Children are likely to need two doses of swine flu vaccineBMJ 2009; 339 doi: http://dx.doi.org/10.1136/bmj.b3969 (Published 25 September 2009) Cite this as: BMJ 2009;339:b3969
Children are likely to need two doses of H1N1 influenza vaccine to achieve a full immune response, while most adults will need just one, the director of immunisation at the Department of Health has said.
Speaking at a briefing to announce that the estimated number of new cases of swine flu in England has almost doubled over the past week to 9000, David Salisbury said, “The data we have seen so far in healthy adults using one dose of vaccine is encouraging.” But he added that the data for paediatric doses was not so promising and that for children and some groups of adults two doses of vaccine may be recommended.
The government is still waiting for European regulators to license the two types of swine flu vaccine it has bought, although one, Pandemrix, has been recommended for marketing authorisation by the European Medicines Agency. The decision from the European Commission on formal licensing approval is expected soon, after which GPs will start immunising the specified priority groups, including healthcare workers and people with underlying health conditions. The other vaccine bought by the Department of Health, Celvapan, is still unlicensed.
Announcing the latest figures, Liam Donaldson, chief medical officer for England, said, “Everything suggests we are starting to see a second wave of cases.” He said he would have “preferred a longer breathing space” before numbers of cases started to rise this autumn in order to get the vaccination programme in place.
Although most cases continue to be mild, the total number of deaths in the United Kingdom related to swine flu has risen to 82. The weekly number of hospitalisations in England has also risen, from 143 last week to 218 this week. Of those patients, 25 are in intensive care. There has been an overall 20% rise over the past week in the rate of consultations for flu-like illness.
Most new infections and hospitalisations are in children and young adults. The number of schools in England reporting outbreaks this week was 66, although Professor Donaldson said that the true figure was likely to be much higher.
He also said that rates of infection of H1N1 flu are continuing to fall in the southern hemisphere and to rise in the northern hemisphere. France, which had few cases earlier in the summer, is now seeing a rapid rise in numbers infected.
The World Health Organization announced this week that regulatory authorities have licensed pandemic vaccines in Australia, China, Hungary, and the United States and that Japan and several European countries would soon follow. The length of the approval process depends on each country’s regulatory pathway and the type of vaccine being licensed.
WHO now estimates that the global production capacity of pandemic vaccine is three billion doses a year, down from the five billion doses it estimated in May. But it said that early data from clinical trials indicate that a single dose of vaccine will be sufficient to confer protective immunity in healthy adults and older children, so effectively doubling the number of people who can be protected with the current supplies. However, WHO warns that these supplies will still be inadequate to cover the world’s population of 6.8 billion people.
Cite this as: BMJ 2009;339:b3969