Introduction
The number of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cases and
associated death continue to rise globally. Widespread testing for SARS-CoV-2 infection
is crucial in order to identify individuals who need to need to be isolated, thereby
reducing their chances to infect others and allowing them to seek treatment earlier
which can prevent further negative health outcomes and mortality (1). Currently, the
most common testing method for SARS-CoV-2 diagnosis is Real-Time Polymerase Chain
Reaction (RT-PCR) from nasopharyngeal, throat or saliva specimens (2). However, SARS-CoV-2
testing has been hampered in many countries due to inadequate test kits, uncomfortable
testing procedures, shortages of personal protective equipment (PPE) for health care
workers, and low demand among people to seek testing for SARS-CoV-2 at health facilities
(3–7).
In response, the United States Food and Drug Administration (FDA) provided Emergency
Authorization Use for several SARS-CoV-2 self-sampling kits (SARS-CoV-2SS) that allow
individuals to self-collect nasal swabs and saliva specimens and send to a lab for
testing (8). Other efforts to increase testing include drive-through methods that
include both self-sampling and health care- collected samples (9, 10). The National
Institute of Health has also launched the Rapid Acceleration of Diagnostics (RADx)
program to accelerate the development of, scale up, and deploy innovative point-of-care
of technologies, support the scale-up of more advanced technologies, and nontraditional
approaches for testing as well as establish community-engaged implementation projects
to improve access to testing in underserved and vulnerable populations (11). Similar
research and programmatic activities to increase testing capacity SARS-CoV-2 are also
being implemented in other regions (12–16).
The efforts to increase testing capacity for SARS-CoV-2 diagnosis testing will be
enhanced with the availability and widespread promotion of self-sampling and eventually
SARS-CoV-2 self-testing (SARS-CoV-2ST) (17–19). The benefits of self-sampling and
self-testing include their abilities to help decentralize care, promote social distancing,
conserve PPEs, address transportation and privacy barriers for individuals who do
not want to test at a clinic or a drive-through setting, and reach more individuals
who are not reached with current testing modalities (12, 17, 20). Unlike self-sampling,
SARS-CoV-2ST will allow individuals to receive their results at home without the need
to ship their specimens to a laboratory for testing (21, 22). To our knowledge, there
is only one FDA-approved SARS-CoV-2ST diagnostic kit for individuals to use and receive
their results at home as of November, 17, 2020 (23). However, a number of other different
at-home SARS-CoV-2ST kits are being developed and evaluated to either detect antibodies
or active viral infections (24). Antibody SARS-CoV-2ST kits reveal markers of immune
response that show up in blood more than a week after a person has been infected whereas
active infections will be detected with nucleic acid SARS-CoV-2ST kits through the
virus' genetic materials (24, 25).
As researchers, federal health agencies, and public health practitioners prepare to
implement SARS-CoV-2ST, lessons learned from the global implementation and scaling
up efforts for HIV self-testing (HIVST) can prove useful. We describe research related
to questions that emerged regarding HIVST and how they are similar or different to
the questions that will need to be addressed for SARS-CoV-2ST before this crucial
strategy can be implemented and scaled up successfully. We also discuss the findings
of the first antibody SARS-CoV-2ST acceptability and usability study (22) and the
public health implications of and recommendations people who obtain a positive SARS-CoV-2ST
result for antibodies or active viral infections. Lastly, we identify key structural
inequities in communities that are most affected by COVID-19 that need to be addressed
during future SARS-CoV-2ST implementation efforts.
