FOX et al v. STATE OF MAINE et al

Filing 206

ORDER ON MOTION TO PARTIALLY EXCLUDE EXPERT TESTIMONY OF DR. LAURA BLAISDELL dismissing 171 Motion to Partially Strike Expert Testimony of Dr. Laura Blaisdell By JUDGE JOHN A. WOODCOCK, JR. (CCS)

UNITED STATES DISTRICT COURT
DISTRICT OF MAINE
GREGORY FOX, individually
and as Parent of C.F.,
Plaintiff,
v.
PENDER MAKIN, in her official
capacity as Commissioner, et al.,
Defendants.

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No. 2:22-cv-00251-JAW

ORDER ON MOTION TO PARTIALLY EXCLUDE EXPERT TESTIMONY OF
DR. LAURA BLAISDELL
In advance of summary judgment, a plaintiff in a suit challenging the state of
Maine’s public school vaccination requirements moves to exclude the opinion of a
defendant’s expert pursuant to Federal Rule of Evidence 702. The defendant opposes
exclusion of her expert, arguing her expert’s opinion is supported by reliable
methodology and further that the plaintiff has conflated distinct scientific concepts.
Concluding the defendant’s expert presented a sufficient scientific basis and clearly
distinguished the bounds of her opinions, the court denies the plaintiff’s motion.
I.

PROCEDURAL HISTORY
On July 22, 2022, Dr. Gregory Fox, individually and as parent of C.F., 1 and

Rita Fox, individually and as parent of C.F. (jointly, the Plaintiffs), filed a lawsuit in
the Cumberland County Superior Court for the state of Maine against the state of

The Court refers to Dr. Fox’s minor son by his initials, C.F., in accordance with the Federal
Rule of Civil Procedure 5.2. See FED. R. CIV. P. 5.2(a)(3).

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Maine, the Maine Department of Education, Maine School Administrative District
(MSAD) 51, and various state and local officials (collectively, the Defendants),
alleging the Defendants violated the United States Constitution in promulgating and
implementing a vaccination policy at MSAD 51. Notice of Removal, Attach. 1, Compl.
(ECF No. 1). The Defendants initially identified themselves as forming two groups:
the State Defendants (the state of Maine, the Maine Department of Education, and
Maine Department of Education Commissioner Pender Makin) and the School
Defendants (MSAD 51, MSAD 51 Superintendent Jeffrey Porter, Mabel I. Wilson
Elementary School Principal Sally Loughlin, and Mabel I. Wilson Elementary School
Vice Principal Corey Munsey). Notice of Removal at 1, 3. On August 17, 2022, the
case was removed to this Court. Id.
With the Court’s permission, the Plaintiffs filed an amended complaint on
December 14, 2022 that did not name either the state of Maine or the Maine
Department of Education as defendants and thus left Commissioner Makin and the
School Defendants as the only defendants. Pls.’ Mot. to Am. Compl. (ECF No. 32);
Order (ECF No. 41); Pls.’ Am. Compl. (ECF No. 45).
Next, ruling on motions to dismiss from Commissioner Makin and the School
Defendants, respectively, on August 16, 2023, the Court dismissed all claims against
MSAD 51 and Principal Loughlin, who had retired, and further dismissed all claims
for money damages against Commissioner Makin, Superintendent Porter, and Mr.

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Munsey. 2

Order on Defs.’ Mots. to Dismiss (ECF No. 81). After the Court’s order,

the only surviving claims were against Commissioner Makin, Superintendent Porter,
and Mr. Munsey in their official capacities for declaratory and injunctive relief. 3 Id.
Following the submission of pre-filing memoranda, the Court held a Local Rule
56(h) conference on September 18, 2024, Min. Entry (ECF No. 154), and the next day
issued an order on the conference providing a schedule for the proposed motions for
summary judgment and responses. Order on Local Rule 56(h) Conf. (ECF No. 155)
(Order). At the conference, counsel also raised the possibility that they might file
motions relating to the introduction of expert witness testimony under Daubert v.
Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993), and Kumho Tire Co. v.
Carmichael, 526 U.S. 137 (1999). Id. The Court allowed the parties to confer and
decide whether to file the dispositive and Daubert motions simultaneously or,
alternatively, to file the Daubert motions first. Id.

After Principal Loughlin retired, Mr. Munsey was promoted to principal of Mabel I. Wilson
Elementary School. Order on Defs.’ Mots. to Dismiss at 5 n.7.

