Conjugate, Polysaccharide Vaccines Induce Mucosal Immunity.(Brief Article)

2001 SEP 5 - (NewsRx.com & NewsRx.net) --

by N.R. Saltmarsh, staff medical writer - Meningococcal A+C conjugate and polysaccharide vaccines induce significant mucosal responses in young adults, possibly even immunoglobulin (IgG) memory, according to a new report in Infection and Immunity.

"Meningococcal group A+C capsular polysaccharide (PS) conjugate vaccines may prime for serum immunoglobulin G (IgG) memory responses to meningococcal capsular PS," said Q. Zhang and colleagues working in England. "It is not known whether these vaccines induce immunological memory at the mucosal level, which may be important in reducing nasopharyngeal carriage."

Zhang and team studied mucosal immune responses to meningococcal conjugate and PS vaccines in healthy university students randomized to receive either a group A+C conjugate vaccine (MACconj, n=100) or a group A+C PS vaccine (MACPS, n=95).

One year after the primary immunization, both groups were randomized again to receive a MACconj or a MACPS booster, and saliva samples were collected before and one month after both the primary and booster vaccinations, reported Zhang and associates.

Measurement of anti-meningococcal A (MenA) and C (MenC) PS IgA and IgG antibody levels after the primary vaccination revealed that salivary MenA and MenC IgG and MenA IgA concentrations were significantly increased after immunization with both MACconj and MACPS vaccines, but the salivary Men C IgA level was increased only after MACPS vaccine, noted Zhang and coworkers. IgA responses to both serogroups were greater for MACPS than MACconj vaccine, but no significant differences were seen for IgG responses, they added.

"MenA IgG titers were higher after the MACPS booster in MACconj-primed subjects than after the MACPS primary vaccination, suggesting ...