PUBLISHED

UNITED STATES COURT OF APPEALS

FOR THE FOURTH CIRCUIT

UNITED STATES OF AMERICA, 

Plaintiff-Appellant,

v.  No. 02-1351

ST. LOUIS UNIVERSITY, a corporation,

Defendant-Appellee. 

Appeal from the United States District Court

for the District of Maryland, at Baltimore.

J. Frederick Motz, District Judge.

(CA-95-3639-JFM)

Argued: January 22, 2003

Decided: July 16, 2003

Before NIEMEYER, LUTTIG, and TRAXLER, Circuit Judges.

Reversed and remanded by published opinion. Judge Traxler wrote

the majority opinion, in which Judge Niemeyer joined. Judge Luttig

wrote a dissenting opinion. 

COUNSEL

ARGUED: Mary McElroy Leach, Senior Trial Counsel, UNITED

STATES DEPARTMENT OF JUSTICE, Washington, D.C., for

Appellant. Marc Simon Moller, KREINDLER & KREINDLER, New

York, New York, for Appellee. ON BRIEF: Robert D. McCallum,

Jr., Assistant Attorney General, Thomas M. DiBiagio, United States

Attorney, Jeffrey Axelrad, Director, Torts Branch, Civil Division,
UNITED STATES DEPARTMENT OF JUSTICE, Washington,

D.C.; Daniel E. Troy, Chief Counsel, Eric M. Blumberg, Deputy

Chief Counsel for Litigation, Michael N. Druckman, Associate Chief

Counsel for Biologics, U.S. FOOD & DRUG ADMINISTRATION,

Rockville, Maryland; Alex M. Azar, II, General Counsel, DEPARTMENT OF HEALTH AND HUMAN SERVICES, Washington, D.C.,

for Appellant. Mark R. Dunn, HERZOG, CREBS & MCGHEE,

L.L.P., St. Louis, Missouri; Stanley P. Kops, Bala Cynwyd, Pennsylvania; Rex Carr, CARR, KOREIN, TILLERY, KUNIN, MONTROY

& GLASS, East St. Louis, Missouri, for Appellee.

OPINION

TRAXLER, Circuit Judge: 

St. Louis University ("SLU") paid a $16 million Missouri statecourt judgment to the family of a boy who became paralyzed after

receiving Orimune, an oral polio vaccine. SLU sought contribution

from American Cyanamid, the parent company of the vaccine manufacturer, and United States government, which tested and approved

the vaccine. The district court granted summary judgment in favor of

Cyanamid and the government, concluding that SLU’s contribution

claims were barred by principles of collateral estoppel. We reversed

and remanded. See St. Louis Univ. v. United States, No. 99-2227 (4th

Cir. March 1, 2001); American Cyanamid v. St. Louis Univ., No. 99-

2224 (4th Cir. March 1, 2001). After remand, on motions and crossmotions for summary judgment, the district court concluded that the

government, but not Cyanamid, was liable in contribution to SLU.

The government appeals the district court’s conclusion that it can be

required to contribute to the state-court judgment entered against SLU.1

We reverse and remand. 

1

In American Cyanamid Co. v. St. Louis University, No. 02-1235, SLU

appeals the district court’s rejection of its contribution claim asserted

against Cyanamid. We address that appeal in a separate opinion. 

2 UNITED STATES v. ST. LOUIS UNIVERSITY
I. BACKGROUND

A. The Vaccine

There are three types of poliomyelitis; "Type I can be contracted

only from a Type I virus, Type II only from a Type II virus and Type

III only from a Type III virus." In re Sabin Oral Polio Vaccine Prods.

Liab. Litig., 743 F. Supp. 410, 412 (D. Md. 1990). In the 1950s, an

oral polio vaccine ("OPV") was developed that used a live but attenuated or weakened polio virus. "Like all vaccines cultivated from live

viruses, OPV creates immunity by inducing a mild infection in the

recipient." Stuart v. American Cyanamid Co., 158 F.3d 622, 625 (2d

Cir. 1998). However, OPV also carries with it a risk that a recipient

(or someone in close contact with the recipient) will contract the disease through the vaccine. 

OPV is produced by passing wild virus of each type through an

animal host to develop a "strain" of attenuated virus. The vaccine

manufacturer uses the strain to grow a "seed" of each type of virus,

the seeds are used to produce monopools of each type of virus, and

"lots" of that virus type are derived from the monopools. Lots from

each type of virus are then combined into a single "trivalent" pool,

from which a trivalent vaccine can be produced to protect against all

three types of polio. See Berkovitz v. United States, 486 U.S. 531, 541

(1988). 

The United States government approved OPV in 1960 and in 1961

adopted regulations governing the manufacture of the vaccine. The

regulations required OPV to satisfy certain "neurovirulence" tests.