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On November 20, 2023, the Plaintiffs moved to amend the amended complaint, seeking to
modify their prayer for relief based on C.F. aging out of Mabel I. Wilson Elementary School and to add
a claim for equitable reimbursement of the expenses paid to educate C.F. Pls.’ Second Mot. to Am.
Compl. (ECF No. 90). On February 22, 2024, a United States Magistrate Judge issued an order and
recommended decision on the second motion to amend complaint, recommending the Court grant the
motion to amend the complaint insofar as it requests placement in the relevant school for the age of
the Plaintiffs’ child at the time of the judgment but deny the motion insofar as it requests equitable
reimbursement. Order and Recommended Decision on Mot. to Am. Compl. at 13 (ECF No. 96). On
July 11, 2024, over the objection of Dr. Fox, the Court affirmed the Magistrate Judge’s recommended
decision. Order on Obj. to Recommended Decision (ECF No. 118). Ms. Fox filed her second amended
complaint on July 14, 2024, and Dr. Fox filed his second amended complaint on August 1, 2024, each
of which incorporated the contents of the first amended complaint with revisions to the prayers for
relief.3 Pl. Rita Fox’s Second Am. Compl. (ECF No. 119); Pl. Gregory Fox’s Second Am. Compl. (ECF
No. 127).

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Commissioner Makin, with the support of the School Defendants, moved to
amend the scheduling order on October 11, 2024, asking the Court to permit filing
and resolution of Daubert motions before summary judgment.

Mot. to Amend

Scheduling Order (ECF No. 158). Dr. Fox responded in opposition to an amendment
to the scheduling order on October 15, 2024. Pl.’s Opp’n to Comm’r Makin’s Mot. to
Amend Schedule ECF 158 (ECF No. 161). Commissioner Makin replied on October
17, 2024 and the School Defendants replied on October 18, 2024. Def. Makin’s Reply
in Support of her Mot. to Amend Scheduling Order (ECF No. 162); School Defs.’ Reply
in Support of Def. Makin’s Mot. to Amend Scheduling Order (ECF No. 164).
On October 21, 2024, the Court granted Commissioner Makin’s motion to
amend scheduling order over Dr. Fox’s objection, staying the deadlines for the filing
of motions for summary judgment until the Daubert motions are resolved and setting
deadlines for the parties to file Daubert motions, oppositions, and replies. Order on
Mot. to Am. Scheduling Order at 6-7 (ECF No. 165). On October 25, 2024, Dr. Fox,
acting pro se, petitioned the Court to reconsider its order. Pet. to Recons. the Decision
to Reset Deadlines as to the Ct.[’]s Order ECF 165 (ECF No. 167). The Court dismissed
Dr. Fox’s motion for reconsideration on November 4, 2024. Order on Pet. to Recons.
(ECF No. 168).
On November 8, 2024, in accordance with the deadlines set in the Court’s order
on motion to amend scheduling order, Dr. Fox moved on Daubert grounds to exclude
certain testimony by Commissioner Makin’s expert witness, Dr. Laura Blaisdell, and

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requested a hearing on the issue. 4 Pl.’s Mot. to Partially Strike Expert Testimony of
Dr. Laura Blaisdell[;] Pl.’s Mot. for Oral Hr’g on Mot. to Strike (ECF No. 170) (Pl.’s
Mot.); Additional Attachs. (ECF No. 172). Commissioner Makin and the School
Defendants each responded in opposition to Dr. Fox’s motion on December 6, 2024.
Def. Pender Makin’s Resp. to Pl. Gregory Fox’s Mot. to Partially Strike Expert
Testimony of Dr. Laura Blaisdell (ECF No. 177) (Makin’s Opp’n); School Defs.’ [Resp.]
to Pl.’s Mot. to Partially Strike Expert Testimony of Dr. Laura Blaisdell and Mot. for
Oral Hearing on Mot. to Strike (ECF No. 178) (School Defs.’ Opp’n). Dr. Fox replied
in support of his motion on December 21, 2024. Pl.[] Gregory Fox’s Reply in Partial
Mot. to Strike Testimony of Laura Blaisdell (ECF No. 189) (Pl.’s Reply).
The Court issues this order to address Dr. Fox’s motion to partially exclude the
expert testimony of Dr. Blaisdell.
II.

THE PARTIES’ POSITIONS
A.

Dr. Fox’s Motion to Exclude Testimony

Dr. Fox moves to exclude certain opinions proffered by Defendant’s expert, Dr.
Blaisdell, arguing “they are based on unreliable data, insufficient facts, and
unsupported methodologies without foundation relevant to the claims at issue.” Pl.’s
Mot. at 1.

Specifically, Dr. Fox asserts Dr. Blaisdell applied an erroneous

methodology to reach her conclusion “regarding the necessary threshold of protection

Dr. Fox calls his motion “a motion to partially strike” select portions of Dr. Blaisdell’s
testimony. Based on his articulated goal of precluding introduction of Dr. Blaisdell’s expert opinion
regarding the public health goal of 95% vaccination rate threshold in schools and references to Federal
Rule of Evidence 702, Daubert, 509 U.S. 579, and Kumho Tire Co., 526 U.S. 137, the Court understands
Dr. Fox’s motion as a motion to exclude expert testimony and recharacterizes it as such.

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in a partially vaccinated population” because her chosen methodology contemplated
a “‘totally susceptible’ population” despite the relevant population being more than
93.5% vaccinated.

Id. at 2.

