For more information: www.cdc.gov/COVID19

COVID-19 vaccines:

Work Group interpretations 

ACIP COVID-19 Vaccines Work Group

Sara Oliver MD, MSPH

ACIP Meeting

August 26, 2020
COVID-19 vaccines in human clinical trials 
COVID-19 vaccines in human clinical trials – United States*

*As of August 22, 2020. Trials listed as actively recruiting on clinicaltrials.gov 

Sources: https://milkeninstitute.org/covid-19-tracker; https://www.who.int/who-documents-detail/draft-landscape-of-covid-19-candidate-vaccines; 

https://vac-lshtm.shinyapps.io/ncov_vaccine_landscape/

Candidate Manufacturer Type Phase Trial characteristics Trial #s

mRNA-1273 Moderna TX, Inc. mRNA III • 2 doses (0, 28d)

• IM administration

• 18-55, 56+ years

NCT04283461 (II)

NCT04405076 (II)

NCT04470427 (III)

mRNA-BNT162 Pfizer, Inc./BioNTech mRNA I/II/III • Single or 2 doses

• IM administration

• 18-85 years

NCT04368728

EudraCT 2020-001038-36

ChiCTR2000034825

INO-4800 Inovio Pharmaceuticals, 

Inc.

DNA 

plasmid

I/II • 2 doses (0, 4w)

• SC administration/ 

electroporation

• ≥18 years

NCT04336410 (I)

NCT04447781

Ad26COVS1 Janssen Pharmaceutical 

Companies

NonReplicating

Viral Vector

I/II • 2 doses (0,56d)

• IM administration

• 18-55, 65+

NCT04436276

3
COVID-19 vaccines in human clinical trials – outside United States*

mRNA/DNA vaccines

Candidate Manufacturer Type Trial Location Phase Trial #

CVnCoV CureVac mRNA Belgium, Germany I/II NCT04449276, 

NCT04515147

-- People’s Liberation Army Acad. Med. 

Sciences

mRNA China I ChiCTR2000034112

-- Arcturus/Duke-NUS mRNA Singapore I/II NCT04480957

LNPnCoVsaRNAImperial College London saRNA U.K. I ISRCTN17072692

GX-19 Genexine Consortium DNA South Korea I/II NCT04445389

-- Osaka University/AnGes DNA 

plasmid+adjuvant

Japan I/II NCT04463472

-- Cadila Healthcare Limited DNA plasmid India I/II CTRI/2020/07/026352 

*As of August 22, 2020. Trials listed as actively recruiting on clinicaltrials.gov 

Sources: https://milkeninstitute.org/covid-19-tracker; https://www.who.int/who-documents-detail/draft-landscape-of-covid-19-candidate-vaccines; 

https://vac-lshtm.shinyapps.io/ncov_vaccine_landscape/ 4
COVID-19 vaccines in human clinical trials – outside United States*

Protein subunit vaccines

Candidate Manufacturer Type Trial Location Phase Trial #

NVXCoV2373Novavax Protein subunit Australia I/II NCT04368988

-- Anhui Zhifei Longcom/

Chinese Academy of Science

Protein subunit China II NCT04445194, NCT04466085

SCB-2019 Clover/GSK/Dynavax Protein subunit Australia I NCT04405908

Covax-19 Vaxine Protein subunit Australia I NCT04453852

-- University of Queensland/CSL/Seqirus Protein subunit Australia I ACTRN12620000674932p

-- Instituto Finlay de Vacunas Protein subunit Cuba I/II RPCEC00000332

*As of August 22, 2020. Trials listed as actively recruiting on clinicaltrials.gov 

Sources: https://milkeninstitute.org/covid-19-tracker; https://www.who.int/who-documents-detail/draft-landscape-of-covid-19-candidate-vaccines; 

https://vac-lshtm.shinyapps.io/ncov_vaccine_landscape/ 5
Candidate Manufacturer Type Trial Location Phase Trial #

-- Medicago VLP Canada I NCT04450004

ad5-nCov CanSino Biologics, Inc. Viral vector (NR) China II* NCT04313127, 

NCT04398147, NCT04341389

AZD1222 University of Oxford/AstraZeneca consortium Viral vector (NR) UK, South Africa, 

Brazil

II/III NCT04324606, NCT04400838

EudraCT 2020-001072-15, 

EudraCT 2020-001228-32

aAPC Shenzhen Geno-Immune Medical Institute Viral vector China I NCT04299724

LV-SMENP-DC Shenzhen Geno-Immune Medical Institute Viral vector China I NCT04276896

Ad26COVS1 Janssen Viral Vector (NR) Belgium I/II NCT04436276, NCT04505722

Gam-COVIDVacGamaleya Research Institute Viral vector (NR) Russia I NCT04437875, NCT04436471

