Increased detection of proliferating, polyfunctional, HIV-1-specific T cells in DNA-modified vaccinia virus Ankara-vaccinated human volunteers by cultured IFN-gamma ELISPOT assay.

Induction of a long-term immunological memory, which can expand and defend the host upon pathogen encounter, is the "holy grail" of vaccinology. Here, using a sensitive cultured IFN-gamma ELISPOT assay, we show that 50% (15 out of 30) of healthy, HIV-1/2-uninfected volunteers who received pTHr.HIVA DNA prime-modified vaccinia virus Ankara. HIVA boost vaccine regimen 1 to 3 1/2 years ago had detectable HIV-1-specific T-cell responses. These T cells, predominantly of the CD4(+) subtype, could proliferate and produce multiple cytokines in response to in vitro peptide stimulation. Peptide mapping studies showed that the vaccine-induced CD4(+) T cells were mostly directed toward epitopes targeted in HIV-1-infected individuals. In addition, we used the same assay to re-evaluate 51 volunteers from past vaccine trial IAVI-006 and corrected the previously reported 10% of vaccine responders to 50%. Thus, we confirmed that cultured assays are a valuable tool for studying T-cell memory. These results are discussed in the context of the current state-of-affairs of the HIV-1 vaccine field.

Attitudes to using the laryngeal mask airway in paediatric resuscitation.

AIM: To explore nurses' attitudes towards, and confidence in, the use of laryngeal mask airway (LMA) and oral Guedel airway (OGA). The research formed part of a larger study which examined whether nurses could deliver adequate ventilation in children using these two airways compared to a consultant anaesthetist. METHOD: Twenty five critical care nurses were trained to insert an LMA and an OGA. They were then required to insert each airway into an unconscious apnoeic child in the anaesthetic room. A questionnaire was devised to ascertain the participants' preferred airway and their attitudes towards using the airways at various times during the study period. FINDINGS: Before training the nurses were evenly divided about which airway they preferred but this changed to favouring the LMA after training. However, by the end of the study the majority of participants preferred to use the OGA. CONCLUSION: The nurses' confidence increased as a result of practising these ventilating techniques on patients. They felt that being able to insert an LMA as a second-line airway when the OGA was not providing adequate ventilation was useful. However, they also felt that they would need continuous training to update this skill.

Induction of multifunctional human immunodeficiency virus type 1 (HIV-1)-specific T cells capable of proliferation in healthy subjects by using a prime-boost regimen of DNA- and modified vaccinia virus Ankara-vectored vaccines expressing HIV-1 Gag coupled to CD8+ T-cell epitopes.

A double-blind randomized phase I trial was conducted in human immunodeficiency virus type 1 (HIV-1)-negative subjects receiving vaccines vectored by plasmid DNA and modified vaccinia virus Ankara (MVA) expressing HIV-1 p24/p17 gag linked to a string of CD8(+) T-cell epitopes. The trial had two groups. One group received either two doses of MVA.HIVA (2x MVA.HIVA) (n=8) or two doses of placebo (2x placebo) (n=4). The second group received 2x pTHr.HIVA followed by one dose of MVA.HIVA (n=8) or 3x placebo (n=4). In the pTHr.HIVA-MVA.HIVA group, HIV-1-specific T-cell responses peaked 1 week after MVA.HIVA vaccination in both ex vivo gamma interferon (IFN-gamma) ELISPOT (group mean, 210 spot-forming cells/10(6) cells) and proliferation (group mean stimulation index, 37), with assays detecting positive responses in four out of eight and five out of eight subjects, respectively. No HIV-1-specific T-cell responses were detected in either assay in the 2x MVA.HIVA group or subjects receiving placebo. Using a highly sensitive and reproducible cultured IFN-gamma ELISPOT assay, positive responses mainly mediated by CD4(+) T cells were detected in eight out of eight vaccinees in the pTHr.HIVA-MVA.HIVA group and four out of eight vaccinees in the 2x MVA.HIVA group. Importantly, no false-positive responses were detected in the eight subjects receiving placebo. Of the 12 responders, 11 developed responses to previously identified immunodominant CD4(+) T-cell epitopes, with 6 volunteers having responses to more than one epitope. Five out of 12 responders also developed CD8(+) T-cell responses to the epitope string. Induced T cells produced a variety of anti-viral cytokines, including tumor necrosis factor alpha and macrophage inflammatory protein 1 beta. These data demonstrate that prime-boost vaccination with recombinant DNA and MVA vectors can induce multifunctional HIV-1-specific T cells in the majority of vaccinees.