Neurovirulence is the capacity of an infectious agent to produce pathologic effects on the central nervous system. In

this context, it refers to the vaccine’s ability to cause paralytic poliomyelitis. The neurovirulence of a vaccine product

is tested by injecting the product into monkeys. The product

meets the neurovirulence criterion only if a specified number of the animals survive and a comparative analysis demonstrates that the neurovirulence of the vaccine product does

not exceed the neurovirulence of a reference product previously selected by the agency. 

UNITED STATES v. ST. LOUIS UNIVERSITY 3
Berkovitz, 486 U.S. at 545 n.9 (internal quotation marks omitted).

Under the original OPV regulations, a given monopool could be used

to produce vaccine only if its neurovirulence did not exceed that of

the reference vaccine and the monopool was one of five consecutively

made monopools that all satisfied the monkey neurovirulence test. 

The government substantially amended the monkey neurovirulence

regulations in 1991, in part because studies did not show a correlation

between higher neurovirulence scores in monkeys and the incidence

of vaccine-associated polio in humans. See Additional Standards for

Viral Vaccines, 56 Fed. Reg. 21418, 21420 (May 8, 1991) ("No single

vaccine lot has been associated with an increased incidence of poliomyelitis. The lots that have been identified as associated with a case

of paralytic poliomyelitis have had typically low scores when tested

by FDA and the manufacturer for neurovirulence in monkeys."). In

1996, the FDA repealed a number of regulations, including the oral

polio vaccine regulations. See Revocation of Certain Regulations, 61

Fed. Reg. 40153, 40155 (August 1, 1996). 

B. The State Court Action

The state-court judgment paid by SLU arose from SLU’s actions

in treating 3-month old Danny Callahan. Approximately one month

after receiving a dose of Orimune, Danny developed a fever and a

perirectal abscess. He was treated at Cardinal Glennon Hospital by

hospital and SLU employees. Although the abscess improved,

Danny’s legs and left arm were permanently paralyzed. Type III polio

virus was isolated in Danny’s stool, and doctors ultimately concluded

that Danny suffered from vaccine-associated polio. 

The plaintiffs’ theory of the case was that SLU improperly treated

Danny’s abscess by giving him the wrong kind of antibiotic. The

improper treatment allowed the release of endotoxins, which suppressed Danny’s immune system during a time when the polio virus

from the vaccine was still replicating in Danny’s gastrointestinal tract.

Because Danny’s immune system was compromised, the attenuated

polio virus in the vaccine was able to replicate fast enough to overcome his suppressed immune system, resulting in poliomyelitis. The

plaintiffs’ experts testified that if the abscess had immediately been

incised and drained as required by the standard of care, and if Danny

4 UNITED STATES v. ST. LOUIS UNIVERSITY
had been treated with an appropriate antibiotic, the endotoxins would

not have been released and his immune system would not have been

suppressed. Thus, the expert witnesses testified that if Danny had

been treated properly, he would not have been paralyzed by the polio

vaccine. The jury’s $16 million verdict in favor of the plaintiffs was

affirmed by the Missouri Supreme Court. See Callahan v. Cardinal

Glennon Hosp., 863 S.W.2d 852 (1993) (en banc). 

C. In re Sabin

While Callahan v. Cardinal Glennon Hospital was proceeding

through the Missouri state courts, multi-district Orimune cases filed

against the United States government under the Federal Tort Claims

Act were transferred to the District of Maryland for resolution of the

common legal and factual questions. See In re Sabin Oral Polio Vaccine Prods. Liab. Litig., 743 F. Supp. 410 (D. Md. 1990); In re Sabin

Oral Polio Vaccine Prods. Liab. Litig., 763 F. Supp. 811 (D. Md.

1991); In re Sabin Oral Polio Vaccine Prods. Liab. Litig., 774 F.

Supp. 952 (D. Md. 1991) ("Sabin III").2 The Sabin plaintiffs contracted polio after receiving the Orimune vaccine or after coming into

contact with a recipient of the vaccine. They sued the government,

alleging, inter alia, that the government negligently approved for

release the vaccine lots which contained the doses given to the plaintiffs, even though the vaccine seeds from which the lots were derived

did not meet the neurovirulence standards set forth in the governing

regulations. 

The district court ultimately concluded that the government could

be held liable for approving vaccine lots that did not comply with the

regulatory requirements for neurovirulence. Applying the "Good

Samaritan" principles of the Restatement (Second) of Torts, the district court determined that the government, by violating its own regulatory standards and approving for release vaccine derived from seeds

that exceeded the neurovirulence standards, had increased the risk of

harm for those receiving the vaccine, which proximately caused the

plaintiffs’ injuries. Sabin III, 774 F. Supp. at 958. This court affirmed

the district court’s causation and liability determination. See In re

2The district judge presiding over the cases currently before us also

presided over the In re Sabin cases. 

