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US encourages flu jabs for infants aged under 2

Deborah Josefson, Nebraska

Infants and children aged under 2 years are extremely susceptible to influenza virus and should receive flu jabs, says the vaccine advisory committee of the US Centers for Disease Control and Prevention.

The Advisory Committee of Immunisation Practices is urging flu vaccination of infants aged 6 months to 23 months, starting at the beginning of the next flu season (autumn 2002-3).

Although the committee fell short of making a full recommendation, it is expected to make the recommendation official within three years, pending the outcome of studies of the effect of more vaccines on parents and providers. Infants already receive about 20 immunisation injections.

Currently, flu vaccination is recommended for elderly people aged 65 and over, healthcare workers, pregnant women, and people who are chronically ill. Patients with respiratory problems such as asthma, emphysema, and chronic obstructive pulmonary disease and those with renal failure, heart failure, and diabetes are especially vulnerable to flu. Infants also represent an immunocompromised group, as their immune systems are inexperienced, lacking the antigenic exposure acquired through time.

The vaccine advisory committee based its new guidance on the results of two recent studies which found that babies aged 6-23 months were at increased risk for flu related admissions to hospital.

One of the studies was led by Dr Keiji Fukuda, an epidemiologist on the vaccine advisory committee. Dr Fukuda analysed admissions data from thousands of previously healthy children aged 6 months to 18 years enrolled in managed care practices of Kaiser Permanente Medical Group in northern California and Group Health Cooperative health plan in Seattle from 1992 to 1997 (New England Journal of Medicine 2000:342:232-9).

Overall, he found that children aged under 2 were 12 times more likely to be admitted for respiratory illnesses than those aged 5-17 years.

The other study was led by Dr Kathleen Neuzil, an infectious disease specialist at the University of Washington in Seattle. Dr Neuzil followed children younger than 15 years old enrolled in the Tennessee Medicaid programme from 1973 to 1993 (New England Journal of Medicine 2000;342: 225-31).

Dr Neuzil's team found that infants aged under 1 year were as likely as elderly and high risk groups to be admitted for flu.

(Credit: CDC/BARBARA RICE) Those babies most at risk of flu should receive their vaccination first, preferably by October