On these grounds, Dr. Fox insists Dr. Blaisdell’s

methodology was not relevant to the facts of the case. Id. at 3.
Dr. Fox elaborates that Dr. Blaisdell erred “when she inferred a 95%
vaccination rate threshold was necessary to protect susceptible individuals or stop
the transmission of disease,” which he asserts is the foundation of Defendants’
purported compelling state interest in its regulation. Id. Dr. Fox emphasizes that
Dr. Blaisdell relied on others to calculate herd immunity rather than doing so herself,
and claims “it’s more than troubling” that Dr. Blaisdell applied a “totally susceptible”
population methodology that has only one variable—the R0, pronounced R-naught–
despite her awareness of multiple alternative mathematical models to calculate a
herd immunity threshold of protection. Id. at 4. Dr. Fox accepts the accuracy of Dr.
Blaisdell’s methodology if applied to a “totally susceptible” population but urges the
Court to conclude her opinion is unreliable as applied to the facts of this case. Id. He
proffers that, when given the opportunity during her deposition, Dr. Blaisdell “was
unwilling to provide any methodology” for the vaccine threshold for a partially
vaccinated population. Id. at 4-5 (citing id., Attach 6, Video Dep. of Dr. Laura
Blaisdell at 146:22-148:7 (Blaisdell Dep. Tr.)).
Dr. Fox continues that Commissioner Makin’s counsel, Assistant Attorney
General (AAG) Kimberly L. Patwardhan, also recognized the “[l]imits of Dr.
Blaisdell’s reliable scientific expertise” during her deposition through her statement:

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This is beyond the scope of Dr. Blaisdell’s expert report. She already
said she never calculated a herd immunity threshold. She relied on
various other sources that she has identified to you in forming her public
health expert opinion. It is beyond the scope of this expert deposition
and beyond her testimony to inquire about whether or not she has done
particular calculations. She has already testified that she hasn’t done
that.
Id. at 5 (citing Blaisdell Dep. Tr. at 140:4-19). Dr. Fox also claims that, in so stating,
AAG Patwardhan “sought to disrupt the testimony and limit relevant material facts
from entering the record.” Id. at 6.
The Plaintiff argues, despite the accuracy of Dr. Blaisdell’s methodology to a
totally susceptible population, that the expert’s failure to consider alternate
methodologies “does not explain the observable ‘drift’ in expert opinion from central
topic of herd immunity and scientific methodology to ‘generally acceptable
vaccination goal.’” Id. at 7. Dr. Fox asserts the expert provided no methodology to
support the 95% vaccination goal as an “accepted public health goal and standard to
ensure prevention of school outbreaks.” Id. at 7-8 (citing Additional Attachs., Attach.
4, Expert Rep. of Dr. Laura Blaisdell, M.D., M.P.H., F.A.A.P. at 4 (Blaisdell Rep.)).
Dr. Fox argues Dr. Blaisdell’s opinion regarding the “1) required or 2) theorized
quantitative vaccination threshold as a basis is the inadmissible element of Dr.
Blaisdell’s opinion.” Id. at 8 (emphasis removed).
Dr. Fox also asserts he “may use the admissible portion of Dr. Blaisdell’s expert
testimony as part of [his] argument to undermine the Defendant’s position or to
establish the defendant has failed to meet it[]s burden of proof,” claiming Dr.
Blaisdell’s status as Defendant’s expert witness makes her “an agent of the
defendant” and thus her testimony “may be regarded as a party admission” pursuant
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to Federal Rule of Evidence 801. Id. at 8-9 (citing, e.g., FED. R. EVID. 801(d)(2))
(emphasis removed). He insists Dr. Blaisdell’s statements, while not admissible as
fact, may be presented either as Rule 801(d)(2) admissions, which are not subject to
Rule 702 or the Daubert standard, or under the “principle of agency.” Id. at 9.
Dr. Fox next alleges that the Defendants have provided no data to suggest nonreligious exemptions to vaccination requirements pose a lesser risk of disease
transmission and argues the state of Maine cannot “assume ‘the best’ of individuals
engaged in their secular lives while assuming ‘the worst’ about the habits of religious
persons.” Id. at 9 (citing Roberts v. Neace, 958 F.3d 409, 414 (6th Cir. 2020) (citation
amended)).