In-Home HIV Self-Testing History
In 2012, the US FDA approved the first over-the-counter rapid HIVST kit, the OraQuick
In-Home HIV Test which allows users to test for antibodies using saliva sample, similar
to the new saliva-based SARS-CoV-2ST kit (26), and receive a preliminary result at
home in 20 min (27). The benefits of HIVST include privacy, an increase of access
to HIV testing, earlier diagnosis of HIV, confidentiality of results, and reducing
queues for facility-based HIV testing (28). HIVST can also help bypass social barriers
such as stigma and discrimination that deter people from accessing facility-based
HIV testing (28). Since the approval of HIVST, several questions emerged about its
accuracy, acceptability, feasibility, the lack of pre-and-post-test counseling, whether
users would seek a confirmatory test, and link to care (29). There is now overwhelming
evidence that HIVST is accurate, acceptable, feasible, and effective with minimal
social harms (29). As a result from these studies, the World Health Organization (WHO)
now recommends HIVST as one of the testing strategies for HIV prevention efforts (30).
These studies, including our own (31–39), have provided evidence on different distribution
strategies from online platforms, peers to sexual partners, community health workers
(40–42). Similarly, these studies have assessed different approaches to verify HIVST
results either through direct supervision by health provider, requesting participants
to return used HIVST kits, electronic transmission of photographs, or using Bluetooth
sensors (43).
Antibody SARS-CoV-2 Self-Testing Acceptability and Usability
In the first published SARS-CoV-2ST study, researchers in England examined the acceptability
and feasibility of two types (i.e., Guangzhou Wondfo Biotech Co Ltd and Fortress Orient
Gene Biotech Co Ltd) of SARS-CoV-2ST lateral flow immunoassays (LFIAs) or rapid point-of-care
tests that use a blood sample from a finger-prick and produce a self-read result after
10 or 15 min for detection of SARS-CoV-2 antibodies (Immunoglobin M and Immunoglobin
G) (22). Participants received LFIAs by mail and recorded their interpretation of
their results in an online survey with the option to upload a photograph of the results
(22). To assess participants' ability to correctly interpret the test results, a clinician
reviewed all the samples of the uploaded photographs that were reported as positive
and unable to read as well as a random sample of 200 participant-reported negative
or invalid results. Acceptability in the national study was high with 99.3% (8,693/8,754)
and 98.4% (2,911/2,957) of participants reporting that they attempted to use the two
LFIA types (22). Feasibility was also high in the pilot and national studies with
86.5% (225/260) of pilot participants and 97.5 and 97.8% of participants in the national
study reporting they completed all the steps for the tests successfully, respectively
(22). The majority of participants 85.8% (7,272/8,475) and 84.8% (2,416/2,848) uploaded
the photographs of their results with substantial agreement between participant and
clinician interpreted results for both test types (22). However, there were differences
between some of the self-reported results and those reported by the clinician and
some participants reported some difficulties with using the lancet and pipette of
the test kits (22).
Discussion
The scientific and clinical fields involved in HIV prevention have provided extensive
experience, amassed over decades, regarding the value of testing and the added benefits
of in-home self-testing (30). This experience can be brought to bear for SARS-CoV-2ST,
including strategies that can help avoid repeating the pitfalls encountered during
the path toward implementing and scaling up HIVST. For example, limited evidence on
the public health impact and cost-effectiveness of HIVST, uncertain levels of consumer
demand and concerns about potential social harms amongst others delayed the roll out
of HIVST (44). Global efforts and collaborations between WHO, researchers, local health
agencies, donors, and policy makers have addressed some of these limitations. Initiatives
such as but not limited to the Self-Testing AfRica (STAR), the largest HIVST implementation
science project to date (44), 4 Youth by Youth crowdsourced HIVST interventions (45,
46), and Self-Testing Education and Promotion (STEP) project (28, 33), have created
a market for HIVST in sub-Saharan Africa. These initiatives combined with other studies
around the globe have accelerated access to HIVST by gathering the necessary acceptability,
feasibility, and fidelity data, creating an enabling environment with regards to HIVST
policies, generating diverse demand through multiple distribution channels, and creating
advocacy for additional financing, as well as accelerate market entry for suppliers
at affordable and sustainable prices (44, 45, 47–49). Similar initiatives are needed
swiftly to gather additional accuracy, acceptability, feasibility, and programmatic
data to encourage policy makers, donors, and local health agencies to support for
SARS-CoV-2ST implementation and scale up.
