B-Enhancement of HBV Vaccination in Persons Living With HIV (BEe-HIVe): Evaluation of HEPLISAV-B: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for B-Enhancement of HBV Vaccination in Persons Living With HIV (BEe-HIVe): Evaluation of HEPLISAV-B (NCT04193189), a randomized phase 3 study. The primary outcome is Percentage of Participants With Primary Seroprotection Response.

2. Clinical Question

The trial asked whether people living with HIV would meet a defined antibody-response threshold after hepatitis B vaccination, and how response percentages differed among the vaccine schedules studied. Its primary endpoint was seroprotection response: an anti-HBs titer of at least 10 mIU/mL, measured at a specified interval after the vaccination series.

The study also recorded secondary outcomes concerning seroprotection, anti-HBs titer categories, and grade 2 or higher adverse events after vaccination. These are distinct questions: the primary endpoint concerns a defined antibody threshold, while the other outcomes describe additional antibody and safety measures.

3. Trial Design

This was a completed phase 3 randomized, parallel-group trial with no masking. The registry record lists enrollment of 638 participants and a study period beginning 2020-12-14, with primary completion on 2024-08-13. The sponsor was the National Institute of Allergy and Infectious Diseases (NIAID).

The trial addressed two study populations separately. Group A consisted of people living with HIV who had previously received hepatitis B vaccine and were deemed non-responders. Group B consisted of people living with HIV who were naïve to hepatitis B vaccination. The registry description says the study and its analyses were conducted separately for these populations.

Group A had three study arms. One received two HEPLISAV-B injections at Weeks 0 and 4. Another received three HEPLISAV-B injections at Weeks 0, 4, and 24. The third received three ENGERIX-B injections at Weeks 0, 4, and 24. Group B received three HEPLISAV-B injections at Weeks 0, 4, and 24. The registry describes HEPLISAV-B as a hepatitis B vaccine with a cytosine phosphoguanine adjuvant and ENGERIX-B as a conventional hepatitis B vaccine with an aluminum hydroxide adjuvant.

The primary endpoint timing differed by schedule: Week 12 for Group A’s two-injection arm, and Week 28 for Group A’s three-injection arms and Group B. The primary endpoint population was restricted to eligible participants who initiated the vaccination series and had anti-HBs data at the relevant time. The registry record does not report the original sample-size justification or the trial’s original design assumptions. Allocation concealment details are not reported in the registry record.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Eligible participants who initiated study vaccination series and had anti-HBs data available at the specified time point

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

Population: Eligible participants who initiated study vaccination series.

6. Primary Endpoint

The registry lists the primary outcome as Percentage of Participants With Primary Seroprotection Response, measured over Week 12 in Group A 2-CpG, Week 28 in Group A 3-CpG and 3-alum and in Group B.

The primary endpoint was the percentage of participants with a primary seroprotection response. A response meant an anti-HBs antibody titer of at least 10 mIU/mL at 8 weeks after completion of the two-dose series or at 4 weeks after completion of a three-dose series. The scheduled assessment was Week 12 for the two-injection Group A arm and Week 28 for the three-injection arms and Group B.

The registry description allowed a delay of no more than 4 weeks in completing the vaccine series. If a series was delayed, the protocol specified using an antibody result collected 8 weeks after completion of the two-dose series or 4 weeks after completion of the three-dose series for the primary endpoint analysis. Thus, the endpoint was tied to time since completion, with the stated calendar-week assessments reflecting the planned schedules.

A threshold endpoint translates an antibody measurement into the proportion of participants who did or did not meet a defined criterion. It is used to report how commonly the specified response occurred in each study arm. As a general statistical point, this binary summary is straightforward to compare across arms, but it does not convey the full spread of antibody titers or how long a response persists. The posted primary endpoint is an antibody response measure; it is not itself a measure of hepatitis B infection or clinical disease.

The registry record defines the analysis population as eligible participants who initiated vaccination and had anti-HBs data at the specified time point. The reasons that some participants might not have contributed endpoint data are not reported in the registry record.

7. Results Posted in the Registry

• Group A: 3-CpG: 99.4% (168/169) versus 93.1% (162/174) on control; risk difference 6.3 percentage points (95% CI 2.4 to 10.2), risk ratio 1.07 (1.02–1.11); unadjusted two-proportion z-test p = 0.002.
• Group A: 3-alum: 80.6% (133/165) versus 93.1% (162/174) on control; risk difference -12.5 percentage points (95% CI -19.6 to -5.4), risk ratio 0.87 (0.80–0.94); unadjusted two-proportion z-test p = <0.001.
• Group B: 100.0% (68/68) versus 93.1% (162/174) on control; risk difference 6.9 percentage points (95% CI 3.1 to 10.7), risk ratio 1.07 (1.03–1.12); unadjusted two-proportion z-test p = 0.026.