Dr. Fox emphasizes that, when asked about the comparability of

transmission during her deposition, Dr. Blaisdell answered “the risk of transmission
is unknowable.” Id. at 10 (citing Blaisdell Dep. Tr. at 24:4-5, 15-23).
Finally, Plaintiff directs the Court to additional exhibits which he argues
“contradict [the] unsound methodology posed by Dr. Blaisdell.” Id. He focuses on her
statement:
Immunization rates that are greater than 95% are the generally
accepted public health goal and standard to ensure prevention of
outbreaks . . . This experience is illustrated in Maine between 2011 and
2019 when vaccine preventable disease (VPD) outbreaks occurred
during a time when school vaccine rates dropped. Pertussis (i.e.
whooping cough) outbreaks struck at least 11 schools in Cumberland,
Hancock, Lincoln, and York counties during this time.” Id. (citing
Blaisdell Rep. at 6-7). Dr. Fox points out that 78% of Pertussis cases
were those with up-to-date vaccines in 2018, while in 2019 64% of
Pertussis cases were vaccinated individuals.
Id. at 10-11 (citing id., Attach 11, Pertussis: Me. Surveillance Rep. 2018 ; id., Attach.
12, Pertussis: Me. Surveillance Rep. 2019). Furthermore, Plaintiff says, “Dr. Blaisdell
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has offered no research supporting her statements of Pertussis and prevalence or
incidence during the 2011-2019 years, nor any research methodology disclosed, no
epidemiology study or cited results of data.” Id. at 11.
Dr. Fox concludes that the Court should exclude Dr. Blaisdell’s opinion
regarding a generally accepted 95% vaccination goal as unreliable in the context of
the facts of the present case. Id. at 11.
B.

Commissioner Makin’s Opposition 5

Commissioner Makin opposes Dr. Fox’s requested exclusion of Dr. Blaisdell’s
testimony, asserting Plaintiff’s motion “collapses two related, but distinct concepts:
1) biostatistical herd immunity thresholds and 2) public health targets for school
immunization rates.”

Makin’s Opp’n at 1.

Commissioner Makin quotes the

explanation Dr. Blaisdell gives in her expert report:
Because not everyone in a community can be vaccinated, mathematical
models calculate the critical threshold number of people needed to be
vaccinated in a given community for a given communicable disease.
Generally, immunization rates greater than 95% in schools is the
accepted public health goal and standard to ensure prevention of school
outbreaks.
Id. at 2 (quoting Blaisdell Rep. at 4). Commissioner Makin argues that “[a]lthough
these two sentences are sequential, they address separate concepts.” Id. The first
sentence, she says, “addresses herd immunity thresholds, which are disease-specific
calculations that identify ‘the level of population immunity that is necessary for [an]

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The School Defendants also oppose Dr. Fox’s motion to exclude Dr. Blaisdell’s testimony “for
the same reasons set forth in the Response filed on behalf of Commission Pender Makin, ECF 177,
which the School Defendants incorporate by reference pursuant to Fed. R. Civ. P. 10(c).” School Defs.’
Opp’n at 1. As the School Defendants do not independently assert any arguments in opposition to Dr.
Fox’s motion, the Court reviews only Commissioner Makin’s arguments for the purposes of this order.

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infection to be no longer self-sustaining in the population.’” Id. (citing Pl.’s Mot.,
Attach 5, Peter G. Smith, Concepts of herd protection an immunity, 2:2 PROCEDIA IN
VACCINOLOGY 134-39 (2010) (Smith Article) (citation revised); Blaisdell Rep. at 2, 21).
The second sentence, she distinguishes, “identifies public health vaccination goals,
which take into account not only herd immunity thresholds, but also vaccine
effectiveness and geospatial clustering.” Id.
Commissioner Makin argues Dr. Fox’s motion conflates these two concepts by
presuming the 95% vaccination goal equates to a herd immunity threshold. Id. at 23. She responds to Dr. Fox’s positions that the 95% goal is scientifically unsupported
and that Dr. Blaisdell erred in calculating a herd immunity threshold based on a
totally susceptible population in turn. Id. at 3. First, Commissioner Makin asserts
herd immunity thresholds are calculated using R0, which varies by disease and
constitutes “the average number of other persons that an infectious person will infect
with an agent in a completely susceptible population.” Id. (citing Blaisdell Dep. Tr.
at 131:22-133:1, 141:2). Commissioner Makin explains, in layman terms:
if the R0 of a particular disease or infection is 12, then one infected
person will, on average, infect 12 other persons because none of those 12
persons are immune to the infectious agent (either by immunization or
prior infection). On the other hand, if the R0 of a disease or infection
were less than 1, then one infected person will, on average, not infect
any other person. Accordingly, the higher the value the R0, the more
infectious the disease.
Id. Commissioner Makin points out that Dr. Fox concedes a disease’s R0 range is
calculated based on natural studies of a “completely susceptible population” and adds
that, due to effective vaccination programs in the United States, the R0 of certain
diseases are unknowable and likely higher than the generally accepted ranges. Id.
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at 3-4 (citing id., Attach. 1, Decl. of Laura Lilienthal Blaisdell, M.D. ¶ 11 (Blaisdell
Decl.)).
Herd immunity thresholds, Commissioner Makin says, rely on a disease’s R0
to conduct a further calculation, through multiple mathematical models, of the level
of population immunity required for disease elimination. Id. at 4. “Dr. Blaisdell
generally relies on other experts for calculations of R0 and herd immunity thresholds
in forming her public health opinions.” Id. (citing Blaisdell Dep. Tr. 134:17-20).
However, Commissioner Makin says, R0 is the basis of “every herd immunity
threshold calculation.” Id. (Defendant’s emphasis). Commissioner Makin claims Dr.
Fox “is conflating R0, i.e., the basic reproductive number, with R, i.e., the effective
reproductive number, which considers the proportion of a population that is immune
to a particular disease or infection” and that the herd immunity threshold remains
constant regardless of the R for a given population because it is the calculation that
reduces R to less than one, signifying when an infected person will infect less than
one other person on average. Id. (citing Smith Article at 3; Blaisdell Decl. ¶ 13)
(Defendant’s emphasis).

