The Effects of Respiratory Vaccine Type and Timing on Antibody Titers, Immunoglobulins, and Growth Performance in Pre- and Post-Weaned Beef Calves

Round 1

Reviewer 1 Report

The paper is scientifically sound and interesting. The rationale for the comparison of the vaccine types and consideration of preweaning vs weaning vaccination and boosting is clearly brought out and justified, as well as the effect of maternal antibody interference on vaccinal responses. 

A few minor edits:

I suggest changing the last line of the abstract (lines 34/35) to "...may affect the onset of efficacious/robust vaccine responses."

Missing full stop in line 62 before "Killed viral vac-"

Line 177: 10⁴

Line 192: TMB substrate instead of The TMB substrate...

Minor Comments:

1. For the results summary (lines 218-219), please clarify what abnormal SN titer levels and why you think they would occur, and the rationale for omission (is this likely a technical issue unlikely to be a true occurrence, or does it just not fit with the rest of the data?)

2. Whilst no effect of vaccine type was observed with regard to BRSV titers and IgG isotype concentrations in serum, it may best to show the values for each treatment group separately in Figures 1 and 4, respectively. 

3. Looking at pathogen-specific (for instance BRSV and BVDV 1 and 2) IgG responses by ELISA may also be a clearer way to assess these responses relative to total IgG. Is there any reason that the latter was preferred? I however think this might not be a big concern as the animals are in a fairly well-controlled and uniform environment. 

Author Response

Thank you for your review. We have incorporated all suggestions into the revised document.

specific comments (Reviewer comments in Bold):

I suggest changing the last line of the abstract (lines 34/35) to "...may affect the onset of efficacious/robust vaccine responses." Change made as suggested

Missing full stop in line 62 before "Killed viral vac-" Change made as suggested

Line 177: 10⁴   Change made as suggested

Line 192: TMB substrate instead of The TMB substrate... Change made as suggested

Minor Comments:

1. For the results summary (lines 218-219), please clarify what abnormal SN titer levels and why you think they would occur, and the rationale for omission (is this likely a technical issue unlikely to be a true occurrence, or does it just not fit with the rest of the data?) This was not abnormal SN titer levels as indicated originally, it was unreadable samples for the assay. So, thus it was a technical issue and not a true occurrence. We restated the reason for removing the data from the analysis to "Finally, SN data from four calves were removed from the study 2 due to  missing data from inadequate serum volume and 2 due to unreadable samples." 

2. Whilst no effect of vaccine type was observed with regard to BRSV titers and IgG isotype concentrations in serum, it may best to show the values for each treatment group separately in Figures 1 and 4, respectively. Changes made to Figures 1 and 4 as suggested by reviewer.

3. Looking at pathogen-specific (for instance BRSV and BVDV 1 and 2) IgG responses by ELISA may also be a clearer way to assess these responses relative to total IgG. Is there any reason that the latter was preferred? I however think this might not be a big concern as the animals are in a fairly well-controlled and uniform environment. 

Total IgG and the subtypes IgG1 and IgG2 are not specific to the SN antibodies for BRSV and BVDV1 and BVDV2. it is simply a measure of total IgG antibodies which reflects the 2 subtypes. we included the IgG analysis to further elucidate the immune responses to our vaccine type and timing treatments beyond the SN BRSV and BVDV responses.

Reviewer 2 Report

The manuscript ‘The effects of respiratory vaccine type and timing on antibody titers, immunoglobulins, and growth performance in pre- and post-weaned beef calves’ evaluates three preconditioning vaccine protocols in beef cattle. Overall, the data presented are of interest to those in the field as preconditioning prepares calves for the vulnerable period of weaning.

Lines 133-137: When the calves were vaccinated, what was the protocol for running the calves through the chute for sample collection and vaccination? Were the calves run through the chute in a specific order based on vaccine protocol? Was there any concern about the transfer of any residual vaccine across the three regimens?

Table 1: 244 under KM needs to be aligned with the other numbers in the column.

Line 287: 14D PB needs to be defined in the text of the manuscript, it is only defined in the Figure 3 legend.

Figure 4a needs to be revised. It appears that the lines identifying significance across timepoints have shifted when the figure was uploaded.

Author Response

Thank you for your review of our manuscript.

We have made all suggested changes to the paper.

Specific comments to Reviewer (Reviewer comments in Bold):

Lines 133-137: When the calves were vaccinated, what was the protocol for running the calves through the chute for sample collection and vaccination? Were the calves run through the chute in a specific order based on vaccine protocol? Was there any concern about the transfer of any residual vaccine across the three regimens?

Calves were comingled across treatments on the two ranches before weaning and were comingled further after the fence-line weaning period during preconditioning. All treatments were represented on both ranches. Because they were in large groups there was no ordering of calves as they entered the working facility, but steps were taken to ensure there was no transfer of residual vaccine between calves. we added "At each ranch on D0, all calves were comingled and brought through the working facility in random order with no regard for treatment. All treatments were represented on both ranches of origin, and steps were taken to ensure no transfer of any residual vaccine across the three regimens by using separate needles and syringes for each vaccination treatment." to clarify this in the manuscript.

Table 1: 244 under KM needs to be aligned with the other numbers in the column.

Aligned as suggested

Line 287: 14D PB needs to be defined in the text of the manuscript, it is only defined in the Figure 3 legend.

defined in the text as suggested

Figure 4a needs to be revised. It appears that the lines identifying significance across timepoints have shifted when the figure was uploaded.

Figure 4 was reformatted as per suggestion by the other reviewer, we took care of this issue when the figure was changed.