A mass vac­ci­na­tion pro­gram moves ever closer. Orders have been placed; pri­or­ity groups iden­ti­fied. There will be enough swine flu vac­cine to inoc­u­late the entire pop­u­la­tion, start­ing with NHS staff, in an attempt to halt the spread of the dis­ease and save lives.

Is all this really nec­es­sary? To start with, swine flu is far milder than we first feared, so the case for vac­ci­nat­ing mil­lions of healthy adults against a dis­ease that is no more unpleas­ant than a bad cold is ques­tion­able. There is a stronger argu­ment for vac­ci­nat­ing those at greater risk, such as those with lung, heart or kid­ney dis­ease, those with sup­pressed immune sys­tems (such as those on can­cer treat­ment), preg­nant women and chil­dren under 5 — but only if the vac­cine works and is safe. But there are seri­ous doubts about this.

Rush­ing the vac­cine on to the mar­ket means we will have no idea how effec­tive it is, although we do have a body of research on the effec­tive­ness of flu vac­cines in gen­eral, which gives some idea of what we might expect from the swine flu vac­cine. Pro­vided that we have matched the vac­cine well with the virus, it is likely to be up to 80 per cent effec­tive in healthy adults, the group at least risk from the virus.

A num­ber of tri­als have looked at the effect of flu vac­ci­na­tion on children’s asthma and have failed to demon­strate any ben­e­fit; one trial even sug­gested that the vac­cine made asthma worse. There is no good evi­dence that the vac­cine helps those with chronic health prob­lems or preg­nant women. How­ever, we do know that the immu­ni­sa­tion offers no more than a mod­est ben­e­fit in the elderly; indeed, the effec­tive­ness of the vac­cine is known to decrease sharply after 70 years of age.

The first vac­cines are expected to arrive in the UK by the end of next month. It will be some weeks later before they have gone through the min­i­mal safety test­ing nec­es­sary to con­sider offer­ing them to the gen­eral pop­u­la­tion. Real­is­ti­cally, it is unlikely that suf­fi­cient doses will arrive to vac­ci­nate sub­stan­tial num­bers until the end of the year.

Full story at Times Online