Commissioner Makin insists medical literature has

generally understood and accepted that a herd immunity threshold is calculated
based on R0, not R. Id. at 4-5 (citing Blaisdell Decl. ¶ 14; Ruiz-Troche v. Pepsi Cola
of P.R. Bottling Co., 161 F.3d 77, 84 (1st Cir. 1998)).
Turning to her second argument, Commissioner Makin submits that, while
herd immunity thresholds are used to determine school vaccination goals, the two are
distinct and calculated through different methodologies and Dr. Fox has presumed

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that the herd immunity threshold calculation “equated to the 95% public health
vaccination goal.” Id. at 5. She points out that Dr. Blaisdell distinguished the two as
“distinctly different” in her deposition and that Dr. Fox “failed to fully explore the
methodology” that gave rise to the 95% vaccination goal. Id. (citing Blaisdell Dep. Tr.
at 155:25-158:7, 166:9-167:4).
Commissioner Makin explains further that the 95% public health school
vaccination goal is based on the herd immunity threshold for a particular disease, but
also acknowledges the risk that a generally accepted R0 for a particular disease is
understated, that vaccines are not 100% effective or always available, and the
geospatial clustering of susceptible individuals in schools. Id. at 5-6 (citing Blaisdell
Decl. ¶¶ 11, 15-20). To account for these factors, Commissioner Makin submits, the
rate of vaccination coverage must be higher than the herd immunity threshold,
resulting in Dr. Blaisdell’s conclusion that “immunization rates greater than 95% in
schools is the accepted public health goal and standard to ensure prevention of school
outbreaks.” Id. at 6 (quoting Blaisdell Rep. at 2). The 95% immunization rate goal
is supported by the United States Centers for Disease Control and Prevention (U.S.
CDC) and the Maine Center for Disease Control and Prevention (Maine CDC), as well
as by data regarding vaccine-preventable diseases in Maine. Id. (citing Blaisdell Rep.
at 6-7).
Finally, Commissioner Makin argues Dr. Fox errs by challenging the data
underlying Dr. Blaisdell’s report based on individual cases, rather than outbreaks,
and adds that challenges to the factual basis of an expert opinion goes to credibility,

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not admissibility, and should be developed during cross-examination. Id. (citing
Brown v. Wal-Mart Stores, Inc., 402 F. Supp. 2d 303, 308 (D. Me. 2005) (quoting
Larson v. Kempker, 414 F.3d 936, 941 (8th Cir.2005) (quotations and citations
omitted)). Thus, Commissioner Makin concludes, the Court should deny Dr. Fox’s
motion. Id. at 7.
C.

Dr. Fox’s Reply

Dr. Fox replies in support of his motion to exclude Dr. Blaisdell’s expert
opinion, arguing Commissioner Makin’s arguments that public health goals
governing the necessity of vaccines are “subject to both the effectiveness of the vaccine
and coverage rates” were raised for the first time in her response. Pl.’s Reply at 1.
Plaintiff submits Dr. Blaisdell’s declaration that vaccines are not 100% effective is an
expansion of her expert testimony and fails to explain the difference in risk posed by
a student recipient of an ineffective vaccine and a student with a religious exemption.
Id. at 2. Dr. Fox points out Dr. Blaisdell opines non-medical exemptions pose a risk
to herd immunity but does not offer a similar opinion regarding the increased risk of
the ineffective vaccine nor explain why ineffectiveness poses less risk than
unvaccinated individuals. Id. at 2-3 (citing Blaisdell Rep.). He emphasizes Dr.
Blaisdell’s opinion fails to explain how vaccine effectiveness affects determinations of
geospatial clustering or population susceptibility and posits that Dr. Blaisdell’s
assertion regarding vaccine effectiveness in fact serves to undercut Commissioner
Makin’s reasoning for removing religious exemptions to vaccination requirements.
Id. at 3-4.

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Dr. Fox argues Dr. Blaisdell’s declaration serves as an admission that her
report is unreliable and seeks to add additional testimony via declaration to buttress
her conclusions without providing the Plaintiff with an opportunity to cross-examine
her on the new information, as the discovery period closed on July 18, 2024. Id. (citing
LaPlace-Bayard v. Batlle, 295 F.3d 157 (1st Cir. 2002)). He also asserts Dr. Blaisdell
refers to “outbreaks” by erroneously blending state levels of infection, which are not
specific to schools, and vaccine coverage rates in schools. Id. at 4.
Plaintiff contends Dr. Blaisdell’s opinion failed to consider vaccine
effectiveness, was not based on accepted methods of assessing comparability of risk,
and did not discuss rates of error, such that her testimony is conclusory and
unsupported by the scientific record. Id. He continues that Commissioner Makin’s
citations to other public health agencies that have accepted the goal of a 95%
vaccination rate are unpersuasive because she does not address why other states
maintain religious exemptions to school vaccines. Id. at 5.
III.