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is binary for each participant: the anti-HBs titer either meets the threshold of at least 10 mIU/mL or does not. The arm-level result is expressed as a percentage of participants meeting that definition. In general, a percentage provides an intuitive description of response frequency, while a comparison between percentages describes how the response frequency differs between arms.

How to read a risk difference

A risk difference is the response proportion in one group minus the response proportion in the reference group. A positive value means the first group has a higher observed response proportion; a negative value means it has a lower observed response proportion. The recalculated comparisons use the two-injection HEPLISAV-B arm as the reference. Their estimates are expressed as proportions: 0.063 for three-injection HEPLISAV-B, -0.125 for ENGERIX-B, and 0.069 for Group B. The Group B contrast is a cross-population comparison and should not be treated as if it were a randomized comparison within Group A.

A confidence interval gives a range of values compatible with the data and the method used, subject to the method’s assumptions. It reflects uncertainty in an estimate; it is not a range containing a known fixed percentage of individual participants. For the Group A sponsor comparisons, the registry specifies two-sided 97.5% confidence intervals. For Group B, it specifies a two-sided 95% Wilson interval around the single-arm estimate. The confidence level for the simple recalculated intervals is not stated in the comparison details, so those limits are best read as the posted recalculation’s interval limits rather than assigned an unstated level.

What the reported analysis labels mean

The registry labels one Group A comparison as non-inferiority and two as superiority. In general, a non-inferiority analysis asks whether an intervention is not unacceptably worse than a comparator according to a prespecified margin. A superiority analysis evaluates whether the data support a difference in a specified direction under its statistical framework. The non-inferiority margin and the detailed testing procedures are not reported in the registry record. Therefore, the labels can be stated, but the margin or full decision rule cannot be reconstructed from the posted analysis results alone.

The sponsor reports common proportion differences for Group A. Those estimates are 12.5 for two-injection HEPLISAV-B versus ENGERIX-B, 18.4 for three-injection HEPLISAV-B versus ENGERIX-B, and 6.0 for two-injection versus three-injection HEPLISAV-B. The reported confidence intervals are on the same percentage-difference scale. By contrast, the recalculated risk differences are simple unadjusted calculations from the posted arm summaries and are expressed as proportions. The methods and scales differ, so the two sets of estimates should not be treated as interchangeable.

Why an unadjusted p-value is limited

A p-value describes how unusual data at least as incompatible with a specified null hypothesis would be if that null hypothesis and the analysis assumptions were true. It is not the probability that the null hypothesis is true, nor does it measure the size or practical importance of an effect. The recalculated p-values are explicitly unadjusted. The registry record lists 14 analyses across 7 outcome measures, but does not report a multiplicity adjustment for the recalculated comparisons. When several comparisons or outcomes are considered, repeated testing can increase the chance of at least one apparently notable result. The registry record does not state how this issue was handled across all analyses.

The trial description says that Group A and Group B were analyzed separately as prespecified in the study protocol and Statistical Analysis Plan. It also specifies different interval approaches for Group A comparisons and the Group B single-arm estimate. The full protocol and Statistical Analysis Plan details, including the exact statistical methods used for the reported sponsor analyses, are not reported in the registry record.

Over-dispersion and model choice

Over-dispersion is a general concern when observed variability is greater than a statistical model expects. It can make standard errors too small and intervals too narrow if a model does not accommodate the extra variability. The primary outcome is a participant-level binary response, and the posted summaries do not report a dispersion estimate or a model-based adjustment for over-dispersion. It would therefore be inappropriate to claim that over-dispersion was present or that a particular correction was used. The registry record does not report the detailed modeling choices for the sponsor analyses.

The recalculated comparisons are simple, unadjusted re-calculations from posted summary statistics. They do not replace the sponsor’s own analysis framework or account for unreported covariates, stratification, or other analysis features. Whether any such features were part of the sponsor’s analysis is not reported in the registry record.

10. Confidence Intervals and Precision

The arm percentages are point estimates, and their precision depends partly on the number of participants contributing endpoint data and on the observed response frequency. The primary endpoint denominators were 174 for Group A’s two-injection HEPLISAV-B arm, 169 for Group A’s three-injection HEPLISAV-B arm, 165 for Group A’s ENGERIX-B arm, and 68 for Group B. These denominators are smaller than the trial’s enrollment of 638 because the endpoint population was defined by eligibility, initiation of vaccination, and availability of anti-HBs data at the specified time.

