VetMedPinkeye (infectious bovine keratoconjunctivitis) vaccination in beef cattle: does vaccination prevent IBK? — POSSIBLE (the treatment made no difference to IBK incidence)
In beef cattle, does vaccination against Moraxella bovis / Moraxella bovoculi prevent infectious bovine keratoconjunctivitis (pinkeye, IBK), or reduce its severity, compared with adjuvant alone, placebo or no vaccination?
Shelf #73 · gate-verified and displayed under the developer's blinded-trial rule
POSSIBLE (the treatment made no difference to IBK incidence): The null suffix is scoped to incidence — in the best trials, vaccination did not stop cattle getting pinkeye. In Angelos 2023, a randomized controlled blinded field trial in Northern California beef steers, the cumulative proportion of steers that developed IBK over 16 weeks did not differ between intranasal recombinant Moraxella bovis cytotoxin vaccine and adjuvant alone, although severity metrics were numerically lower in vaccinates and IBK-affected vaccinates had significantly fewer observation weeks with severe ulcers. In O'Connor 2019, a 2-year randomized blinded controlled trial of a conditionally licensed Moraxella bovoculi bacterin in Angus beef calves, vaccinated calves had numerically more IBK, not less (pooled risk ratio 1.30, 95% CI 0.84-2.01), and weaning weight did not differ (pooled difference -0.88 kg, 95% CI -7.2 to 5.43). The wider literature explains why older claims looked better: Burns & O'Connor 2008 found 123 vaccine-to-control comparisons from 38 studies (1960-2005), only 15 trials reporting randomization and blinding, and use of randomization and blinding was associated with decreased vaccine efficacy. So the honest shelf answer is: no shown protection against IBK incidence from either a modern recombinant M. bovis cytotoxin vaccine or a commercial M. bovoculi bacterin, with a single-trial severity signal (fewer weeks with severe ulcers) that is not an incidence benefit. Design class (a): a carded record (Angelos 2023; also O'Connor 2019 by its title and design) establishes both randomisation and blinding in its own record, and the incidence claim rests on those records. Drafted Nov 10, 2026 (VetMed build, topic #73); all figures from abstracts fetched and verified at drafting.
Angelos 2023: cumulative IBK incidence over 16 weeks did not differ between intranasal recombinant M. bovis cytotoxin vaccine and adjuvant alone in beef steers (the treatment made no difference to incidence); vaccinates had significantly fewer weeks with severe ulcers
Randomized controlled field trial (record's own wording: 'A randomized controlled field trial (two-arm parallel design with blinding)')
Who: Cattle (beef steers): beef steers in Northern California vaccinated intranasally on days 0 and 21 with either a recombinant Moraxella bovis cytotoxin subunit adjuvanted with polyacrylic acid (Vaccine group) or adjuvant alone (Control group); eye examinations on all steers every 7 days for 16 weeks to document IBK occurrence and corneal ulcer sizes, with serum and tear samples on days 0, 42 and 112 from a subset. The record's abstract does not state the number of steers enrolled.
Result: The cumulative proportion of steers that developed IBK after 16 weeks did not differ between groups (the record's abstract gives no incidence percentages). Variables related to disease severity were numerically lower in steers that received the experimental vaccine, and IBK-affected Vaccine group steers had a significantly lower number of observation weeks with severe ulcers versus Control group steers. Cytotoxin-specific tear IgA was significantly higher in the Vaccine group than the Control group on day 112. The authors conclude that although the proportion of animals that developed corneal ulcers associated with IBK did not differ between groups, the lowered metrics of disease severity suggest intranasal vaccination with recombinant M. bovis cytotoxin can reduce the severity of IBK in cattle.
Watch out: The incidence result is a null with no percentages in the abstract, so no absolute incidence rates can be quoted from this record, and the severity benefit rests on secondary metrics (weeks with severe ulcers significantly lower; other severity variables only numerically lower). The comparator is adjuvant alone, not an unvaccinated group. This record carries no MeSH terms in PubMed (see source line), so nothing about its indexing should be assumed beyond its stated design.
Angelos JA, Agulto RL, Mandzyuk B, Chigerwe M. Randomized controlled field trial to assess the efficacy of an intranasal Moraxella bovis cytotoxin vaccine against naturally occurring infectious bovine keratoconjunctivitis. Vaccine X. 2023;15:100378. PMID: 37693844. Registry ID: none in the record. MeSH: none in the record (no MeSH terms are listed for this record; its author keywords are Beef · Cattle · Infectious bovine keratoconjunctivitis · Intranasal · Moraxella bovis · Mucosal · Pinkeye · Polyacrylic acid · Vaccine)
O'Connor 2019: a conditionally licensed Moraxella bovoculi bacterin did not protect Angus beef calves against IBK over 2 years — vaccinated calves had numerically more IBK (pooled risk ratio 1.30, 95% CI 0.84-2.01)
Randomized blinded controlled trial (record's own title: 'A 2-year randomized blinded controlled trial'; abstract: 'A randomized controlled trial. The trial design was a 2-arm parallel trial with a 1:1 allocation ratio'; publication type: Randomized Controlled Trial, Veterinary)
Who: Cattle (beef calves): spring-born Angus calves at a university cow-calf herd; after excluding animals with ocular lesions, calves eligible for prevention assessment were 163 in 2017 (81 vaccinated, 82 unvaccinated) and 207 in 2018 (105 vaccinated, 102 unvaccinated), given 2 doses of the commercial M. bovoculi vaccine or no vaccine; 162 calves completed follow-up in 2017 and 206 in 2018.
