern for vaccine safety; where this fear comes from and how the Department of Health tackles these problems.

Dr David Salisbury is a Principal Medical Officer of the Communicable Disease Branch, the Department of Health, London, where he leads the group responsible for immunisation and communicable diseases. In addition to his UK responsibilities, he works extensively for the WHO on the Global Programme for Vaccines. He serves on three Regional Commissions for the Certification of Elimination of Poliomyelitis. Dr Salisbury graduated from London University in 1969. He trained as a paediatrician at Oxford and at the Hospital for Sick Children, Great Ormond Street, London.

He also has an honorary Senior Lectureship in Child Health at Kings College, London. He is an honorary visiting fellow at the Wellcome Centre for Infectious Disease Epidemiology, University of Oxford, is a Fellow of the Royal College of Physicians, Fellow of the Royal College of Paediatrics and Child Health, and a Fellow of the Faculty of Public Health Medicine.

Dr Salisbury was made a Companion of the Order of the Bath in the Queen’s 2001 Birthday Honours.

Dr Salisbury stressed that serious adverse reactions to vaccines occur extremely rarely. However, when they do occur they are a cause for concern and attract considerable media attention. He discussed how vaccine safety scares often arise from reports (often presenting data collected through active searching) where a series of cases of the adverse vaccine reaction have occurred. These reports, referred to by Dr Salisbury as ‘stamp collections’, often get published in professional journals, despite having little relevance to the background risk, and should not be taken as evidence in support of an association. However, said Dr Salisbury, they may form the basis of a hypothesis that should be then tested by a properly designed study against the criteria of biological plausibility.

Dr Salisbury gave the following example to highlight the significance and major knock-on effects of these ‘stamp collections’: In 1994 the UK’s Department of Health ran a nationwide immunisation campaign for the measles-rubella vaccine. All school children, aged 5 up to 16, were immunised in the space of six weeks. However, there was a cluster of cases of the disease Guillain-Barré syndrome occurring post-immunisation. These cases were picked up by media journalists, who made it into headline news and this is where the hypothesis that there might be a causal association between measles vaccination and Guillain-Barré syndrome began. This then became a scare over the measles vaccination and individual stories of the vaccination victims with adverse effects came to light. In response to this particular scare, Dr Salisbury explained how the department of Health tested the hypothesis independently by setting up a collaborative study with the Pan America Health Organisation. In response to this particular scare, Dr Salisbury explained how the Department of Health tested the hypothesis independently. The tests were carried out here in the UK and in the Americas. The risk of Guillain-Barré syndrome, detected through acute flaccid paralysis surveillance, was compared in both measles campaign periods and non-campaign periods. The results from this study demonstrated that there was no significant risk of Guillain-Barré syndrome following measles vaccination. So, concerns start in the professional press, but it doesn’t take long before these seep into the wider media. Extensive reportage in the media gives any vaccine scare story the potential to travel extremely fast all over the world. However, negative results do not attract media attention and these are poorly represented in the newspapers.

As the Principal Medical Officer of the Communicable Disease Branch at the Department of Health, Dr David Salisbury needs to deal with all of the above on a regular basis. The strategy the Department has in place is to try to predict scares, then try to prepare for them, alongside aiming to be proactive and achieving positive responses. Although they cannot always predict vaccine safety scares, the Department of Health does have a reasonable idea of the topics that are likely to attract public interest. These, not surprisingly include autism, multiple sclerosis, multiple vaccines and immune overload, which all share the common features of uncertain manifestation and long latency that the public fears. The public expects authorities to prove that studies claiming vaccine risks are false, or the theories stand unchallenged.

In preparation, it is critical to gather as much information as possible and to find out if adequate data already exists that can answer the problem. If not, how feasible is it to collect new data? If the answer is we are awaiting results from these studies, then this does not reassure the public!

It is necessary to be proactive during a vaccine safety alert. Health professionals must be alerted promptly about the scare before the media reach them. However, this can often be difficult because of embargoes on publications. It is very easy for journalists to find a doctor who may give unhelpful comments, often based on ignorance, but that the public will believe. The Department of Health prepares information materials for all audiences. References are given to parents to add credibility. The information is targeted to the right health professionals and to the right parents at the right time.

In times of vaccine safety scares, positive responses from authoritative bodies are essential. The most important thing is to tell the truth and give clear messages. Parents do want to feel that they are making a choice, but very few will have sufficiently detailed knowledge to actually be making a fully informed decision. Dr Salisbury believes that a choice of risks should not be offered because it is very difficult to put into realistic terms the risks and benefits. In addition, it is important not to patronise parents by being the ‘expert’. Professional support has been shown to help reduce scares dramatically and, therefore, it is necessary to have contacts in these fields. For example, if a media doctor, especially one appearing regularly on morning TV, informs the public that a vaccine is safe, they will believe and trust this doctor.

As part of their communication research programme, the Department of Health carries out two nationwide surveys each year. One thousand mothers, with children under the age of three, answer a series of questions related to vaccines, where they get information from and who they trust in relation to vaccine information. The surveys are geographically representative and question mothers from all walks of life. An additional two surveys have been added to the annual programme which ask questions specifically related to the MMR vaccination. The results from these surveys help the Department predict, prepare, and be proactive.

In conclusion, Dr Salisbury said that the internet had become a ‘battle ground’ of information to be picked up by eager journalists, emphasising the point that poor scientific reports, that may not have been properly scrutinised, are now immediately available for all to see on the internet. We must concentrate on presenting the truth to parents, said Dr Salisbury, to allow them to remain confident with our vaccination programmes.

Following his excellent lecture Dr Salisbury took numerous questions from the audience. Members of the John Snow Society then gathered in the John Snow pub in Soho for the annual general meeting of the society.