In many states subsequent vaccinations are good for three years. (vetinfo.com)
The «primer» pandemic influenza vaccine — made from live but weakened virus — introduces the immune system to H7N9 influenza virus, and subsequent vaccination with the «booster» inactivated virus vaccine recalls a more robust immune response. (sciencedaily.com)
If passive immunization is given subsequent vaccinations must be delayed due to interference from passive immunoglobulins. (lowchensaustralia.com)