-- Institut Pasteur/ Themis/ University of 

Pittsburgh CVR/ Merck Sharp & Dohme

Viral vector France, Belgium I NCT04497298

COVID-19 vaccines in human clinical trials – outside United States*

Viral Vector vaccines

*As of August 22, 2020. Trials listed as actively recruiting on clinicaltrials.gov 

Sources: https://milkeninstitute.org/covid-19-tracker; https://www.who.int/who-documents-detail/draft-landscape-of-covid-19-candidate-vaccines; 

https://vac-lshtm.shinyapps.io/ncov_vaccine_landscape/ 6
COVID-19 vaccines in human clinical trials – outside United States*

Inactivated vaccines

*As of August 22, 2020. Trials listed as actively recruiting on clinicaltrials.gov 

Sources: https://milkeninstitute.org/covid-19-tracker; https://www.who.int/who-documents-detail/draft-landscape-of-covid-19-candidate-vaccines; 

https://vac-lshtm.shinyapps.io/ncov_vaccine_landscape/

Candidate Manufacturer Type Trial Location Phase Trial #

BBIBP-CorV Beijing Institute of Biological 

Products/Sinopharm

Inactivated China III ChiCTR2000032459

ChiCTR2000034780

-- Wuhan Institute of Biological 

Products/Sinopharm

Inactivated China, UAE III ChiCTR2000031809

ChiCTR2000034780

CoronaVac Sinovac/Instituto Butantan Inactivated China, Brazil III NCT04352608, 

NCT04383574, 

NCT04456595

-- Inst. of Med. Biology/Chinese Acad. Med. 

Sciences

Inactivated China II NCT04412538, 

NCT04470609

BBV152 Bharat Biotech Inactivated India I/II CTRI/2020/07/026300,

NCT04471519

7
Work Group Interpretation: 

Clinical Trial Data
 Phase I Immunogenicity data from 2 COVID-19 mRNA vaccines 

 Phase I Safety data from 2 COVID-19 mRNA vaccines

 Overview/Plans for Phase II/III studies for 2 COVID-19 mRNA vaccines 

Information Reviewed by Work Group 

9
 Immunogenicity 

– Neutralizing antibodies (pseudovirus neutralization assay titers) and binding 

antibodies (ELISA) measured 7 days post-dose 2 

– Responses similar to or exceeded convalescent sera comparison

– Th1-biased CD4+ T-cell response 

– 100μg dose selected for Phase III clinical trials

 Safety

– Local and systemic symptoms followed for 7 days post-vaccination

• Pain, myalgia, fatigue most common symptoms reported 

– Reactogenicity symptoms higher after second dose 

– No vaccine-related serious adverse events (SAEs) reported 

Immunogenicity and Safety Information Reviewed by Work Group

mRNA1273 (Moderna) N=130 

10
 Immunogenicity

– Neutralizing antibodies (50% neutralization titers) measured 7 days post-dose 2 

– Responses similar to or exceeded human convalescent panel

– CD4+ and CD8+ T cell response demonstrated

– Th1-biased CD4+ T-cell response 

– 30μg dose of BNT162b2 selected for Phase III clinical trials

 Safety

– Local and systemic symptoms followed after administration

• Fatigue, headache and muscle pain most common

– Reactogenicity symptoms lower in older population (65-85 years) 

Immunogenicity and Safety Information Reviewed by Work Group

BNT162b2 (Pfizer/BioNTech) N=195

11
 Both vaccine candidates currently enrolling large (~30,000 people) Phase III 

efficacy trials

 Primary endpoints: symptomatic, virologically confirmed COVID-19 disease

 Attempting to enroll diverse populations:

– Race and ethnicity

– Age (<65 years and ≥65 years of age)

– Underlying medical conditions 

Plans for Phase III 

12
 Phase I data from both mRNA vaccines show induction of neutralizing 

antibodies at 7 days post-dose 2 that exceed levels in convalescent sera

 Data from both mRNA vaccines support advancing to large scale Phase III 

clinical trials to assess safety and efficacy

 Diverse cold-chain or ultra-low temperature requirements can substantially 

affect implementation efforts

Work Group Interpretation 

13
 Emphasized the importance of enrolling diverse study participants

 Emphasized the need to allow for sufficient time post-dose 2 to evaluate safety signals 

 Need to report maternal and fetal outcomes for women who become pregnant during 

the clinical trials 

 Evaluate vaccine impact on viral shedding or transmission, among symptomatic and 

asymptomatic populations 

Work Group Interpretation: 

Current Phase III Clinical Trials 

14
 Emphasized the importance of enrolling diverse study participants

 Emphasized the need to allow for sufficient time post-dose 2 to evaluate safety signals 

