Vaccines are weakened versions of viruses that, when introduced into the body, allow the immune system to easily build up antibodies to a particular virus without actually becoming infected. However, some patients suffer from a weakened immune system and can be put under pressure when given vaccines. New research is focusing on developing an influenza vaccine that is a live version of the virus, but with an essential amino acid removed, rendering it unable to infect its host, but still inducing the antibody-building immune response desired when administering a traditional vaccine.
Longlong S, H Xu, X Zhou, Z Zhang, et al. Generation of influenza A viruses as live but replication-incompetent virus vaccines. Science. 2016. DOI:10.1126/science.aah5869
Timmer J. Virus engineered to rely on artificial amino acids, used as vaccine. Arstechnica UK website. http://arstechnica.co.uk/science/2016/12/virus-engineered-to-rely-on-artificial-amino-acids-used-as-vaccine/. Published online December 2, 2016.