What is Hacking’s argument for entity realism?

According to Ian Hacking’s Entity Realism, unobservable entities that scientists carefully manipulate to study other phenomena are real. Although Hacking presents his case in an intuitive, attractive, and persuasive way, his argument remains elusive. I present five possible readings of Hacking’s argument: a no-miracle argument, an indispensability argument, a transcendental argument, a Vichian argument, and a non-argument. I elucidate Hacking’s argument according to each reading, and review their strengths, their weaknesses, and their compatibility with each othe

Association between anti-HLA reactivity following vaccination with formalin-inactivated SIV and outcome of challenge.

<p>Virus infection status was determined by PCR for SIV<i>gag</i> proviral DNA and virus isolation (VI) from PBMC of macaques challenged with SIVmac₂₅₁32H (a) following vaccination with inactivated SIV with either 3×500 µg doses (group A) or 4×100 µg doses (group B). Bar charts show the associated median fluorescence intensity (y axis) of serum samples for each macaque tested against HLA class I (red bars) and class II (green bars) bead sets (x axis). Background binding of pre-vaccination sera is shown as light red and light green for HLA class I and class II respectively. * indicates not tested, probe number refers HLA allele-specific bead sets.</p

Association between anti-HLA reactivity following vaccination with fixed-inactivated SIV infected and uninfected C8166 cells and outcome of challenge.

<p>Virus infection status was determined by PCR for SIV<i>gag</i> proviral DNA and virus isolation (VI) from PBMC of macaques challenged with SIVmac₂₅₁32H (a) following vaccination with 2 doses of SIV infected C8166 cells (group C) or with uninfected C8166 cells (group D). Bar charts show the associated median fluorescence intensity (y axis) of serum samples for each macaque tested against HLA class I (red bars) and class II (green bars) bead sets (x axis). Background binding of pre-vaccination sera is shown as light red and light green for HLA class I and class II respectively. * indicates not tested, probe number refers HLA allele-specific bead sets.</p

Infectivity neutralising activity against virus unrelated to vaccine.

<p>Neutralising antibody activity against SIVsmE660 propagated on human C8166 cells in sera from macaques immunised with uninfected C8166 cell vaccines (group E) in the absence (left panel) or presence (right panel) of complement. Pre-immune sera (black line) shows means of all animals with standard deviations. Dashed lines indicate unprotected animal.</p

Association between anti-HLA reactivity following vaccination with uninfected C8166 cells using different adjuvants and outcome of challenge.

<p>Virus infection status was determined by PCR for SIV<i>gag</i> proviral DNA and virus isolation (VI) from PBMC of macaques challenged with SIVmac₂₅₁32H (a) following vaccination with 4 doses of uninfected C8166 cells with Quil A adjuvant (group E) or with GMDP adjuvant (group F) (a) following vaccination with 2 doses of SIV infected C8166 cells (group C) or with uninfected C8166 cells (group D). Bar charts show the associated median fluorescence intensity (y axis) of serum samples for each macaque tested against HLA class I (red bars) and class II (green bars) bead sets (x axis). Background binding of pre-vaccination sera is shown as light red and light green for HLA class I and class II respectively. * indicates not tested, probe number refers HLA allele-specific bead sets.</p

Infectivity neutralising activity against virus propagated on discordant cell substrate.

<p>Neutralising antibody activity against SHIV_W61D propagated on either human C8166 cells (solid lines) or macaque HSC-F cells (dotted lines) in sera from macaques immunised with SIV-infected (J69; green lines) or uninfected C8166 cell (J73; purple lines) vaccines.</p

Rectal Administration of Tenofovir Gel Protected a High Proportion of Macaques against Subsequent Acquisition of SIV by Rectal Transmission

<p>The results of VI from PBMC are shown as + or − for each animal. The temporal profiles of plasma vRNA concentration (red dot) and frequency of PMBC-associated proviral DNA (blue triangle) are shown for each animal in the study.</p

SIV-Specific IFN-γ Secreting T Cells Were Detected in SIV-Challenged Macaques in the Absence of Serum Antibody Responses and Evidence of Overt Infection

<div><p>(A) IFN-γ secreting T cell frequencies in PBMC from protected animals (D68–D14) compared to those in an SIV-infected animal (E81) measured 20 wk after virus exposure measured by ex vivo ELISpot. The mean frequencies of three replicate determinations plus one standard deviation are shown for each peptide pool used.</p> <p>(B) SIV-specific IFN-γ secreting T cell frequencies in MNC isolated from ileum–jejunum tissue of four protected animals measured post mortem at 21 wk after virus challenge by ex vivo ELISpot.</p> <p>(C) The group mean +/− standard deviation profile of anti-SIV Gag p27 binding antibody titres (measured by ELISA) from animals infected with SIV (○) and the individual profile for an SIV-infected macaque E81 (○), in which T cell ELISpot was analysed was compared with animals from which no virus was detected following challenge (▴). </p></div

Colorectal Explants from Macaques Supported Replication of SIV That Was Inhibited by Pretreatment with Tenofovir In Vitro and In Vivo

<div><p>(A) Replication dynamics of SIVmac_251/32H in explants from two untreated animals (group F: M3, M6) in the presence or absence of exogenously added tenofovir at 100 μg/ml. A total of 10⁴ TCID₅₀ of virus was added to each well containing three explants in a total volume of 200 μl of medium. Virus replication was assayed by SIV Gag p27 production and mean values +/− standard deviations are shown for four replicates of each tissue.</p> <p>(B) Colorectal explants from four animals (group G: M1, M38, M5, M32) dosed in vivo with tenofovir per rectum 3 h before tissue removal were exposed to virus in vitro (as described above) and culture supernatants assayed for Gag p27. Mean percent inhibition of SIV Gag p27 production plus standard deviations are shown.</p></div

Solution and Gel Formulated Tenofovir Inhibited SIV_mac251/32H Infectivity In Vitro at Similar Doses and in the Same Range as for Representative HIV-1 Isolates

<p>Infection of TZM-bl indicator cells in the presence and absence of tenofovir was compared by luminescence analysis of cell lysates and the results expressed as percent inhibition. The graph shows the full titration of drug formulations on infection with SIV_mac251/32H; the virus stock used in subsequent challenge experiments in vivo. Each point represents the mean of three independent experiments performed in triplicate +/− standard deviation. The results for a panel of HIV-1 strains in comparison to SIV_mac251/32H are shown as IC₅₀ values in the inset.</p