Vaccination policies: individual rights v community health

The goal of a rubella vaccine programme is to reduce the occurrence of the congenital rubella syndrome. In this week's BMJ, Panagiotopoulos et al describe the history of the use of rubella vaccine in Greece and show that partial vaccine coverage led to a period in which susceptibility to rubella among childbearing women was actually increased (p 1462).¹ Therefore in 1993, an epidemic year for rubella in Greece, the incidence of rubella in childbearing women was higher than in previous epidemics, and the incidence of congenital rubella increased. What lessons can we learn from this failure?

Around the world the effectiveness of rubella vaccine programmes has varied. The rubella vaccine, which was first introduced in the United States in 1967, was very effective in reducing the annual number of babies with congenital rubella syndrome from an estimated 20 000 in 1964 to 7 in 1983.² The US had introduced the vaccine in a three step programme—that is, recommending vaccination of all infants at 12-15 months of age, screening women of child bearing age for rubella immunity, and vaccinating those susceptible to rubella. Initially in the United Kingdom the vaccine was recommended only for schoolgirls aged 10-12 years and susceptible women. This strategy had little impact on the incidence of congenital rubella syndrome. So in 1988 the British authorities changed to follow the US strategy. The incidence of congenital rubella syndrome remains low in the UK.³ In Japan schoolgirls receive rubella vaccine, but this has had little impact on the incidence of congenital rubella syndrome.⁴ Many developing countries have not used rubella vaccine routinely. In the English-speaking Caribbean, they are embarking on a one time mass campaign targeting males and females aged 5-39 years followed by routine use of measles, mumps, and rubella vaccine in early childhood.⁵ The effectiveness of this programme remains to be determined.

The Greek programme failed because it was given only to children with no attempt to protect adolescents and young women and no attempt to obtain high coverage. Yet if the public in Greece becomes aware that the risk of congenital rubella syndrome increased after the start of an immunisation programme it may become more difficult to institute a more effective vaccination programme and convince the public that more immunisation is better.

Public opinion can significantly affect vaccine uptake and consequently disease prevention. This was demonstrated most clearly with pertussis vaccine in the UK.⁶ In the early 1970s uptake of diphtheria, pertussis, and tetanus vaccine in the UK was 81% and the incidence of pertussis was low. After a report in 1974 ascribing neurological reactions to the pertussis vaccine the public lost confidence in the vaccine and uptake fell to 31%: pertussis epidemics followed.

In the developed world individual rights are given a high value, and antivaccine campaigners capitalise on the perspective of the individual, whereas public health perspective is based on the benefits for the community. If, because of a vaccine programme, the incidence of the disease has become low then the risk of disease for an individual is low but the risk of adverse effects from the vaccine is unchanged. Therefore for the individual, protection from disease by “herd immunity” may become the safest option because it avoids the risk from the vaccine. On the other hand, from the public health perspective, avoidance of vaccination is clearly not in the best interest of public because herd immunity diminishes as coverage falls. To persuade individuals to continue to be vaccinated when the vaccine programme has successfully reduced the incidence of disease requires that the vaccine have few adverse effects and that the individuals also value the community benefit.

Some of the concerns about the safety of the components of the measles, mumps, and rubella vaccine have been confirmed⁷and others are still speculation.⁸ Reports of an association between vaccines and adverse outcomes get much public attention, and it often becomes difficult to determine whether the public is getting the appropriate information for an informed decision. Recently the possible association of measles vaccination with ileal lymphoid nodular hyperplasia and developmental disorders was reported.⁹ In the flurry of correspondence criticising this paper, several wrote of the potential harm to public health vaccination programmes because of individuals becoming aware of this possible but unproved association. It was implied that individuals might now perceive the risk from measles to be outweighed by the risks of adverse effects from the vaccine. The recurring challenge for public health authorities is to find the best way to communicate with the public, so that they truly are informed on the relative risks and benefits of a vaccine programme.

Can the public and individual interests be served simultaneously? This can be achieved when a vaccine programme is started. At that point the disease incidence is high and the relative rate of vaccine adverse effects low. However as the vaccine programme becomes more successful in eradicating the disease, public and individual interests may diverge unless the vaccine has no adverse effects or the programme is so successful that the disease is eliminated and the vaccine programme can be discontinued. This was achieved for smallpox. However, in a voluntary programme it may always remain difficult to achieve a high enough uptake to achieve elimination for congenital rubella syndrome because some individuals will perceive the risks of vaccination as outweighing the benefits and decline vaccination. But one lesson from the Greek experience is not to introduce vaccination programmes half heartedly—either in terms of the evidence underlying the policy or in systematically promoting it.

Papers p 1462