Mass flu vaccination is not only useless, as Margaret McCartney suggests; it may do real harm, opportunity cost aside.
Flu vaccine can actually increase the risk of illness from influenza viruses. (Skowronski, PLoS Med 7(4):e1000258, 2010. Emborg, BMJ 344:d7901,2012. Cowling, CID 51:1370, 2010. Skowronski, CID 52:831, 2011. Crum-Cianfone, CID 49:1801, 2009. Iuliano, CID 49:1811, 2009. King, NEJM 355:2523, 2006. Thomas, Ped IDJ 22:201, 2003). There are at least three plausible mechanisms that explain why vaccination can increase risk: 1. It blocks the development of robust, complex and cross-protective immunity from active infection; 2. It commits the immune system to the vaccine strain and prevents an optimal response to a wild virus that may be only slightly different antigenically ("original antigenic sin").; 3. OAS is related to "antibody-dependent enhancement" whereby vaccine-induced antibody attaches to a wild virus but fails to neutralize it; instead the antibody actually fosters virus entry into cells and viral replication.
Flu vaccine also increases the risk of illness from other respiratory viruses. (Cowling, CID 54:1778, 2012. Kelly, PedIDJ 30:107, 2011). This may result from non-specific immune suppression or by aborting the "virus Interference" whereby cytokines evoked by one active infection repel subsequent invasion by other viruses.
One or more of the foregoing immune mechanisms may relate to recent observations that repeated vaccination progressively attenuates the modest protection sometimes afforded by seasonal flu vaccine. (Ohmit, CID 56:1363, 2013. Ohmit, CID 58:319, 2014. McLean CID online 9/29/14).
Rapid Response:
Mass flu vaccination is not only useless, as Margaret McCartney suggests; it may do real harm, opportunity cost aside.
Flu vaccine can actually increase the risk of illness from influenza viruses. (Skowronski, PLoS Med 7(4):e1000258, 2010. Emborg, BMJ 344:d7901,2012. Cowling, CID 51:1370, 2010. Skowronski, CID 52:831, 2011. Crum-Cianfone, CID 49:1801, 2009. Iuliano, CID 49:1811, 2009. King, NEJM 355:2523, 2006. Thomas, Ped IDJ 22:201, 2003). There are at least three plausible mechanisms that explain why vaccination can increase risk: 1. It blocks the development of robust, complex and cross-protective immunity from active infection; 2. It commits the immune system to the vaccine strain and prevents an optimal response to a wild virus that may be only slightly different antigenically ("original antigenic sin").; 3. OAS is related to "antibody-dependent enhancement" whereby vaccine-induced antibody attaches to a wild virus but fails to neutralize it; instead the antibody actually fosters virus entry into cells and viral replication.
Flu vaccine also increases the risk of illness from other respiratory viruses. (Cowling, CID 54:1778, 2012. Kelly, PedIDJ 30:107, 2011). This may result from non-specific immune suppression or by aborting the "virus Interference" whereby cytokines evoked by one active infection repel subsequent invasion by other viruses.
One or more of the foregoing immune mechanisms may relate to recent observations that repeated vaccination progressively attenuates the modest protection sometimes afforded by seasonal flu vaccine. (Ohmit, CID 56:1363, 2013. Ohmit, CID 58:319, 2014. McLean CID online 9/29/14).
Competing interests: No competing interests