This is a summary, written by members of the CITF Secretariat, of:

Cheung PK, Lapointe HR, Sang Y, Ennis S, Mwimanzi F, Speckmaier S, Barad E, Dong W, Liang R, Simons J, Lowe CF, Romney MG, Brumme CJ, Niikura M, Brockman MA, Brumme ZL. COVID-19 vaccine immunity study team. SARS-CoV-2 live virus neutralization after four COVID-19 vaccine doses in people with HIV receiving suppressive ART. AIDS. 2023 Feb 14. doi: 10.1097/QAD.0000000000003519.

The results and/or conclusions contained in the research do not necessarily reflect the views of all CITF members.

A CITF-funded study published in AIDS, demonstrated that fourth COVID-19 vaccine doses, irrespective of whether they are monovalent or bivalent, benefit people living with HIV (PLWH) who receive anti-retroviral therapies (ART), including those who have already experienced a SARS-CoV-2 infection. The study was a collaboration between Drs. Zabrina Brumme (BC Centre for Excellence in HIV/AIDS and Simon Fraser University) Mark Brockman (Simon Fraser University) and Marc Romney (University of British Columbia).

Key Findings:

  • In PLWH who did not previously experience COVID-19 (COVID-19-naïve), fourth doses improved neutralization of both the ancestral virus and Omicron BA.5 variant modestly above levels provided by three doses.
  • Among PLWH who previously had COVID-19, fourth doses improved neutralization of ancestral virus modestly, but neutralization of Omicron BA.5 was enhanced substantially above the three dose level.
  • Even after four doses, neutralization of Omicron variants was significantly poorer than neutralization of the ancestral SARS-CoV-2 strain;
    • On average, BA.5-specific neutralization was eight-fold lower compared with ancestral virus; and
    • On average, Omicron-BQ.1-specific neutralization was two-fold lower compared with Omicron-BA.5.
  • Nevertheless, post-forth dose, PLWH who previously experienced COVID-19 exhibited far stronger neutralization of all tested SARS-CoV-2 variants compared with those who were COVID-19 naïve, confirming that “hybrid” immunity (gained through a combination of vaccination and infection) is superior to that gained through vaccination alone.
  • For COVID-19-experienced PLWH, the infection strain did not influence the ability to neutralize Omicron variants after four vaccine doses. PLWH whose infection occurred during the Omicron era displayed comparable neutralization of BA.5 and BQ.1 compared to PLWH whose infection occurred prior to the emergence of Omicron.
  • A Moderna fourth dose (vs. Pfizer) was the strongest correlate of neutralization of the ancestral strain. In contrast, prior COVID-19 was the strongest correlate of neutralization of BA.5- and BQ.1. The valency of the fourth dose (monovalent vs. bivalent) did not influence neutralization magnitude.

In conclusion, fourth COVID-19 vaccine doses provide immune benefits to PLWH regardless of SARS-CoV-2 infection history. Results further support public health recommendations that all PLWH receive a fourth dose within six months of their third dose (or within six months of their most recent COVID-19 episode).

This study included 63 PLWH who completed their one-month post-fourth dose study visit as of December 2022. All PLWH had suppressed plasma HIV on ART. Fourth doses were received an average of 8.5 months after the third dose, and were either monovalent (44%) or bivalent (56%). 30% of participants remained COVID-19-naive, whereas 19% and 51% had experienced COVID-19 during the pre-Omicron and Omicron pandemic eras, respectively.