FOX v. MAKIN

UNITED STATES DISTRICT COURT

DISTRICT OF MAINE

GREGORY FOX, individually )

and as Parent of C.F., )

)

Plaintiff, )

)

v. ) No. 2:22-cv-00251-JAW

)

PENDER MAKIN, in her official )

capacity as Commissioner, et al., )

)

Defendants. )

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

1 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).

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.

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.

2 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.

3 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).

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

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

4 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.

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:

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

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 non-

religious 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

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 Opposition5

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]

5 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.

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 2-

3. 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.

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

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,

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.

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;

(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))).

“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 López-

Ramírez 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, 31-

32 (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

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

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

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

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

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

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

6 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.