Some of the views expressed in the following notes on newly approved products should be regarded as preliminary, as there may have been limited published data at the time of publication, and little experience in Australia of their safety or efficacy. However, the Editorial Executive Committee believes that comments made in good faith at an early stage may still be of value. Before new drugs are prescribed, the Committee believes it is important that more detailed information is obtained from the manufacturer's approved product information, a drug information centre or some other appropriate source.
Typhim Vi (Pasteur Merieux)
0.025 mg/0.5 mL in single dose pre-filled syringes
Indication: prevention of typhoid
Travellers to areas where typhoid fever is endemic should be advised to avoid potentially contaminated food and water and be offered vaccination. Immunisation can be achieved with an oral vaccine containing live attenuated bacteria or an injection of heat killed bacteria. The injectable vaccine gives up to 80% protection for approximately 3 years after two doses. However, adverse reactions are common. This new product aims to produce immunity with fewer adverse effects.
The vaccine is made of purified Vi polysaccharide from the capsule of Salmonella typhi. A single intramuscular dose will protect nearly 80% of vaccinees for 3 years.
The most common adverse events are reactions at the injection site. However, systemic reactions including fever, headache, malaise and nausea can occur. This vaccine appears to cause fewer serious adverse events than the whole cell vaccine, but this needs to be confirmed with wider experience after marketing.
The vaccine is not suitable for small children as the polysaccharide antigen does not induce an optimal response in those under 18 months of age.