The sponsor’s Group A comparisons use two-sided 97.5% confidence intervals. The reported interval for two-injection HEPLISAV-B versus ENGERIX-B is 4.1 to 20.9; for three-injection HEPLISAV-B versus ENGERIX-B it is 10.4 to 26.2; and for two-injection versus three-injection HEPLISAV-B it is -0.2 to 11.8. The last interval extends across zero, so its reported estimate is compatible with values on either side of zero under that interval procedure. The registry’s label for that analysis is “superiority,” but the registry record does not provide a p-value or the full decision rule for interpreting it.

For Group B, the single-arm estimate is 100.0%, with a two-sided 95% Wilson confidence interval from 94.7% to 100.0%. A 100.0% observed percentage does not imply that the underlying response probability is known without uncertainty; the interval communicates that uncertainty. The interval is bounded by the natural upper limit of a percentage.

In general, confidence intervals are more informative than point estimates alone because they show the range of estimates reasonably compatible with the data and method. They do not address every source of uncertainty, such as missing endpoint data, analysis choices, or generalizability to populations outside the trial. The registry record does not report the reasons for unavailable endpoint measurements or all details needed to assess those sources of uncertainty.

11. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The planning figures are illustrations based on the observed effect, not the trial’s original sample-size justification. For the binary outcome, each planning entry gives participants per arm, rather than total events. The stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The effect used for each scenario is the stated fraction of the observed effect. The trial’s own original design assumptions are not reported in the registry record.

The 80% power column describes the number of participants per arm that the illustration estimates would be needed for an 80% chance of detecting the specified effect under its assumptions, if that effect and the assumptions were correct. The 90% power column gives the corresponding planning figure for a 90% chance. These are planning concepts, not guarantees about a future study or explanations of the trial’s achieved results.

For example, the entries for the three-injection versus two-injection HEPLISAV-B comparison are 142 participants per arm for 80% power and 189 participants per arm for 90% power when planning for 100% of the observed effect. Planning for 75% of the observed effect gives 303 participants per arm for 80% power and 405 for 90% power. Planning for 50% of the observed effect gives 795 per arm for 80% power and 1,064 for 90% power. The other comparison-specific entries likewise increase as the effect being planned for becomes smaller.

In general, smaller effects are harder to distinguish from random variation, so they require more participants under otherwise unchanged assumptions. These figures are not observed power: they are planning illustrations calculated from the observed effect, not a measure of the probability that the completed trial detected a true effect.

12. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, p₀ and p₁ are the control and treatment proportions, and p̄ is their average.

Worked calculation for this trial

1. Control proportion p₀ = 0.931; treatment proportion p₁ = 0.994; average p̄ = 0.963.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.2685 = 0.5262.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.2647 = 0.2228.
4. n = (0.5262 + 0.2228)² / (0.0630)² = 141.1, rounded up to 142 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
p0 <- 0.931034482758621                          # control proportion
p1 <- 0.994082840236686                          # treatment proportion
n_per_arm <- function(power, frac = 1) {
  q1 <- p0 + (p1 - p0) * frac               # smaller effect = fraction of the observed difference
  pbar <- (p0 + q1) / 2
  z_b <- qnorm(power)
  ceiling(round((z_a * sqrt(2 * pbar * (1 - pbar)) + z_b * sqrt(p0 * (1 - p0) + q1 * (1 - q1)))^2 / (q1 - p0)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (unrounded n per arm)
cat("power.prop.test:", round(power.prop.test(p1 = p0, p2 = p1, power = 0.80)$n, 1), "\n")

# Simulation: how often does the z-test reject at the 80%-power sample size?
set.seed(4193189)
n    <- n_per_arm(0.80)
reps <- 20000
x0 <- rbinom(reps, n, p0); x1 <- rbinom(reps, n, p1)
ph <- (x0 + x1) / (2 * n)
z  <- ((x1 - x0) / n) / sqrt(ph * (1 - ph) * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(z) > z_a, na.rm = TRUE), reps))

Output from running the code

100% of observed effect: n per arm = 142 (80% power), 189 (90% power)
 75% of observed effect: n per arm = 303 (80% power), 405 (90% power)
 50% of observed effect: n per arm = 795 (80% power), 1,064 (90% power)
power.prop.test: 141.1 
Simulated power at n = 142 per arm: 0.869 (20000 replicates)

The simulation draws many pairs of event counts at the planned sample size and counts how often the two-proportion z-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

13. Analyses Reported by the Sponsor

The registry reports the sponsor’s own Group A analyses as common proportion differences with two-sided 97.5% confidence intervals. The two-injection HEPLISAV-B versus ENGERIX-B estimate is 12.5, with an interval from 4.1 to 20.9, and is labelled as non-inferiority. The three-injection HEPLISAV-B versus ENGERIX-B estimate is 18.4, with an interval from 10.4 to 26.2, and is labelled as superiority. The comparison of the two HEPLISAV-B schedules is 6.0, with an interval from -0.2 to 11.8, and is labelled as superiority. The registry record lists no p-value for these analyses.

