If you received the most recent bivalent CoVid booster, know that it does not induce significant or lasting antibody protection against the currently-prevalent Omicron XBB1.5 sub-variant. The good news: the booster does trigger an increase in your cellular immunity against the virus; and it reduces by half your risk of developing a symptomatic CoVid infection.

Researchers at Harvard’s Beth Israel Hospital now report their studies of thirty subjects tested for both humoral or antibody immunity and cellular immunity against a panel of CoVid variants and sub-variants before boosting, 3 weeks after, and 3 months after the boost. While the bivalent vaccine triggered a significant antibody rise against the BA.5 subvariant, the bump in protective antibody against XBB1.5 was

meager at best.

The response of CoVid-specific cellular immunity was another story. The vaccine booster triggered an impressive rise in both CD4+ and CD8+ T-cell responses against the virus.

To underscore the point that the booster is weakly protective against CoVid XBB1.5, 43% of the subjects developed a CoVid infection after receiving the booster.

Meanwhile, the CDC is out with the results of its own studies carried out over the past month as XBB1.5 is surging across the country. The bivalent booster effectiveness against so-called symptomatic CoVid was 49% for those 18-49 and 40-43% for those 50 and older. This protective effect appears to continue beyond 3 months after boosting.

The bottom line: the bivalent booster won’t prevent CoVid XBB1.5 from infecting you, but it will prevent that infection from sidelining and possibly killing you.

https://www.biorxiv.org/content/10.1101/2023.01.22.525079v1

https://www.cdc.gov/mmwr/volumes/72/wr/mm7205e1.htm?s_cid=mm7205e1_w#contribAff

#CoVid #xbb15 #booster #vaccine #antibody #cellularimmunity