Comparative trial of live attenuated measles vaccine in Hong Kong by intramuscular and intradermal injection.

Between April and July 1966 a comparative trial of two live attenuated measles vaccines (Schwarz and Beckenham 31), given intramuscularly or intradermally, was conducted in Hong Kong. Some 910 non-immune children completed the trial. The Beckenham 31 vaccine caused significantly more complications than Schwarz vaccine, but it also resulted in a much higher mean antibody titre by both intramuscular and intradermal injection than did Schwarz vaccine. The seroconversion rates were satisfactory for both vaccines given intramuscularly but not for either given intradermally (at one-fifth the recognized intramuscular dose).The authors suggest that either vaccine may usefully be given for measles prophylaxis. The choice between Beckenham 31, with a higher complication rate and higher antibody levels, and Schwarz, with fewer complications but lower antibody levels, would depend on the type of community, the adequacy of the medical services, the severity of measles and an assessment of how either vaccine, with its known complications, might affect other immunization programmes.