They show that combining vaccines improves immunity against HIV

They show that combining vaccines improves immunity against HIV

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A team from CSIC National Center for Biotechnology (CNB-CSIC), together with an international consortium, has shown that combination of vaccines and the period of administration are decisive for achieving early and memory immune responses against the HIV virus. The results of the study have been published in the journal Frontiers in Immunology.

This study in Rhesus macaques demonstrates the importance of the combination of vaccines and administration times to achieve better immune responses against HIV

Mariano Esteban, CNB-CSIC

“This study in Rhesus macaques demonstrates the importance of the combination of vaccines and administration times to achieve better immune responses against HIV”, explains the virologist Mariano Esteban, co-author of the work. “This result is applicable to other vaccines,” he adds.

To control HIV infection, a powerful immune response sustained over time is required, with the generation of neutralizing antibodies with a broad spectrum of action, and the activation of memory B and T lymphocytes (white blood cells) specific against the virus.

Combining vaccines improves immunity against HIV. | Photo: Mufid Majnun | unsplash

International efforts to curb AIDS

Due to the importance of this infection and the disease it causes, AIDS, it is essential to develop an effective vaccine against this pathogen, which causes 700,000 annual deaths on a planetary scale.

“In this international project, we have characterized the effect of combining three types of vaccines in macaques: one based on nucleic acid (DNA), another on a non-replicative poxvirus vector in human cells (NYVAC) and a third on the Env protein of the HIV envelope together with an adjuvant”, Esteban enumerates.

The main questions that have been raised by the researchers have been, on the one hand, if the co-administration of the Env protein together with the DNA or NYVAC vaccine can accelerate the antibody induction and, on the other, if it is possible to improve the quality of immune responses correlated with protection by adding late booster doses.

Different vaccines and administration periods

Different combinations of DNA, the NYVAC vector and the Env protein were administered intramuscularly to Rhesus macaques divided into groups of 8 to 12 animals. These primates were inoculated at 0, 4, 12 and 24 weeks and the effect of re-immunization at 36 and 48 weeks was studied to see if it improved their immune response.

Beatrice Perdiguero, first author of the research, indicates that “the different regimens induced broad, polyfunctional and balanced immune responses in terms of the activation of CD4 and CD8 T cells. Likewise, there was also a high production in plasma of antibodies binding to the V1/V2 domains of the Env protein and another, more modest, of antibodies dependent on cytotoxic cells (ADCC) and neutralizing antibodies».

These markers Immune systems are considered essential to achieve control of HIV infection. The authors conclude that the use of the Env protein as the first dose of vaccination administered together with DNA or with the NYVAC vector represents a optimized immunization protocol against HIV.

These studies are important in the development of vaccination strategies against HIV by enhancing the different components of the immune system that can control the resistance of the virus to the action of vaccines

Mariano Esteban, CNB-CSIC

“These studies are important in the development of vaccination strategies against HIV by enhancing the different components of the immune system that can control the resistance of the virus to the action of the vaccines,” says Esteban.

In addition, adds the researcher, “they provide information on how the continued administration of vaccines does not exponentially increase the immune response induced beyond the fourth dose, which may be applicable to the effect that the increase in the booster dose may have against the coronavirus”.

Reference

Beatriz Perdiguero, Mariano Estebán et al. “Early and long-term HIV-1 immunogenicity induced in macaques by the combined administration of DNA, NYVAC and Env protein-based vaccine candidates: The AUP512 Study”. Frontiers in Immunology (2022)

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