Switch to Moderna booster after Pfizer shots better against omicron in 60+

At seven days after the booster, the heterologous-boosted participants had two-fold higher antibody levels than the homologous group and 60 percent higher levels at 28 days.Older heterologous-boosted participants also had higher levels of neutralizing antibodies against all of the SARS-CoV-2 variants tested—with the largest difference seen against omicron, which is notorious for thwarting vaccine-derived immune responses. At 28 days, the spread was 84 percent in the heterologous-boosted group to 73 percent in the homologous-boosted group.Overall, Young and co-authors concluded: "For the vulnerable older age group in particular, a heterologous booster COVID-19 vaccine regimen induces a higher anti-spike antibody titer and a stronger neutralizing antibody response against the highly infectious Omicron variant (~20 percent higher neutralization) than a homologous booster regimen."The trial is still ongoing, so the authors will continue to add participants and data.