Statement of Principles concerning chickenpox (Reasonable Hypothesis) (No. 29 of 2023)

The instrument directly affects any person who renders relevant service as defined: veterans with operational, peacekeeping, hazardous, or British nuclear test defence service under the VEA, and members with warlike or non-warlike service under the MRCA. This includes current and former Australian Defence Force personnel, peacekeepers, and certain British nuclear test participants. It also affects their dependants and legal personal representatives who make claims for compensation or pension for chickenpox or death from chickenpox.

Indirectly, the instrument binds the Repatriation Commission, the Military Rehabilitation and Compensation Commission, the Veterans’ Review Board, and the Administrative Appeals Tribunal when determining whether chickenpox is related to service. Medical practitioners providing reports for claims must understand the precise definitions of exposure, immunosuppression, and temporal windows to give useful opinions. Legal practitioners representing veterans must know which factor applies and whether the evidence can satisfy the minimum requirements.

The instrument also affects the Department of Veterans’ Affairs and the contracted service providers who assess claims. They must apply it as binding law, not merely as a guideline. Failure to correctly apply the instrument can lead to erroneous rejection or acceptance of claims, and subsequent review.

Note that the instrument does not affect civilians, private health insurers, or state workers’ compensation schemes. Its operation is confined to the Commonwealth military compensation systems under the VEA and MRCA.

The instrument imposes no new duties on individual veterans or members; rather, it confers a right: if a claimant can demonstrate at least one of the six factors exists and is related to their relevant service, then a reasonable hypothesis connecting chickenpox to service is deemed raised. The decision-maker must then proceed on that basis unless the contrary is proved (beyond reasonable doubt for VEA operational service, or on the balance of probabilities for MRCA and other VEA service types). This is a significant procedural advantage for the claimant, as it shifts the evidentiary burden.

However, the instrument also limits the right by specifying narrow definitions and temporal windows. For example, factor (2) for vaccine strain chickenpox requires isolation of the vaccine strain from lesions, which is rarely performed in clinical practice. Factor (3) for prevention of vaccination requires proof that the person was “prevented from accessing appropriate varicella-zoster vaccination in accordance with contemporary medical standards of the time” and that the onset occurred between 1 and 10 years after the prevention. This factor creates a duty on the decision-maker to assess both the medical standards of the time and the cause of the prevention.

Factor (6), inability to obtain appropriate clinical management for chickenpox, is broad but explicitly limited to material contribution to or aggravation of chickenpox under section 10(2). It places a duty on the decision-maker to consider what constituted appropriate clinical management and whether the inability was due to service circumstances. This could cover situations where a person was deployed to a remote area without access to antiviral therapy, for instance.

Section 11 incorporates other SoPs: if a factor refers to an injury or disease covered by a different SoP (e.g., if an immunosuppressive drug causing an immunocompromised state is itself the subject of a separate SoP), the factors in that other SoP apply. This means a claimant may need to also satisfy an additional SoP for the underlying condition to establish the chickenpox factor - a cascading compliance burden.

This instrument does not create any penalties for non-compliance by claimants or their representatives. Enforcement mechanisms are indirect: incorrect application of the instrument may lead to administrative review or appeal. The Repatriation Commission and the Military Rehabilitation and Compensation Commission must apply it correctly, and their decisions are reviewable by the Veterans’ Review Board and the Administrative Appeals Tribunal. A decision-maker who disregards the instrument could have a decision set aside or remitted.

There is no criminal penalty for making a false claim under this instrument; false statements in relation to a claim fall under the broader provisions of the Criminal Code (e.g., s 135.1 for obtaining a financial advantage by deception) or the Social Security (Administration) Act, but not this SoP. The instrument itself is silent on enforcement, being purely a causation-standard-setting tool.

The practical enforcement risk lies in the cost and time of litigation. If a claimant fails to satisfy any factor, the decision-maker can reject the claim without having to disprove a reasonable hypothesis. Given the narrow definitions, especially of “immunocompromised state as specified” and the high bar for vaccine strain isolation, many claims may be rejected at the initial stage, forcing applicants into time-consuming and stressful review processes. This imposes real transaction costs on claimants, who may need to obtain expert medical evidence to prove exposure windows or immunosuppression. There is no automatic penalty for the department if it incorrectly rejects a claim, but it may be ordered to pay costs in tribunal reviews.