LEGAL STANDARD
The admissibility of expert testimony is a question of law governed by Federal

Rule of Evidence 702 and by the United States Supreme Court’s rulings in Daubert,
509 U.S. 579, Kumho, 526 U.S. 137, and their progeny. Rule 702 provides:
A witness who is qualified as an expert by knowledge, skill,
experience, training, or education may testify in the form of an
opinion or otherwise if:
(a) the expert’s scientific, technical, or otherwise specialized
knowledge will help the trier of fact to understand the evidence
or to determine a fact in issue;
(b) the testimony is based on sufficient facts or data;
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(c) the testimony is the product of reliable principles and methods;
and
(d) the expert has reliably applied the principles and methods to
the facts of the case.
FED. R. EVID. 702. The First Circuit has “long entrusted federal trial judges to be
‘gate-keeper[s],’ empowered by Rule 702 and Daubert to ‘ensure that an expert’s
testimony “both rests on a reliable foundation and is relevant to the task at
hand.”’” United States v. Vargas, 471 F.3d 255, 261 (1st Cir. 2006) (quoting Daubert,
509 U.S. at 597).
In general, “[e]xpert testimony is admissible if ‘scientific, technical, or other
specialized knowledge will assist the trier of fact to understand the evidence or to
determine a fact in issue’ and if the proposed witness is qualified as an expert by some
specialized ‘knowledge, skill, experience, training, or education.’” Liberty Mut. Ins.
Co. v. Broan-NuTone LLC, No. 21-cv-11986-DLC, 2024 U.S. Dist. LEXIS 76408, at
*5-6 (D. Mass. Apr. 26, 2024) (quoting Daubert, 509 U.S. at 588). “A district court
may exclude expert testimony where it finds that the testimony has no foundation or
rests on . . . speculative evidence.” Schubert v. Nissan Motor Corp. in U.S.A., 148
F.3d 25, 29-30 (1st Cir. 1998) (quoting Casas Office Machs., Inc. v. Mita Copystar Am.,
Inc., 42 F.3d 668, 681 (1st Cir. 1994)); accord Gonzalez-Arroyo v. Drs.’ Ctr. Hosp.
Bayamon, Inc., 54 F.4th 7, 14 (1st Cir. 2022) (“to provide admissible testimony, an
expert must render conclusions ‘in a scientifically sound and methodologically
reliable fashion’”) (quoting Milward v. Acuity Specialty Prods. Grp., Inc. (Milward I),
639 F.3d 11, 15 (1st Cir. 2011))).

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“Neither Daubert nor Rule 702 permits expert opinions grounded only in the
unsupported assertions of the expert.” Gonzalez-Arroyo, 54 F.4th at 14 (citing LópezRamírez v. Toledo-González, 32 F.4th 87, 94 (1st Cir. 2022)). “[T]he overarching
concern is on the ‘evidentiary relevance and reliability’ of the proposed testimony,”
with speculative expert testimony often satisfying neither criterion. Seahorse Marine
Supplies, Inc. v. P.R. Sun Oil Co., 295 F.3d 68, 81 (1st Cir. 2002) (quoting Daubert,
509 U.S. at 595). Should a court determine an expert opinion is unsupported, the
First Circuit directs “a court may conclude that there is simply too great an analytical
gap between the data and the opinion proffered, provided that gap is not of the district
court’s making.” Gonzalez-Arroyo, 54 F.4th at 14 (citing López-Ramírez, 32 F.4th at
94) (internal citations and quotation marks omitted)).
Exclusion of proposed expert witnesses often occurs in the run-up to trial;
however, the First Circuit has clarified that the same standard applies to motions
brought at the summary judgment stage. Samaan v. St. Joseph Hosp., 670 F.3d 21,
32 (1st Cir. 2012) (“a Daubert hearing appropriately may be held at the summary
judgment stage”) (citing Cortes-Irizarry v. Corp. Insular De Seguros, 111 F.3d 184,
188 (1st Cir. 1997)); accord Alt. Sys. Concepts, Inc. v. Synopsys, Inc., 374 F.3d 23, 3132 (1st Cir. 2004) (“Evidentiary rulings have the potential to shape and winnow the
scope of the summary judgment inquiry, and a trial court should have as much leeway
in dealing with those matters at the summary judgment stage as at trial”). However,
on summary judgment, “courts must be cautious -- except when defects are obvious
on the face of a proffer -- not to exclude debatable scientific evidence without affording

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the proponent of the evidence adequate opportunity to defend its admissibility.”
Cortes-Irizarry, 111 F.3d at 188.
IV.