The recalculated estimates are unadjusted risk differences derived directly from the posted arm summaries. Their scale and calculation may differ from the sponsor’s common proportion difference analysis. They are useful as a transparent summary calculation, but they are not a substitute for the sponsor’s prespecified analysis. No discrepancy between the posted sponsor results and the recalculation is flagged in the record. The non-inferiority margin and full statistical procedures are not reported in the registry record, so the sponsor’s labels cannot be independently reconstructed from the reported numbers alone.

14. Multiplicity, Missing Data and Analysis Populations

The registry record states that the two study populations were designed and analyzed separately, as prespecified in the protocol and Statistical Analysis Plan. It specifies two-sided 97.5% confidence intervals for Group A differences and a two-sided 95% Wilson confidence interval around Group B’s single-arm estimate. It also lists 7 outcome measures and 14 analyses. The record does not report a complete multiplicity strategy describing how the family of outcomes and comparisons was handled.

Multiplicity matters because assessing several outcomes or comparisons can raise the chance that at least one result appears notable by chance. In general, a prespecified adjustment or testing hierarchy can address that issue, but the registry record does not describe whether or how such an approach was used across all analyses. The simple recalculated p-values are unadjusted and should be understood in that context.

The registry identifies the primary endpoint population as eligible participants who initiated the vaccination series and had anti-HBs data available at the specified time point. The endpoint denominators are 174, 169, 165, and 68 across the four arms. The registry record does not report why some enrolled participants are not represented in those denominators, the extent or handling of missing endpoint data, or whether imputation or sensitivity analyses were used.

The available description therefore distinguishes the primary endpoint analysis population, but it does not establish that every analysis used the same population or explain how missingness was handled for each outcome. The protocol and Statistical Analysis Plan are mentioned, but their detailed analysis-population definitions and missing-data procedures are not reported in the registry record. Interim analyses and any associated decision procedures are also not reported in the registry record.

15. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: appendicitis (1.4%), postoperative ileus (1.4%), prostate cancer (1.4%), depression (1.4%), suicidal ideation (1.4%).

The registry reports serious adverse event counts and the numbers at risk for each study group. Group A’s two-injection HEPLISAV-B arm had 12 participants with serious adverse events among 187 at risk; the three-injection HEPLISAV-B arm had 15 among 188; and the ENGERIX-B arm had 11 among 186. Group B had 4 among 74. These are reported counts, not percentages calculated.

The record also lists other adverse events: 133 participants among 187 at risk in the two-injection arm, 146 among 188 in the three-injection HEPLISAV-B arm, 134 among 186 in the ENGERIX-B arm, and 64 among 74 in Group B. Death counts were 1, 1, 0, and 0, respectively. The record lists Appendicitis, Postoperative ileus, Prostate cancer, Depression, Suicidal ideation, and Suicide attempt as serious adverse event terms, each at 1.4%.

These figures describe reported events and group-level counts. They do not, by themselves, establish that an event was caused by a vaccine or indicate comparative risk. The registry record does not report attribution, event timing, or the follow-up period for these safety counts. Group B is also a distinct population, so its count should not be interpreted as a direct randomized safety comparison with Group A.

16. What the Result Does, and Does Not, Mean

The posted results show that the observed percentage meeting the primary antibody-response definition was 93.1% in Group A’s two-injection HEPLISAV-B arm, 99.4% in the three-injection HEPLISAV-B arm, and 80.6% in the ENGERIX-B arm. Group B’s single-arm estimate was 100.0%. The sponsor’s reported comparisons and the simple unadjusted recalculations describe differences in these endpoint response proportions, with uncertainty summarized by their respective intervals.

These findings concern a defined anti-HBs threshold at specified times after vaccination. They do not establish how long antibody levels remained above the threshold, whether participants avoided hepatitis B infection, or how vaccination affected clinical disease. Those outcomes are not reported in the registry record. An antibody endpoint should not be treated as interchangeable with a clinical outcome.

The comparison of Group B with a Group A arm also requires care. Group B consisted of people naïve to hepatitis B vaccination, while Group A consisted of prior vaccine recipients deemed non-responders. The groups therefore represent different study populations, and the registry describes their analyses separately. The Group B response percentage is not a randomized contrast within Group A.

