The U.S. Centers for Disease Control and Prevention (CDC) reported that the bivalent COVID-19 vaccine that is available today helps protect against infection by the omicron variant XBB and its subvariant XBB.1.5 that dominate infections today. The present bivalent booster was made specifically against both the initial SARS-CoV-2 virus and the BA.4/BA.5 variants. However, BA.5 and its subvariants account for just about two percent of cases now, and BA.4 and the original virus are essentially gone. The present bivalent booster is effective, even though it was not made from the viruses circulating today. The more boosters you have received, the higher the protection against infection.
• More than 55 million North Americans (20 percent) have received the latest bivalent booster, compared to close to 270 million who have received at least one dose of the original vaccine.
• The bivalent booster has been shown to reduce mild COVID-19 disease infection by more than 50 percent, and it reduces the death risk 13 times that of being unvaccinated.
• Protection against COVID-19 fades within about three months against XBB, faster than against other variants.
• The present bivalent BA.4–BA.5 vaccine produces higher neutralizing responses against all the viruses found today. Those who have had both an infection and the vaccination had the highest recorded neutralizing antibody titers, and those who had only the vaccination has significant rises in antibody titers (NEJM. Jan 26, 2023). The highest antibody titers were at four weeks and started to drop after that. Hospitalization after severe infection 15 to 99 days after receiving the bivalent vaccine was 35 percent lower than in those receiving the monovalent vaccine.
Dr. Gabe Mirkin is a Villager. Learn more at www.drmirkin.com