DISCUSSION
Dr. Fox does not generally dispute Dr. Blaisdell’s qualifications as an expert

witness, a wise decision in light of her multiple advanced degrees in medicine and
public health, longstanding board-certification as a pediatrician, and academic
experience as an educator with a focus on vaccination and infectious diseases. See
Blaisdell Rep. at 2. Rather, Dr. Fox focuses specifically on Dr. Blaisdell’s opinion
regarding a target 95% vaccination rate, which he complains is unreliable and
unsupported by a scientific methodology as applied to the facts of the case based on
Dr Blaisdell’s erroneous presumption of a “totally susceptible” population, as
demonstrated through her use of the variable R0. Pl.’s Mot. at 6-8. Commissioner
Makin responds that Dr. Fox conflates herd immunity threshold rates with public
health targets for vaccination rates in schools, and further that Dr. Blaisdell’s use of
R0 to determine the relevant herd immunity threshold is a generally accepted
practice. Makin’s Opp’n at 1-5.
The Court first considers whether Dr. Blaisdell has provided sufficient support
for her methodology of using R0 to calculate a herd immunity threshold. Two of the
scientific articles cited by Dr. Blaisdell in her report apply R0 as the basis for
calculating herd immunity thresholds. Blaisdell Decl. ¶ 14 (citing Makin’s Opp’n,
Attach. 3, Paul Fine, et al., “Herd Immunity”: A Rough Guide, 52:7 CLINICAL
INFECTIOUS DISEASES 911-16 (2011); id., Attach. 4, Pedro Plans-Rubió, Evaluation of

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the establishment of herd immunity in the population by means of serological surveys
and vaccination coverage, 8:2 HUM. VACCINES & IMMUNOTHERAPEUTICS 184-88
(2012)). Further, as pointed out by Commissioner Makin, Concepts of herd protection
and immunity, the article cited by Dr. Fox in support of his motion, also uses the R0
of particular diseases to calculate their respective herd immunity thresholds. See
Smith Article at 3.
While the use of this methodology in other scientific literature is not dispositive
as to its reliability, the First Circuit has held that “publication and peer review also
demonstrate a measure of acceptance of the methodology within the scientific
community.” Ruiz-Troche, 16 F.3d at 84; see also id. at 85 (“While the literature does
not irrefutably prove the accuracy of [the expert’s] conclusions, it furnishes a
sufficient underpinning for those conclusions to forfend preclusion of his testimony
as unreliable”). Notably, Dr. Fox himself concedes the accuracy of the R0 methodology
to calculating herd immunity thresholds for “totally susceptible” populations but
argues this calculus is inapposite here, where the population is only “partially
susceptible.”

Pl.’s Mot. at 4-5.

Dr. Fox may seek to undermine the factual

underpinnings of Dr. Blaisdell’s use of R0 based on this basis, but these criticisms go
toward the weight and credibility of her testimony, rather than admissibility.
Kirouac v. Donahoe, No. 2:11-cv-00423-JAW, 2013 U.S. Dist. LEXIS 6331, at *5-6 (D.
Me. Jan. 16, 2013) (“If the factual underpinnings of [the expert’s] opinions [are] in
fact weak, that [is] a matter affecting the weight and credibility of [the experts’]
testimony”) (quoting Payton v. Abbott Labs., 780 F.2d 147, 156 (1st Cir.1985)). The

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Court thus concludes Dr. Blaisdell’s use of R0 to calculate herd immunity thresholds
does not disqualify her expert opinion as inherently unreliable.
Continuing to Dr. Fox’s claim that Dr. Blaisdell’s asserted goal of 95%
vaccination coverage lacks scientific support, Dr. Fox argues Dr. Blaisdell erred
“when she inferred a 95% vaccination rate threshold was necessary to protect
susceptible individuals or stop the transmission of disease.”

Pl.’s Mot. at 3.

Commissioner Makin responds that Dr. Fox conflates the herd immunity threshold
with the public health goal for vaccination in schools. Makin’s Opp’n. at 2-3, 5-6.
Dr. Blaisdell’s expert report states: “[g]enerally, immunization rates greater
than 95% in schools is the accepted public health goal and standard to ensure
prevention of school outbreaks.” Blaisdell Rep. at 4. In support, she cites Renee
Seither, et al., Coverage with Selected Vaccines and Exemption Rates Among Children
in Kindergarten - United States, 2023-24 School Year, 73:41 MORBIDITY & MORTALITY
WKLY REP. 925-932 (2024) (Seither Article), which discusses a target of 95%
vaccination coverage for measles, mumps, and rubella (MMR) in kindergarten age
children. Id. (citing Seither Article at 929). Dr. Blaisdell’s report also discusses
anecdotal evidence of outbreaks of Pertussis at Maine schools in 2018, which
corresponded with vaccination rates of kindergarten students declining below the
target 95% threshold from 2011 to 2019. Id. at 6-7 (citing e.g., Safer Schools Through
Community Immunity, ME. IMMUNIZATION COALITION; Me. Monthly Pertussis
Surveillance Rep. Dec. 2019, ME. DEP’T OF HEALTH AND HUM. SERVS.). Commissioner
Makin adds that the 95% vaccination coverage public health goal aligns with targets