 Need to report maternal and fetal outcomes for women who become pregnant during 

the clinical trials 

 Evaluate vaccine impact on viral shedding or transmission, among symptomatic and 

asymptomatic populations 

15

– Co-administration of other vaccines 

especially influenza vaccine

– Pregnant women

– Children 

Work Group Interpretation: 

Future/Additional Studies

Work Group Interpretation: 

Current Phase III Clinical Trials 
Work Group Interpretation: 

Epidemiology Data
 COVID-19 epidemiology among U.S. population

 Epidemiology among various occupational settings

 Epidemiology among individuals at increased risk of severe COVID-19 disease

Information Reviewed by Work Group 

17
 Healthcare Personnel (HCP) are essential 

workers defined as paid and unpaid persons 

serving in healthcare settings who have the 

potential for direct or indirect exposure to 

patients or infectious materials 

Healthcare Personnel 

18
 Healthcare Personnel Type: N=512

– Respiratory Therapist: 3 (<1%)

– Physician: 23 (5%)

– Nurse: 125 (24%)

– Other: 276 (54%)

– Not specified: 85 (17%)

Healthcare Personnel within COVID-NET

March 1 to July 11, 2020

Hospital-based patient care support

(e.g. nursing assistant) 73

Other patient care 21

Housekeeping/Environmental Services 20

Other nursing home/LTCF staff 17

Technicians 15

Management 12

Home health worker 12

Emergency medical personnel 10

Social work/counselor 10

Pharmacy 9

Food Services 8

Dentistry 6

Laboratory 6

Other 57

19
Cases among Staff at Skilled Nursing Facilities

Count and Incidence per 1,000 Resident Weeks

Data from NHSN LTCF module:

https://data.cms.gov/stories/s/COVID-19-Nursing-Home-Data/bkwz-xpvg/

Long Term Care Facility Workforce

 Disproportionately lower-wage workers

 39% of workers are 50 years of age or older

 82% of workers are female, 26% nonHispanic Black persons

 Staff can be shared among multiple facilities

 In many instances, COVID-19 activity 

increases among LTCF staff first, and then 

residents

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 Among 14 states reporting total number of workers in affected meat and poultry 

processing plants from April–May 2020, COVID-19 diagnosed in 9.1% of workers 

– Among cases with race and ethnicity reported, 87% occurred among racial or ethnic 

minorities

 Outbreaks have been reported in many food production/agriculture sectors

– Multiple factors that increase workers’ risk for exposure to SARS-CoV-2:

• Prolonged close workplace contact with coworkers

• Shared transportation and/or congregate housing

• Lack of paid sick leave

Workers in Food Processing and Agriculture 

21
 Correction and detention staff members can introduce the virus through 

their daily movements between the facility and the community

 In an analysis of 16 U.S. prisons and jails, more than half of the facilities 

identified their first case of COVID-19 among staff members1

Workers in Correction and Detention Facilities

1Hagan et al. MMWR –August 21, 2020 https://www.cdc.gov/mmwr/volumes/69/wr/mm6933a3.htm?s_cid=mm6933a3_w 22
 Accounting for presence of individual underlying medical conditions, higher 

hospitalization rates were observed among adults ≥65 years 

 Higher hospitalization rates observed for adults with underlying medical 

conditions, after accounting for age, race and ethnicity, and sex

– Obesity

– Chronic kidney disease

– Diabetes

– Hypertension

Adults with increased risk for severe COVID-19 disease 

https://medrxiv.org/cgi/content/short/2020.07.27.20161810v1

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 Population model 

– Similar number of infections prevented by vaccinating HCP, essential workers and adults 

with underlying medical conditions 

– Vaccinating older adults resulted in more modest declines in infections and larger declines 

in deaths compared to other groups

– Differences in impact between vaccinating different groups was small 

 Nursing Home model

– More infections and deaths prevented by vaccinating HCP compared to vaccinating NH 

residents

Work Group Interpretation-- Modeling

The more infection we prevent now, the more impact the vaccine will have

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 Many occupations (e.g. “essential workers”) at increased risk of COVID-19 disease

– Important to consider individuals unable to socially distance or work from home

 Older adults and adults with underlying medical conditions also at increased risk 

of COVID-19 disease 

– Many essential workers also older or have an underlying medical conditions 

 In many instances, cases increase first among staff in congregate settings 

(e.g. LTCF or correctional facilities) 

– Possible that some protection could be provided to these vulnerable populations by 

immunity among staff/workers

Work Group Interpretation 

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For more information, contact CDC

1-800-CDC-INFO (232-4636)

TTY: 1-888-232-6348 www.cdc.gov

The findings and conclusions in this report are those of the authors and do not necessarily represent the 

official position of the Centers for Disease Control and Prevention.

Thank you