UNITED STATES v. ST. LOUIS UNIVERSITY 5
Sabin Oral Polio Vaccine Prods. Liab. Litig., 984 F.2d 124 (4th Cir.

1993) (per curiam) ("Sabin IV"). The Orimune vaccine received by

Danny Callahan was derived from one of the vaccine seeds that the

district court in the Sabin cases concluded were improperly approved

by the government. 

II. THE CONTRIBUTION ACTION

After the Missouri Supreme Court affirmed the Callahan verdict,

SLU filed a contribution action in Maryland against the United States,

alleging that Danny Callahan’s polio was caused by the governmental

failings identified in the Sabin cases. The government moved for partial summary judgment, arguing that SLU was barred by collateral

estoppel from relitigating the Callahan jury’s conclusion that SLU’s

malpractice caused Danny’s polio. The district court agreed, concluding that SLU was prohibited from relitigating the facts that the court

believed the Callahan jury necessarily found in order to reach its verdict against SLU: (1) that SLU breached the applicable standard of

care when treating Danny’s abscess; (2) that Danny’s immune system

would not have been suppressed but for SLU’s inadequate treatment

of the abscess; (3) that, but for the suppressed state of Danny’s

immune system, the live polio virus contained in the vaccine would

not have been able to replicate fast enough to cause polio; and (4)

that, but for SLU’s negligence, Danny would not be paralyzed. The

district court’s collateral estoppel order prevented SLU from arguing

that it was not negligent at all or that any negligence on its part did

not contribute to Danny’s polio, but the ruling allowed SLU to proceed on any theory consistent with the Callahan verdict. Thus, after

the collateral estoppel order, SLU could still prevail if it could establish that an immunosuppressed child would not have contracted polio

from a vaccine that complied with all regulatory requirements. 

After the collateral estoppel ruling, the parties engaged in eighteen

months of discovery. The government then moved for summary judgment on the ground that SLU could not prove that the government’s

negligence caused Danny’s polio. The district court reviewed the evidence submitted by SLU and concluded that it was insufficient, given

the Callahan findings, to establish a causal connection between the

government’s negligence and Danny’s injuries. The district court

6 UNITED STATES v. ST. LOUIS UNIVERSITY
therefore granted summary judgment to the government on SLU’s

contribution claim. 

We reversed and remanded, concluding that the district court

improperly applied Missouri law when it held that the Callahan jury

verdict had collateral estoppel effect on SLU’s contribution action

against the government. We explained that Missouri law did not limit

SLU to causation theories predicated on the Callahan jury’s implicit

conclusion that Danny would not have contracted polio but for SLU’s

negligence which resulted in the suppression of his immune system.

However, the district court had limited SLU during discovery to causation theories consistent with its ruling as to the collateral estoppel

effect of the Callahan judgment, and the district court premised its

order granting summary judgment on SLU’s failure to present evidence of causation consistent with its collateral estoppel ruling.

Because of the district court’s error with regard to the collateral estoppel issue, we reversed the district court’s grant of summary judgment

to allow SLU an opportunity to develop other appropriate theories of

causation. 

After remand, SLU offered no new evidence, deposed no new witnesses, and offered no new theory of causation. Instead, it relied

almost exclusively on the fact that in the Sabin cases, the court determined that the government’s regulatory violations caused the injuries

at issue. SLU argued that Danny Callahan’s polio vaccine came from

one of the seeds that the district court in Sabin had concluded the government negligently approved in violation of its own regulatory standards. Since the Sabin court had concluded that the government’s

failings proximately caused the injuries of the Sabin plaintiffs, SLU

suggested that those same regulatory violations must also be held to

have proximately caused Danny’s injuries. 

The district court agreed with SLU. Applying the same analysis the

court had used in Sabin III, the district court concluded that the government’s negligence in approving vaccine that did not satisfy the

neurovirulence standards caused Danny’s polio. The district court

therefore granted partial summary judgment to SLU, concluding that

the government was liable in contribution to SLU, but reserving for

UNITED STATES v. ST. LOUIS UNIVERSITY 7
later the determination of the extent of the government’s liability to

SLU.3

III. ANALYSIS

The government’s liability in contribution, of course, is dependent

on SLU’s ability to establish that the government can be held liable

on the tort claim in the underlying action. See United States v. Yellow

Cab Co., 340 U.S. 543, 546-50 (1951) (concluding that the waiver of

sovereign immunity under the Federal Tort Claims Act encompasses

claims for contribution if the law of the relevant state would hold a

private individual liable for contribution in the same circumstances);

Gramex Corp. v. Green Supply, Inc., 89 S.W.3d 432, 442 (Mo. 2002)

(en banc) ("To maintain an action for contribution, both the party

seeking contribution and the defendant against whom contribution is

sought must be tortfeasors, originally liable to the plaintiff-injured

party." (alterations and internal quotation marks omitted)). The government contends that SLU presented no evidence showing that the

government’s violations of the original polio vaccine regulations

proximately caused the injuries suffered by Danny Callahan. According to the government, the district court’s approach to the case

amounts to the imposition of absolute liability for the government,

which is inconsistent with the requirements of the Federal Tort

Claims Act and does not meet the causation requirements of Missouri

law. Given the absence of any admissible proximate cause evidence,

the government contends that the district court must have reached its

decision by giving collateral estoppel effect to its decision in Sabin

III, but that collateral estoppel cannot be applied against the government in this case. 