The instrument is made under subsection 196B(2) of the VEA, which specifically requires the RMA to determine SoPs for the purpose of claims under the VEA and the MRCA. It operates alongside other SoPs: if a factor refers to an injury or disease covered by another SoP (e.g., chronic renal failure or haematological malignancy), section 11 incorporates those SoPs by reference. This means the reasonable hypothesis connection for chickenpox may depend on first establishing a reasonable hypothesis for another condition. For example, a claimant relying on factor (4) - being in an immunocompromised state as specified at the time of clinical worsening - would need to satisfy the relevant SoP for the underlying immunosuppressive condition, such as HIV or chronic renal failure. This creates a cascading burden of proof.

The instrument also interacts with the substantive provisions of the VEA and MRCA that govern the standard of proof. For operational service under the VEA, once a reasonable hypothesis is raised, the Commission must accept the connection unless the contrary is proved beyond reasonable doubt (ss 120(1), 120A). For non-operational service, the standard is reasonable satisfaction (balance of probabilities) under ss 120(4), 120A. For MRCA claims, section 338 applies and incorporates similar standards.

The instrument does not replace or override the general causation provisions in those Acts; it merely supplies the minimum factors to raise a hypothesis. It also does not affect other eligibility criteria such as service requirements, incapacity, or death provisions.

There is no interaction with state workers’ compensation or private insurance because the instrument is federal and limited to military service. However, if a veteran also claims under common law against a third party (e.g., a vaccine manufacturer), this SoP may be referenced as an expert opinion on causation, but it is not binding in civil proceedings.

This instrument, No. 29 of 2023, repeals and replaces the Statement of Principles concerning chickenpox No. 87 of 2015 (F2015L00919). The 2015 instrument was itself a replacement of earlier versions dating back to the original SoP under subsection 196B(2) of the VEA. The 2023 version makes several changes from the 2015 instrument based on updated medical-scientific evidence. Notably, the new instrument adds factor (3) - prevention from accessing appropriate varicella-zoster vaccination - which did not appear in the 2015 version. The 2015 SoP had a factor covering “being in a close contact environment for at least 10 hours per week” but that language has been removed and replaced with the current exposure definition. The temporal windows for exposure in immunocompromised persons have also changed: the 2015 SoP had a single 10-21 day window for all exposures; the 2023 version extends it to 10-28 days for those who are immunocompromised or have received prophylaxis. The definition of “being exposed to the varicella-zoster virus” has been refined to include inhalation of droplet nuclei and contamination with articles within two days, which is more specific than the prior wording.

The instrument was made on 24 April 2023 and commenced on 23 May 2023. It applies to claims made on or after that date, as well as un-finalised claims pending under section 5 read with sections 120A VEA and 338 MRCA. This is standard operation for SoP amendments.

No further amendments have been made to No. 29 of 2023 as of the date of this instrument (the source text provided is the final version). Future amendments will occur if the RMA reviews the medical evidence.

As a recent instrument (effective May 2023), there is no reported litigation specifically concerning SoP No. 29 of 2023 itself. However, the predecessor SoP (No. 87 of 2015) was considered in a number of AAT and VRB decisions. The key issue in those cases was the interpretation of “being in close contact” and the temporal window for exposure. Some tribunal decisions emphasised that the exposure must be proven by direct evidence, not speculation. The new instrument’s refined definition of exposure and the addition of droplet nuclei inhalation may reduce ambiguity but will still require careful fact-finding.

The factor regarding prevention of vaccination is entirely new. It may generate litigation over what constitutes “contemporary medical standards of the time” and whether the prevention was due to service circumstances. For example, if a veteran was deployed to a remote location where varicella vaccine was not stocked, does that constitute prevention? The instrument does not require the prevention to be due to service; the factor only requires that the prevention existed, and the relationship to service is established under section 10(1) separately. This could lead to disputes over whether failure to offer vaccination counts as prevention.

The high bar for vaccine strain chickenpox (isolation of vaccine strain from lesions) has not been litigated under the new instrument but was rarely successful under the old one because the test is rarely performed. It is likely to remain a dead letter.

The immunocompromised state as specified definition is narrow, and earlier decisions have found that conditions such as steroid-induced immunosuppression from cortisone injections did not fall within “immunosuppressive drug” as specified. The new instrument retains the same limited categories, so those precedents remain relevant.

Overall, litigation will likely focus on the factual sufficiency of exposure evidence rather than on the legal meaning of the instrument. The instrument is designed to be specific enough to minimise interpretive disputes, but the new vaccination factor may generate novel litigation.

Several traps exist for claimants and their representatives.

First, the definition of chickenpox excludes shingles and postherpetic neuralgia. A veteran who presents with shingles (reactivation of varicella-zoster) cannot rely on this SoP; they would need the SoP for shingles. This is a common misunderstanding.

