Did a then unknown virus, HHV-6/7, give rise to the whooping cough vaccine controversy of the 1970s?

During the 1970s there was a gross loss of public confidence in infant diphtheria-tetanus-pertussis (DTP) vaccination in the UK. As well as febrile reactions and convulsions, permanent neurological damage was ascribed to the pertussis component of the vaccine, and those concerns resonated worldwide. The subsequent recognition of human herpes virus 6 (HHV-6) and 7 (HHV-7) as common sources of fever in infancy suggests that they were the main underlying cause of what was reported as DTP constitutional side-effects. With more precise data on the incidence of HHV-6/7 and other virus infections in early life it would be possible to model the concurrence of viral illnesses with routine immunizations. Adventitious viral infections may be the cause of side-effects ascribed to the numerous childhood immunizations now being given.

Can postexposure vaccination against smallpox succeed?

What can be achieved by the vaccination of individuals exposed to smallpox virus after release of the virus by bioterrorists? There exist several past sources of information on postexposure vaccination failures from which it may be inferred that prompt vaccination of contacts (i.e., individuals exposed to smallpox) often prevented smallpox altogether, that revaccination of previously vaccinated individuals at any time during the first week of the incubation period was largely protective, and that revaccination done even as late as the second week of the incubation period attenuated disease and prevented most deaths. Primary vaccination done within 4 days of exposure was also usually protective at least from serious illness. Modern contingency planning against the release of smallpox virus during a bioterrorist attack should therefore include the capacity for prompt tracing and (re)vaccination of all contacts. Because a growing majority of the population has never before been vaccinated against smallpox and, so, may be unreachable within 4 days, anticipatory vaccination of sections of the populations of potential target countries should be considered if the bioterrorist threat intensifies.

Five postulates for resolving outbreaks of infectious disease.

Outbreaks of infection challenge the surveillance of infectious disease, but they also offer opportunities to improve and refine it. An outbreak may be the first sign of an emerging pathogen or it may draw attention to a new risk group or route of infection. Postulates analogous to those used a century ago by Robert Koch to prove the microbial aetiology of infectious diseases can be employed to verify the existence of an outbreak, demonstrate its cause and pinpoint its origins. In doing this, high-resolution molecular finger printing of micro-organisms has now assumed a crucial role. Without formal analysis based on postulates, the existence, extent and source of outbreaks may be overlooked and public health interventions misapplied or lost.

Anticipating smallpox as a bioterrorist weapon.

The treat of bioterrorism means it is important to be able to diagnose smallpox. The responsibility for the initial recognition of cases lies with clinicians, and early diagnosis is the key to the successful control of an outbreak. Unless rapidly contained, a bioterrorist release of smallpox would constitute not just a national but a global threat to health. This brief review sets smallpox in its modern context as an infection potentially spread by bioterrorists and recommends sources of information from the twentieth century that will assist clinicians in diagnosing the disease.

The new cell culture smallpox vaccine should not be offered to the general population.

Cell based smallpox vaccines are to be welcomed, but any decision to vaccinate whole populations must await firstly better intelligence about the gravity of the threat from bioterrorists, including their ability to release smallpox in such a way that wide dissemination could take place; secondly evidence that vaccines grown in cell culture are protective and safe; and thirdly that the vaccines would be generally acceptable and their introduction would not compromise the rest of national immunisation programmes. Smallpox vaccination should not be offered to the general population until these uncertainties have been resolved, by which time bioterrorism might possibly have been overcome or the development of antiviral treatment might have made renewed smallpox vaccination unnecessary. Meanwhile, preparations for rapid deployment of the historically well-tried containment measures at the epicentres of any smallpox release should proceed, their effectiveness should be tested, and their adequacy kept under review.