A.

We first consider the government’s arguments as to whether the

decisions in the Sabin cases must be given controlling effect in this

litigation. At the outset, we can dispense with the government’s claim

that the district court improperly gave collateral estoppel effect to the

3The district court certified the order as appropriate for immediate

review, and this court granted the government permission to bring this

interlocutory appeal. See 28 U.S.C.A. § 1292(b) (West 1993). 

8 UNITED STATES v. ST. LOUIS UNIVERSITY
Sabin decisions, an action which might well have been error. See

United States v. Mendoza, 464 U.S. 154, 162 (1984) (rejecting the use

of offensive nonmutual collateral estoppel against the government).

The district court expressly did not give the Sabin cases collateral

estoppel effect. Instead, it appears that the court viewed the cases as

establishing binding precedent on the question of proximate cause.

See St. Louis Univ. v. United States, 182 F. Supp. 2d 494, 500 n.5 (D.

Md. 2002) ("I am not relying upon the doctrine of collateral estoppel,

which may not be invocable against the government. I am simply following my reasoning in Sabin III that was affirmed on appeal." (citation omitted)). The question, then, is whether Sabin III and our

decision in Sabin IV serve as binding precedent in this case. We think

the answer to that question is no. 

Under the Federal Tort Claims Act, state law, not federal law,

serves as "the source of substantive liability." FDIC v. Meyer, 510

U.S. 471, 478 (1994). The Act requires the government’s liability to

be determined "in accordance with the law of the place where the act

or omission occurred." 28 U.S.C.A. § 1346(b)(1) (West Supp. 2003).

The Supreme Court has concluded that the "law of the place" refers

to the "whole law," including choice-of-law principles of the state

where the negligent act or omission occurred. See Richards v. United

States, 369 U.S. 1, 11 (1962). 

Because the government’s actions with regard to the polio vaccine

took place in Maryland, see Sabin III, 774 F. Supp. at 953-54, Maryland law, including its choice-of-law principles, governs this case, just

as it governed the Sabin cases. Under Maryland’s choice-of-law principles, the law to be applied in tort cases is the law of the state where

the injury was suffered, not where the negligent act occurred. See

Johnson v. Oroweat Foods, Inc., 785 F.2d 503, 511 (4th Cir. 1986).

Danny Callahan was injured in Missouri, so Missouri law applies to

SLU’s claim against the government. But the plaintiffs in the Sabin

cases were residents of Maryland and Florida and suffered their injuries in those states. Thus, the proximate cause determination in Sabin

III was reached by applying Maryland and Florida law, while the

proximate cause determination in this case must be made by applying

Missouri law. Accordingly, notwithstanding the factual overlap of the

UNITED STATES v. ST. LOUIS UNIVERSITY 9
cases, the analyses of Sabin III and Sabin IV simply do not govern

this case.4

B.

Under Missouri law, a plaintiff seeking to hold a defendant liable

in tort must establish the existence of a duty on the part of the defendant to protect the plaintiff, a breach of that duty, and damages caused

by the breach. See, e.g., L.A.C. ex rel. D.C. v. Ward Parkway Shopping Ctr. Co., 75 S.W.3d 247, 257 (Mo. 2002) (en banc). In this case

(and the Sabin cases), the district court concluded that the government’s duty arose under the "Good Samaritan" doctrine, through

which liability may be imposed for the negligent execution of voluntarily undertaken duties. See Hoover’s Dairy, Inc. v. Mid-America

Dairymen, 700 S.W.2d 426, 432-33 (Mo. 1985) (en banc) (following

Good Samaritan standards set forth in Restatement (Second) of Torts

§§ 323, 324A (1965)). For purposes of this litigation, the government

has agreed to be bound by the findings in the Sabin cases that it

breached its duty by violating the OPV regulations. See St. Louis

Univ., 182 F. Supp. 2d at 498. Thus, the only issue before the district

court was whether SLU could establish that Danny Callahan’s injuries

were caused by the government’s breach of duty. 