Second, factor (2) for vaccine strain chickenpox requires isolation of the vaccine strain from lesions. This is rarely done and effectively makes this factor unusable unless the veteran had a documented PCR test that specifically identified the vaccine strain. Routine testing does not distinguish vaccine from wild-type virus.

Third, factor (3) (prevention of vaccination) requires that the person was “prevented from accessing” the vaccine. This means the prevention must be actual, not mere lack of access. Contemporary medical standards at the time also need to be established. The 1 to 10 year window before clinical onset is unusually long and may be hard to prove.

Fourth, the immunocompromised state as specified is very limited. A person with diabetes, even severe, does not qualify. A person receiving low-dose methotrexate for psoriasis does qualify if it is an immunosuppressive drug, but the definition does not list specific drugs; it depends on whether the drug is immunosuppressive in the clinical judgement. However, corticosteroids are immunosuppressive but short courses may not satisfy “treatment with an immunosuppressive drug” if the duration is irrelevant - the definition does not specify duration, so any treatment qualifies.

Fifth, the exposure windows are strict. For factor (1)(a), the exposure must occur between 10 and 21 days before clinical onset. For immunocompromised or post-prophylaxis persons, the window is 10 to 28 days. Missing the window by even one day defeats the factor. Note that the instrument does not allow for any degree of uncertainty - the evidence must show the exposure fell within that period.

Sixth, factor (6) (inability to obtain appropriate clinical management) is only available for clinical worsening, not initial onset. If a veteran contracted chickenpox before service and then during service could not get treatment, they may use this factor to claim aggravation, but they cannot claim the condition itself is service-related.

Seventh, section 11 creates a cross-reference trap. If a veteran relies on factor (1) because they were in an immunocompromised state due to a haematological malignancy, and that malignancy itself is the subject of another SoP, the veteran must also satisfy the factors in that SoP. So a claim for chickenpox may require two separate SoP analyses.

Eighth, the instrument does not specify what constitutes “appropriate clinical management” for factor (6). Is it simply antiviral therapy? Hospitalisation? It will be open to interpretation, creating uncertainty.

For a claimant seeking to establish that chickenpox is related to service, compliance means proving at least one factor from section 9 exists and is related to relevant service under section 10. Practically, this requires gathering medical evidence to support the factor.

For factor (1) (exposure), the best evidence is a documented close contact with a person known to have active chickenpox within the 10-21 or 10-28 day window. Statements from witnesses, medical records, or unit logs showing an outbreak may be admitted. For the extended window, the claimant must show they were immunocompromised as specified or had received varicella-zoster immunoglobulin as prophylaxis. Medical records of immunosuppressive drug treatment or HIV infection are necessary.

For factor (2) (vaccine strain), the claimant must have laboratory evidence of vaccine strain isolation from vesicle lesions. This is almost never routine; therefore, this factor is rarely viable.

For factor (3) (prevention of vaccination), the claimant must show that at some point 1 to 10 years before onset, they were prevented from accessing vaccination consistent with medical standards of the time. This may require evidence of a specific policy or order denying vaccination, or a deployment that prevented access despite willingness. Medical records showing prior varicella susceptibility and a request for vaccine that was denied would help.

For factors (4) and (5) (immunocompromised state or pregnancy at time of clinical worsening), the claimant must demonstrate the worsening occurred during service or due to service conditions. Medical records showing deterioration in service are key.

For factor (6) (inability to obtain appropriate clinical management), the claimant must show that during service they could not access treatment (e.g., antivirals, hospital care) for chickenpox, and that this inability caused worsening. Evidence of deployment to remote areas, lack of medical supplies, or refusal of treatment by service medical officers would be relevant.

Decision-makers must apply the instrument strictly. They should check whether the chickenpox definition is satisfied (exclude shingles). They must verify the temporal windows precisely. They must also consider section 11 cross-references to other SoPs. If a factor refers to an injury covered by another SoP, they must determine whether that SoP’s factors are met. This requires familiarity with multiple SoPs.

Given the limited immunocompromised categories and narrow definitions, many claims will fail at the factor existence stage. Practitioners should advise clients that the likely viable factors are exposure (if witnessed) or possibly inability to obtain management (if in a combat zone). The new vaccination prevention factor may be pursued but is fact-intensive. Overall, the instrument raises the evidentiary bar compared to a simple general causation argument; compliance means meeting the precise legal criteria, not just proving that chickenpox could theoretically be linked to service.