1993 whooping cough vaccine article

Whooping cough vaccine ‘should be replaced’

Whooping cough vaccine administered in the West is a ‘relatively crude’ tool and overdue for replacement, argues a leading scientist. Stanley Plotkin, who played a key role in the development of vaccines against rubella and rabies, claims that Japan has already switched to more sophisticated alternatives and believes the West will soon follow suit.

Whooping cough, or pertussis, is an extremely infectious disease that can kill. Paroxysms of coughing can last for up to three months, and the coughing can cause breathing problems, vomiting, and a lack of oxygen that can lead to brain damage. Until the existing vaccine was licensed in 1949, 6 out of every 100 000 people in the US died from the disease each year out of the 150 who were infected. After the vaccine arrived, the number of cases dropped dramatically (see Graph).

In the mid-1970s, many parents refused to have their children vaccinated, after some highly publicised cases of brain damage and death. As a result, only a third of children in Britain were vaccinated – and two epidemics of whooping cough followed. Today, 90 per cent of parents choose to have their babies vaccinated rather than risk them catching the disease, and the number of cases has fallen again. But many parents remain nervous about the potential side effects of the vaccine.

The existing pertussis vaccine is based on a suspension of the whole, killed bacterium, Bordetella pertussis, which causes the disease. It is known as whole-cell vaccine. Plotkin, who is medical and scientific director of Pasteur Merieux, the world’s biggest manufacturer of vaccines, stresses that the whole-cell vaccine is safe, but he believes it is outmoded. ‘It is a relatively crude vaccine to be using in 1993 and it can produce convulsions and fever. So there is pressure to have a better vaccine.’

In the early 1980s, Japan developed and licensed several alternatives based on purified fragments of B. pertussis, known as acellular vaccines. The US Food and Drug Administration has licensed an acellular pertussis vaccine, but only for extra booster doses and only for certain age groups. In Britain, a trial of two acellular vaccines is under way.

A massive international trial in Sweden is currently comparing 13 acellular vaccines – including one developed by Pasteur Merieux – in 50 000 people. Initial findings are encouraging, say scientists. All studies have shown that the acellular vaccines produce far fewer convulsions, fever or other side effects, and that they give varying degrees of protection against infection.

‘It is clear that the major authorities – the US, the UK and France for example – are going to wait for the results of the Swedish study,’ says Plotkin. ‘The public health authorities feel that they need more evidence before they run the risk of increasing the rate of pertussis, but it should be noted that Japan has successfully limited pertussis solely with the use of acellular vaccines and I think we can expect the same thing here.’

However, some scientists are not satisfied that there is enough evidence yet from Japan to justify the newer vaccines. Scientists at the Centers for Disease Control in the US recommend that doctors continue to give whole-cell vaccine until there is an alternative that has demonstrated ‘equivalent or higher’ levels of protection.

A spokeswoman for the Public Health Laboratory Service in London said there was ‘insufficient’ data from Japan to conclude that acellular vaccines were better than the whole-cell preparation. ‘We are moving ahead with trials, and when new products are available we will reconsider the position,’ she said.

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