The district court concluded that SLU had sufficiently established

that the government’s regulatory violations caused Callahan’s injuries. The court explained that in Sabin III,

I held that proximate cause was established by the mere fact

that if seeds 45 B 85 and 45 B 165 had not been in use, the

vaccine giving rise to the injuries would not have been manufactured. The evidence clearly establishes that but for the

United States’s negligence, the seeds would not have been

used. I went on to reject an ancillary contention made by the

4Even assuming that SLU is correct in its contention that the tort laws

of Maryland and Missouri are similar, it makes little sense for this court

to apply Missouri law by way of Sabin III and Sabin IV, cases that

applied Maryland and Florida law. Instead, we will go directly to the

source and consult Missouri cases to determine whether SLU has satisfied the requirements of Missouri law. 

10 UNITED STATES v. ST. LOUIS UNIVERSITY
government that proximate cause was dispelled by the fact

that the specific lots involved in the two cases under consideration had met the regulatory neurovirulence criteria, and

I concluded that the causal connection between the regulatory violations and plaintiffs’ injuries are logical, sensible

and direct. The Fourth Circuit affirmed this holding on

appeal. 

My reasoning in Sabin III is equally applicable here. This

can be most easily seen by hypothesizing that SLU is correct

in contending that the immunosuppression allegedly caused

by its malpractice played absolutely no role in making Callahan susceptible to contracting polio from OPV. If that is

true, Callahan stands in exactly the same position as did the

plaintiffs in other Sabin cases because in that event the sole

cause of his polio was the vaccine. Likewise, even if the

immunosuppression did play some role in the disease process, Callahan’s exposure to the oral vaccine had to be a

contributing cause to his paralysis. The isolation of Type III

polio virus in Callahan’s stool demonstrates he contracted

polio, and no one suggests that the immunosuppression

alone could have caused the disease. Accordingly, as I held

in Sabin III, Callahan was exposed to the virus as a consequence of the government’s violation of the OPV regulations. If the government had not wrongfully approved the

seed from which the vaccine was derived, Callahan would

never have been administered a dose of Orimune and would

never have contracted polio even if he had been immunosuppressed. This "but for" relationship meets the standard of

proximate cause under Missouri law just as it does under the

law of Maryland and Florida applicable in Sabin III. 

St. Louis Univ., 182 F. Supp. 2d at 499-500 (footnotes, alterations,

and internal quotation marks omitted)).

We assume, of course, that Sabin III and Sabin IV properly applied

Maryland and Florida law.5 Nonetheless, it is clear that the approach

5The government points out that when this court in Sabin IV affirmed

the proximate cause analysis in Sabin III, we relied on Waffen v. United

UNITED STATES v. ST. LOUIS UNIVERSITY 11
taken in the Sabin cases is inconsistent with the requirements of Missouri law, which governs this case. Under Missouri law, a plaintiff

must establish both causation-in-fact and proximate cause. See

Callahan, 863 S.W.2d at 862, 865; Robinson v. Missouri State Highway & Transp. Comm’n, 24 S.W.3d 67, 77 (Mo. Ct. App. 2000) (per

curiam).

A defendant’s conduct is the cause in fact of a plaintiff’s

injuries where the injuries would not have occurred but for

that conduct. Proximate cause is not causation in fact, but is

a limitation the law imposes upon the right to recover for the

consequences of a negligent act. The requirement of proving

proximate cause absolves those actors whom it would be

unfair to punish because of the attenuated relation which

their conduct bears to the plaintiff’s injury. 

Robinson, 24 S.W.3d at 77 (citations and internal quotation marks

omitted). The district court’s conclusion that Danny Callahan would

not have contracted polio "but for" the government’s action thus goes

only to the question of causation-in-fact, not proximate cause,

because it does not answer the question of whether the particular

result that occurred was a reasonable and probable consequence of the

government’s conduct. See Callahan, 863 S.W.2d at 865 (Missouri

courts "have generally said that the injury must be a reasonable and

probable consequence of the act or omission of the defendant."). 

The district court’s explanation of why different results were

required as to the claims against the government and Cyanamid, the

States Department of Health & Human Services, 799 F.2d 911 (4th Cir.

1986), which considered causation requirements under Maryland law in

the context of a claim for loss of chance of survival. Subsequent cases

from this court and Maryland state courts have indicated that Waffen did

not accurately articulate the contours of Maryland’s proximate cause

requirements. See Hurley v. United States, 923 F.2d 1091, 1096 (4th Cir.

1991) ("Our interpretation of Maryland law in Waffen is called into question because we were interpreting Maryland law as espoused in Hetrick

v. Weimer, which was later reversed by the Maryland Court of Appeals."

(footnote omitted)); Cooper v. Hartman, 533 A.2d 1294, 1297 & n.4

(Md. 1987) (placing Waffen among a group of decisions that improperly

"relaxed the standards regarding causation"). 

