Refining COVID-19 Vaccines and Implications for PLWH
By Jeffrey Laurence, M.D.
Booster doses are necessary to maintain an active state of immunity for all currently available COVID-19 vaccines This is particularly true for people living with HIV (PLWH). Vaccine efficacy is lower among the immune-suppressed, including PLWH, regardless of viral load or CD4 count. What is encouraging is that, compared to those who are vaccinated but not boosted, people who received boosters have dramatic reductions in COVID-19-related risk of death, regardless of HIV status. However, the coronavirus responsible for COVID-19 is continuously evolving. Defining the best parts of the virus to target for new vaccines and assessing responses in individuals recovering from current and pre-pandemic strains of the virus would be invaluable in designing future vaccine products.
amfAR Mathilde Krim fellow Dr. Aleksandar Antanasijevic was a member of a team that studied blood samples collected before the COVID pandemic, and from people recovering from COVID. Pre-pandemic samples commonly harbored antibodies against other coronaviruses linked to the common cold. Blood from people recovering from current pandemic strains of coronavirus had increases in antibodies to non-COVID-19 coronaviruses. The authors suggested two possible explanations, both of which suggest some similarities between common cold coronaviruses and the COVID coronavirus. There may have been a “back-boosting” of antibodies capable of neutralizing the pre-pandemic coronaviruses that people with COVID had previously recovered from, or COVID may have induced antibodies capable of cross-reacting with other coronaviruses. Evidence was found for both processes. Electron microscopes were then used to map the targets: specific regions of the viral envelopes eliciting such responses.
The authors concluded that the cross-boosting they identified “may have long-lasting implications for immunity to seasonal coronaviruses.” Their mapping studies in those recovering from COVID-19 could also assist in revising current vaccines.
amfAR was a funder of this research.
Dr. Laurence is amfAR’s senior scientific consultant.