A study published in Science journal on May 7th, expands our understanding that measles vaccines can protect against infection and mortality from other infectious diseases in addition to the measles virus itself.

Image/James Gathany
Image/James Gathany

Researchers led by Michael J. Mina at Princeton University conducted a retrospective study of deaths among children in the United States, the UK and Denmark to find that a correlation existed between incidence of measles and increased deaths from other infectious diseases, in periods before and after measles vaccines were available in these populations.

It has been recognized that measles virus has immunosuppressive effects by blocking differentiation of infected T-cells and B-cells, and can push the immune response away from protective cell-mediated immunity to a less-effective humoral response.

A previous study conducted by researchers de Vries and de Swart described the ‘measles paradox’ where for several weeks to months, after a general lymphocyte reduction from measles, the incipient immune cell response directed against the measles virus came at the expense of the re-establishment of immunity against other opportunistic infectious pathogens.

This study suggests that this ‘immunological amnesia’ appears to be sustained for up to 28 months.  The authors of this study conclude that measles vaccines confer an important ‘polymicrobial herd immunity’ when properly deployed.

Steven Smith, M.Sc. is an Infectious diseases epidemiologist