12 UNITED STATES v. ST. LOUIS UNIVERSITY
vaccine manufacturer, suggests that the court believed the causation

standard is different in cases where the duty arises under the Good

Samaritan doctrine. The court stated:

I find that Cyanamid cannot be held liable for contribution

to SLU and that it is therefore entitled to summary judgment. While I recognize that this holding may seem asymmetrical, paradoxical, or even perverse in light of my

finding that the government is liable for contribution, the

difference in result flows from the difference in the nature

of the respective duties owed by the United States and Cyanamid to those who were exposed to the live virus contained

in OPV. 

As indicated above, in Sabin III I ruled that the Good

Samaritan doctrine and its parallel provision, Restatement

(Second) of Torts § 323, imposed upon the government the

duty not to approve vaccine seeds in violation of the OPV

regulations. Cyanamid was under no such duty. Its duties

and responsibilities to the members of the public, particularly to OPV recipients and their families, [are] defined by

products liability law. In considering claims against Cyanamid, the focus must therefore be on the safety of its product, not the regulatory process for which the government

bore responsibility. Likewise, in analyzing the element of

proximate cause in claims against Cyanamid, the focus must

be on whether the plaintiff can prove that it was a defect in

the OPV that resulted in his injury, not simply—as in a case

against the government—whether he had been exposed to

OPV derived from a seed that had been improperly

approved in violation of the regulatory process. Under Missouri law this element of causation is required whether a

plaintiff sues for strict liability, negligence, or breach of

warranty. 

St. Louis Univ., 182 F. Supp. 2d at 500. Missouri law, however,

makes it quite clear that the Good Samaritan doctrine is relevant to

the question of duty only; it has no effect on the general rules of causation. See Wollen v. DePaul Health Center, 828 S.W.2d 681, 683

(Mo. 1992) (en banc) ("[T]his Court has recognized that section 323

UNITED STATES v. ST. LOUIS UNIVERSITY 13
[of the Restatement (Second) of Torts] creates a duty of care. In creating this duty, this section of the Restatement defines a type of negligent behavior but does not alter the rules of causation." (citation

omitted)). Thus, SLU’s claim against the government requires evidence of proximate cause in addition to evidence of but-for causation.

As to proximate cause, we note that all OPV, including OPV that

satisfied all regulatory requirements, carried the risk that the recipient

would actually contract polio. Therefore, to show that Danny’s polio

was caused by the government’s regulatory violations, we conclude

that SLU was required to establish that Danny likely would not have

contacted polio (or would have contracted a less severe case of polio)

from a vaccine that satisfied the government’s neurovirulence requirements. Any lesser standard would result in the government being held

strictly liable for its regulatory violations, which would be inconsistent with Missouri law. See Sill v. Burlington No. R.R., 87 S.W.3d

386, 392 (Mo. Ct. App. 2002) (explaining that the violation of a statute can, under certain circumstances, support a negligence per se

claim, but that the plaintiff must prove that the statutory "violation

was the proximate cause of the injury."). And this evidence, of course,

must be in the form of expert testimony. See, e.g., Wright v. Barr, 62

S.W.3d 509, 524 (Mo. Ct. App. 2001) ("If there is a sophisticated

injury, one that requires surgical intervention or other highly scientific

techniques for diagnosis, expert medical testimony is required to

prove causation."). 

There is no such evidence in this record. At best, SLU’s experts

assumed that increased neurovirulence led to increased incidence of

vaccine-associated polio, but SLU’s experts did not offer that opinion.

In fact, none of SLU’s experts were even qualified to render such an

opinion.6 The district court recognized this absence of evidence, see

St. Louis Univ., 182 F. Supp. 2d at 502 ("Whether or not an oral polio

6

In the first appeal, this court noted that there was some evidence that

a more neurovirulent vaccine caused Danny to have a more severe case

of polio. SLU, however, did not pursue this theory after remand and does

not pursue it on appeal. Moreover, the district court concluded that the

expert who provided this testimony was not qualified to render an opinion on causation, and SLU does not challenge that determination on

appeal. 

14 UNITED STATES v. ST. LOUIS UNIVERSITY
vaccine that complied with the OPV regulations would have caused

Callahan and the plaintiffs in the other Sabin cases to contract polio

ultimately is unknowable and unprovable."), as does SLU. SLU, however, insists that it is not required to present evidence of proximate

cause. 

According to SLU, the regulations establishing the neurovirulence

standards created an "unrebuttable presumption" that any vaccine

exceeding the standards posed an unacceptable risk that the recipient

would contract polio. Brief of Appellee at 21. Thus, SLU contends

that once it was established in the Sabin cases that the government

violated its regulations and that the violations proximately caused the

injuries, the government was automatically liable for the injuries suffered by anyone who received a vaccine derived from one of the vaccine seeds at issue in the Sabin cases. As noted above, such an

approach is utterly inconsistent with Missouri law. See Sill, 87

S.W.3d at 392 ("If a submissible case is made under a negligence per

se cause of action, a plaintiff could recover if a jury concluded that

a statute was violated and the violation was the proximate cause of

the injury."); Friend v. Yokohama Tire Corp., 904 S.W.2d 575, 579

(Mo. Ct. App. 1995) ("One of the elements of a negligence per se

action is that the violation of a statute was the proximate cause of the

injury."). 