Result: In both years, calves receiving the vaccine had more IBK; the effect was small. The pooled risk ratio was 1.30 (95% confidence interval 0.84-2.01) — a relative measure whose confidence interval includes both a 16% relative reduction and a doubling of risk, so it establishes no protection rather than proving harm. The pooled unadjusted difference in mean weight (kg) at weaning was -0.88 (95% confidence interval -7.2 to 5.43). The authors conclude they were unable to document that the M. bovoculi bacterin vaccine had a protective effect for the incidence of IBK in their single herd in a 2-year study.
Watch out: A different organism and product from Angelos 2023 (M. bovoculi bacterin, not recombinant M. bovis cytotoxin), a single university herd, and a confidence interval too wide to exclude a modest benefit or harm — the card supports 'no protection documented', not 'vaccination causes pinkeye'. Its comparator was unvaccinated calves, whereas Angelos used adjuvant alone.
O'Connor A, Cooper V, Censi L, Meyer E, Kneipp M, Dewell G. A 2-year randomized blinded controlled trial of a conditionally licensed Moraxella bovoculi vaccine to aid in prevention of infectious bovine keratoconjunctivitis in Angus beef calves. J Vet Intern Med. 2019;33(6):2786-2793. PMID: 31605550. Registry ID: none in the record. MeSH: Animals · Cattle · Bacterial Vaccines*/immunology · Cattle Diseases*/prevention & control · Keratoconjunctivitis*/microbiology, prevention & control, veterinary · Moraxella*/immunology · Moraxellaceae Infections*/microbiology, prevention & control, veterinary · Risk Factors
Burns & O'Connor 2008: across 123 vaccine-to-control comparisons from 38 studies (1960-2005), only 15 trials reported randomization and blinding — and using randomization and blinding was associated with decreased vaccine efficacy
Systematic review of methodological quality (record's own wording: 'A review was conducted of all identified literature evaluating Moraxella bovis vaccines efficacy in preventing pinkeye in beef calves'; publication type: Systematic Review)
Who: Cattle (beef calves): literature base of 292 publications identified, from which data on 123 unique vaccine-to-control comparisons were extracted from 38 studies published in English from 1960 to 2005 evaluating Moraxella bovis vaccines in young cattle.
Result: Descriptive analysis and an analysis of sources of variation found that use of methods to control bias such as randomization and blinding were associated with decreased vaccine efficacy. Only 15 trials reported using randomization and blinding. The authors conclude that when designing and reporting veterinary vaccination studies, researchers must include the methodological quality information necessary to judge the evidence produced.
Watch out: This is a methodological review, not an efficacy meta-analysis with a pooled protection estimate: it does not give a single vaccine-efficacy number, and its window (1960-2005) predates both carded trials above. Its role on this shelf is to explain why the older, less rigorous literature looked more favourable than the later blinded randomized trials.
Burns MJ, O'Connor AM. Assessment of methodological quality and sources of variation in the magnitude of vaccine efficacy: a systematic review of studies from 1960 to 2005 reporting immunization with Moraxella bovis vaccines in young cattle. Vaccine. 2008;26(2):144-52. PMID: 18054816. Registry ID: none in the record. MeSH: Animals · Bacterial Vaccines/immunology* · Cattle · Cattle Diseases/immunology, prevention & control* · Drug Evaluation/methods* · Moraxella bovis/immunology* · Moraxellaceae Infections/immunology, prevention & control, veterinary*
Synthesis: two randomized blinded trials found no protection against pinkeye incidence (one M. bovis cytotoxin vaccine, one M. bovoculi bacterin); the only positive signal is fewer weeks with severe ulcers in the cytotoxin trial, and the older literature's optimism tracks with weaker methods
Synthesis
Who: Synthesis of the cards above: Angelos 2023 (beef steers, Northern California, randomized controlled blinded field trial, intranasal recombinant M. bovis cytotoxin vs adjuvant alone, 16 weeks), O'Connor 2019 (Angus beef calves, 163 eligible in 2017 and 207 in 2018, 2-year randomized blinded controlled trial of M. bovoculi bacterin) and Burns & O'Connor 2008 (systematic review, 123 comparisons from 38 studies, 1960-2005).
Result: (1) Incidence: cumulative IBK over 16 weeks did not differ between vaccine and adjuvant alone (Angelos), and pooled IBK risk ratio for the M. bovoculi bacterin was 1.30 (95% CI 0.84-2.01) with no weaning-weight difference (-0.88 kg, 95% CI -7.2 to 5.43) (O'Connor). (2) Severity: IBK-affected vaccinates in Angelos had significantly fewer observation weeks with severe ulcers, with other severity variables numerically lower and tear cytotoxin-specific IgA significantly higher at day 112. (3) Methods: only 15 of the historical trials reported randomization and blinding, and those methods were associated with decreased measured vaccine efficacy (Burns & O'Connor).
Watch out: No carded record shows any IBK vaccine preventing pinkeye incidence in beef cattle, and Angelos's abstract reports no incidence percentages or enrolment number, so absolute effects cannot be stated. The severity signal comes from one trial's secondary metrics for one experimental vaccine; it should not be read as a class effect for commercial pinkeye vaccines, and O'Connor's wide confidence interval does not prove its bacterin is harmful.
Synthesis of Angelos JA et al. PMID: 37693844; O'Connor A et al. PMID: 31605550; Burns MJ, O'Connor AM. PMID: 18054816. Registry IDs as on the individual cards.
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