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articulated by the U.S. CDC and Maine CDC. Makin’s Opp’n at 6 (citing U.S. CDC,
CDC Call to Action: What Schools Can Do to Promote Routine Vaccination Catch-Up
Among School Aged Children (noting “target of 95% routine kindergarten vaccination
coverage by ensuring all kindergarteners without a documented exemption are
vaccinated”); Maine CDC, 2023-24 Me. Immunization Assessment Rep. (stating goal
of “the Maine Immunization Program to bring the State vaccine coverage rate
average for each of these vaccines to 100%”)).
At deposition, Dr. Blaisdell clearly distinguished herd immunity thresholds
from public health goals for vaccination coverage in schools:
[Dr. Blaisdell]. You keep referencing this 95 percent. That is a public
health recommendation for vaccination levels.
[Dr. Fox]. Okay.
[Dr. Blaisdell]. And you seem to confuse it with herd immunity
thresholds. And so I want to be very clear that a 95 percent vaccination
rate for any particular vaccine is a public health recommendation.
[Dr. Fox]. Is it a threshold, or is it a -- it is a –
[Dr. Blaisdell]. That is not a herd immunity threshold.
[Dr. Fox]. 95 percent is not?
[Dr. Blaisdell]. It is a -- in my expert testimony I have said that that is
the -- the -- I will read. “Generally, immunization rates greater than 95
percent in schools is the accepted public health goal and standard to
ensure prevention of school outbreaks.” That is distinctly different, Dr.
Fox, than a herd immunity threshold for which we’ve had this
conversation about calculations -- very scientific and detailed
calculations for which I rely on other experts to give me that data.
Blaisdell Dep. Tr. at 155-25-156:21. In her declaration, Dr. Blaisdell further explains
the basis for the difference; while herd immunity threshold is a factor in the public
health goals, so too are the facts that an accepted R0 for a particular disease may be
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understated, that vaccines are not 100% effective or always available, and the
geospatial clustering of susceptible individuals in schools, all of which lead to the
public health goal for vaccination being higher than the herd immunity threshold.
Blaisdell Decl. ¶ 15-20.
Dr. Fox takes issue with the fact that Commissioner Makin, through Dr.
Blaisdell, raises vaccine efficacy arguments for the first time in her opposition to his
motion to exclude Dr. Blaisdell’s testimony. Pl.’s Reply at 4. However, the First
Circuit is clear that, before excluding expert opinion at the summary judgment stage,
a court should permit the proponent of the evidence to defend its admissibility.
Cortes-Irizarry, 111 F.3d at 188. By the Court’s read, the Defendant did just that.
Dr. Fox further complains Dr. Blaisdell fails to compare risks related to vaccine
efficacy to risks stemming from religious-based exemptions to vaccinations. Pl.’s
Reply at 2-3. Dr. Fox may seek to undermine the credibility and weight of the 95%
vaccination coverage goal with this argument, but Daubert does not require a party
to prove an expert’s assessment is correct, just that it “rests upon ‘good grounds, based
on what is known.’” Ruiz-Troche, 161 F.3d at 85 (quoting Daubert, 509 U.S. at 590);
see also Kirouac, 2013 U.S. Dist. LEXIS 6331, at *5-6 (“If the factual underpinnings
of [the expert’s] opinions [are] in fact weak, that [is] a matter affecting the weight and
credibility of [the expert’s] testimony”) (quoting Payton, 780 F.2d at 156).

The

Defendant’s expert has met this bar.
Based on her cited scientific sources and articulated methodology, the Court
concludes Dr. Blaisdell has distinguished herd immunity threshold calculations from

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the public health goal of 95% vaccination coverage and has provided sufficient
evidentiary support for the Court to admit her expert opinion that 95% is a commonly
accepted goal for vaccination coverage in schools. 6
V.

CONCLUSION
The Court DISMISSES without prejudice Gregory Fox’s Motion to Partially

Strike Expert Testimony of Dr. Laura Blaisdell and Motion for Oral Hearing on
Motion to Strike (ECF No. 171).
SO ORDERED.
/s/ John A. Woodcock, Jr.
JOHN A. WOODCOCK, JR.
UNITED STATES DISTRICT JUDGE
Dated this 10th day of March, 2025

The Court further considered Dr. Fox’s request for oral argument on his motion to exclude the
testimony of Dr. Blaisdell. Pl.’s Mot. at 1. As the Court concluded it could properly resolve the motion
based on the parties’ written submissions, an oral argument would only delay the resolution of the
motion and the Court thus declines to schedule oral argument.

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