Because there is no evidence that the government’s regulatory violations proximately caused Danny’s injury, SLU has failed to show

that it is entitled to contribution from the government. We therefore

reverse the district court’s grant of partial summary judgment in favor

of SLU and we remand for the entry of judgment in favor of the government. See Monahan v. County of Chesterfield, Va., 95 F.3d 1263,

1265 (4th Cir. 1996) (explaining that where cross-motions for summary judgment have been filed, the appellate court can direct the

entry of judgment in favor of the appellant).

REVERSED AND REMANDED

LUTTIG, Circuit Judge, dissenting: 

I would affirm the district court’s judgment in this case under the

binding precedent of the circuit. In In re Sabin Oral Polio Vaccine

UNITED STATES v. ST. LOUIS UNIVERSITY 15
Products Liability Litigation, 984 F.2d 124 (4th Cir. 1993) ("Sabin

IV"), we determined that under a tort regime, identical in all relevant

respects to the one at issue here, an injury, identical to the one at issue

here, was proximately caused by tortious conduct identical to that

alleged here. On the basis of the reasoning which we adopted in that

case, I must conclude that our application here of Missouri state law

yields the conclusion that appellee SLU proffered sufficient evidence

to establish the legally necessary causation for it to prevail. 

The majority reaches the opposite conclusion. It reasons that "our

decision in Sabin IV [does not] serve as binding precedent in this

case," ante at 9, because "the proximate cause determination in Sabin

III was reached by applying Maryland and Florida law, while the

proximate cause determination in this case must be made by applying

Missouri law." Ante at 9. This reasoning would be compelling if SLU

proposed that we apply the state law holdings of Sabin IV to the facts

of the case before us today. But, the majority is wrong to suggest that

SLU, or by implication, I, argue that Sabin IV is binding as a matter

of Missouri state law. All that SLU asks, and all that I contend is

appropriate, is that we reach our judgment by applying the binding

reasoning of Sabin IV. 

While our decision in Sabin IV resulted in state law holdings, it

also produced reasoning, by which we reached those state law holdings. This reasoning is uniquely the creature of this court, and, as it

is binding upon us, we must apply it in other cases involving the same

predicate facts (i.e., functionally identical underlying tort regime,

facts, and causation theories). In this manner, Sabin IV binds us as a

matter of federal law, delimiting the open field that we would otherwise face in formulating our reasoning. Because the question before

us is simply how we will reason to our application of Missouri’s tort

regime, which regime is functionally identical in the relevant regards

to those from which we reasoned in Sabin IV, our conclusion as to

how to reason to this application is governed by Sabin IV. 

The majority, to its credit, does not attempt to deny the crucial

point in this case, namely, that in Sabin IV we reasoned from two

state tort law regimes, from injuries, and from asserted causation theories, that were functionally indistinguishable from those before us

today. But, absent such a denial, it has no basis on which to reach the

16 UNITED STATES v. ST. LOUIS UNIVERSITY
conclusion it reaches today other than that it disagrees with the reasoning we adopted in Sabin IV. While I am somewhat sympathetic to

the critique the majority implicitly levels at that reasoning, the majority, as am I, is bound to abide by it until this court en banc or the

Supreme Court holds otherwise. 

Having mistakenly rejected the authority of Sabin IV, the majority

asserts that the district court erred here because it engaged in no proximate cause determination whatsoever. But Sabin IV quite clearly

shows the majority to be in error on this point. There, we concluded

that an identical causation theory, in the unique circumstance where

the tortfeasor’s function is that of a product-approver, suffices to

establish proximate cause. We reasoned as follows:

The final point of appeal concerns the district court’s determination that [the government’s] approval of the lots was

the proximate cause of [the plaintiff’s] injuries. The test of

probable [sic] cause is one of "reasonable probability or reasonable certainty." In other words, "the plaintiff has the burden of introducing evidence which affords a reasonable

basis for the conclusion that it is more likely than not that

the conduct of the defendant was a substantial factor in

bringing about the result." 

The district court concluded: 

Regardless of the acceptability of the specific

lots from which were derived the vaccine . . . if

[the government] had properly applied 42 C.F.R.