The trial was randomized and unmasked. Randomization supports comparisons among randomized arms, but the absence of masking remains relevant when interpreting outcomes that could be influenced by knowledge of treatment assignment. The primary endpoint is an antibody measurement, but the registry record does not report laboratory blinding or other details that would clarify this issue.

Finally, the safety counts are descriptive. They do not establish causation, and the record does not provide the timing or attribution needed to connect individual events to a study vaccine. Overall, the results describe the posted endpoint estimates and their precision; they do not support conclusions beyond the measured antibody response and reported safety events.

17. Why This Trial Matters Statistically

This trial illustrates why clinical trial results need to be read at the level of both population and endpoint. The study included two different groups of people living with HIV: prior hepatitis B vaccine recipients deemed non-responders and people naïve to vaccination. Keeping those populations distinct is important because their starting histories differ, and the registry says they were analyzed separately.

It also demonstrates how a clear binary definition can make an immune response interpretable: participants either met the anti-HBs threshold of at least 10 mIU/mL at the specified time or did not. Reporting the response percentage alongside the denominator and interval helps distinguish a high point estimate from a precisely known response probability. Group B’s 100.0% observed estimate, for example, still has a reported interval from 94.7% to 100.0%.

The record provides both sponsor analyses and simple unadjusted recalculations. Reading them side by side highlights that an effect estimate depends on the analysis method and scale, and that a recalculation from summary statistics is not the same as the sponsor’s reported framework. The registry’s non-inferiority and superiority labels also show why interpretation depends on design details such as a non-inferiority margin, which is not reported in the registry record.

Finally, the study underscores that antibody response, safety event counts, and clinical protection are separate statistical questions. The posted data address the first two at specified time points and with the reported definitions. They do not report long-term antibody persistence or clinical hepatitis B outcomes.

18. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
• Participant counts were reconstructed from posted percentages and arm sizes, so small rounding differences are possible.

Several features of this specific record constrain interpretation. First, the trial was unmasked. The registry does not report whether laboratory personnel assessing anti-HBs were masked to assignment, so the record does not resolve whether outcome assessment was shielded from knowledge of the assigned vaccine schedule.

Second, the primary assessment timing differed by schedule: Week 12 for the two-injection Group A arm and Week 28 for the three-injection arms and Group B. The endpoint definition also anchors measurement to completion if a series was delayed. These details are specified, but the registry record does not provide the individual timing of measurements or the number of delayed series.

Third, Group B is a separate single-arm population. Its 100.0% response estimate and 95% Wilson interval describe that group, but they do not provide a randomized within-population comparison with another vaccine arm. Directly comparing Group B’s percentage with Group A’s would mix differences in population history with differences in treatment assignment.

Fourth, the primary endpoint denominators are smaller than total enrollment, and the reasons are not reported. Although the record defines the analysis population as eligible participants who initiated vaccination and had endpoint data, it does not describe missing-data handling, exclusions by arm, or sensitivity analyses. The original sample-size justification is also not reported in the registry record; the available sample-size illustrations are based on observed effects.

Finally, detailed safety attribution and follow-up timing are not reported. The event counts cannot establish that events were vaccine-related, and the antibody endpoint does not provide evidence about persistence or clinical hepatitis B outcomes. The non-inferiority margin and complete multiplicity procedures are not reported in the registry record either.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: B-Enhancement of HBV Vaccination in Persons Living With HIV (BEe-HIVe): Evaluation of HEPLISAV-B — NCT04193189.
• Registry record last updated 2025-07-20; status last verified 2025-07.
• Results first posted 2025-07-20.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

22. Record Summary

NCT04193189, “B-Enhancement of HBV Vaccination in Persons Living With HIV (BEe-HIVe): Evaluation of HEPLISAV-B,” was a completed randomized, parallel-group phase 3 trial sponsored by the National Institute of Allergy and Infectious Diseases. Enrollment was 638. The study had no masking and evaluated two study populations: prior hepatitis B vaccine recipients deemed non-responders and people naïve to hepatitis B vaccination.

Group A received two-injection HEPLISAV-B, three-injection HEPLISAV-B, or three-injection ENGERIX-B; Group B received three-injection HEPLISAV-B. The primary outcome was the percentage meeting the anti-HBs seroprotection threshold at schedule-specific time points. Reported response percentages were 93.1%, 99.4%, 80.6%, and 100.0%, respectively. Sponsor comparisons, recalculated contrasts, and safety counts describe different aspects of the posted results and should be interpreted with their populations, methods, and reporting limits in mind.