§ 73.114(b)(1)(iii) . . . the seed would not have

been used. This is so because the manufacturer

would have been unable to satisfy the consistency

requirement found in 42 C.F.R § 73.116(c). Likewise, regardless of the acceptability of the lots

from which the vaccine administered to [the plaintiff] were derived, the lots would never have been

produced and released but for the approval of [the]

seed. . . . Thus, the causal connections between the

regulatory violations and plaintiffs’ injuries are

logical, sensible and direct. 

UNITED STATES v. ST. LOUIS UNIVERSITY 17
The government’s argument that the failure to amend the

regulation was not the proximate cause of the plaintiff’s

injuries misconstrues the plaintiff’s claims and the district

court’s opinion. [The government’s] liability arose out of

releasing vaccine in violation of the regulations, not in its

failure to amend the regulations. 

Sabin IV, 984 F.2d at 128 (emphasis added) (citations omitted). 

By this passage, we clearly concluded that the district court’s reasoning — what the majority here terms a merely but-for causation

analysis — constituted a proper proximate cause analysis with respect

to a tortfeasor who functions as a unilateral product-approver. Under

this binding precedent, we are required to conclude that the district

court’s identical reasoning here is likewise a proper proximate cause

analysis. 

The majority’s underlying dissatisfaction with this analysis seems

based on the belief that such an analysis "would result in the government being held strictly liable for its regulatory violations, which

would be inconsistent with Missouri law." Ante at 14. As an initial

matter, strict liability effects culpability standards (e.g., negligence,

recklessness, etc.), not causation standards. That every regulatory violation in the circumstance where the government is a productapprover is the proximate cause of injuries sustained by the use of the

defectively approved product simply does not create strict liability

since under Missouri law it still must be proven that the violation was

the result of negligence or recklessness. 

And, while I am somewhat sympathetic to the majority’s other

apparent concern — that the government is treated differently than the

manufacturer with regards to the causal effect of its action in Callahan’s injury — we may not base our judgment on it, for it is quite

clear that we have already concluded that the district court’s analysis,

distinguishing between the two parties’ causal effects, was proper.

And this determination binds us, regardless of whether our prior reasoning as to why it is so is persuasive. 

The majority’s concern on this score, however, is not even fully

borne out. That the causal effect of the government’s conduct is dif18 UNITED STATES v. ST. LOUIS UNIVERSITY
ferently understood than that of the manufacturer is the result of the

fact that the government’s role as tortfeasor here springs from its

actions as a product-approver. As opposed to a manufacturer, who

presumably sells a range of product, some with and some without

defect, a product-approver’s only role is to determine whether a particular product goes to market at all. In this unique role, failure, and

breach of a duty of care, does not result in any easy comparison

between what would have happened had the defective "product" not

been defective, because, for such a tortfeasor, the defective "product"

is the failure to withhold completely the distributed item from distribution. Thus, had the government’s "product" been free of defect,

none of the offending vaccine would have been distributed at all. This

contrasts with the case of a manufacturer who, had its product been

defect free, would have distributed a defect free product. The causation of injury by one’s "defective" action is quite different from the

other, since one’s "defect-free" action keeps all product from the market while the other instead distributes defect-free product. Since Florida and Maryland law, just like Missouri law, require plaintiffs to

prove proximate cause by demonstrating that, had the product been

defect-free, the injury would not have occurred, and since the government’s defect-free product would have been the complete withholding

of the vaccine, it was not too great of a stretch, even if not wholly persuasive, for us to conclude in Sabin IV that the alleged conduct proximately caused the alleged injury. 

The district court’s notation that its causation analysis took into

account that the government acted under a Good Samaritan duty articulates this aspect of the case. That the majority instead thinks this

notation signals that the lower court mistakenly "believed the causation standard is different in cases where the duty arises under the

Good Samaritan doctrine[,]" ante at 13 (emphasis added), illustrates

the panel’s failure to appreciate how a manufacturer’s defect causes

injury in one way, while defective product approval causes injury in

another. That different causal relationships exist between different

categories of conduct and the injury they cause bespeaks nothing as

to what legal standard applies to those causal relationships in a tort

action. 

But even if there were any merit to the majority’s concerns that our

prior analysis effectively creates a strict liability culpability standard

UNITED STATES v. ST. LOUIS UNIVERSITY 19
or a but-for causation standard and treats the government differently

from the manufacturer, those issues have already been fought over

and decided — and not by today’s opinion. Sabin IV decided the matter and so provides binding reasoning, which, if we were to apply it

today, would result in affirmance of the district court’s judgment.

Indeed, the rule we face not only binds us, but also every district court

within our circuit and every future panel of our court, and the dissent’s judgment only evades that reality temporarily. See Booth v.

Maryland, 327 F.3d 377, 382-83 (4th Cir. 2003) (explaining that it is

error to follow the more recent of two contradicting panels). 

For these reasons, I respectfully dissent.

20 UNITED STATES v. ST. LOUIS UNIVERSITY