While the findings from the first antibody SARS-CoV-2ST acceptability and usability
study in England were promising, some participants reported difficulties using the
pipette and applying the blood drop to the cassette (22). Thus, more studies are needed
to assess ease of use of SARS-CoV-2ST and how to provide the support that potential
users may need. One potential strategy to support SARS-Co-V-2ST users is online real-time
instructions, which has been evaluated with HIVST and found to be acceptable and successful
in increasing HIV testing (50). A recent SARS-CoV-2SS study has shown that participants
are willing to self-collect specimens [saliva, oropharyngeal swab (OPS), and dried
blood spot (DBS) card] at home while being observed by a clinician through a telehealth
session (51). A total of 159 participants were mailed kits and 153 scheduled a video
appointment with the majority of the (n = 143) completing all three self-collected
samples (52). A similar approach can be assessed for SARS-CoV-2ST to move beyond simply
observing potential users to providing additional instructions and post-test supports
in the self-testers receive a positive result.
The public health implications of potential positive antibody SARS-CoV-2ST results
extend beyond treatment since individuals with antibodies for SARS-CoV-2 are considered
to have recovered from COVID-19 and should less symptomatic. However, a positive antibody
SARS-CoV-2ST result will allow individuals, including skeptics, to learn indeed whether
they had a COVID-19 infection—increasing their perception of risk and potentially
positively influencing future behaviors to prevent COVID-19 re-infection. Alternatively,
a positive antibody SARS-CoV-2ST result has the potential to help individuals make
informed decisions about their risk levels as they consider returning to work or interact
with infected individuals (19). In addition, antibody SARS-CoV-2ST results can help
identify qualified individuals who may be interested in donating blood for convalescent
plasmaexternal icon as a treatment for COVID-19. The Centers for Disease Control and
Prevention (CDC) describe general recommendations for positive antibody test results
that people who receive a positive antibody SARS-CoV-2ST result can follow such as
continuing with normal activities, washing hands often, avoiding close contact, wearing
a mask when around others, and continued use of PPE if the person is a health care
worker or first responder (53, 54). On the other hand, a nucleic acid SARS-Co-V2ST
kit will provide individuals with active infections an instant preliminary positive
result that can allow them to follow recommendations for people who are sick such
as self-isolate in order to prevent potential transmission and seek confirmatory diagnostic
testing and early treatment (19).
We must also be mindful that the SARS-CoV-2 transmission profile is not the same as
HIV and it presents immense new challenges that will require us to envision and test
new ways for its easy and reliable detection and its equitable access among marginalized
racial groups, sexual minority ages, incomes and the multitude of intersections between
them. As is the case with HIV, Black communities are disproportionately affected by
COVID-19 (55). This population has experienced extensive barriers to facility-based
HIV testing and HIVST (35) and the pattern seems to be repeating for COVID-19. We
need novel ways to ensure the most vulnerable populations, who are also the most likely
to be infected with and die from COVID-19, have access to affordable SARS-CoV-2ST.
It is important for investigators who are validating SARS-CoV-2ST kits in community
settings to design the studies in a way that ensures adequate representation from
the populations most vulnerable to COVID-19 infection and mortality. To promote adequate
representation of special populations (elderly aged 65 years and older, youth aged
17 years and younger, Black, Latinx, Tribal communities indigenous to North America,
and Spanish-speaking and francophone populations) in SARS-CoV-2ST research and programs,
there are several lessons learned from HIV research and HIVST that can be applied
to COVID-19.
Author Contributions
DFC conceived the idea for the manuscript and drafted it before all authors reviewed
and edited the manuscript into this final form. All authors contributed to the article
and approved the submitted version.
Conflict of Interest
The authors declare that the research was conducted in the absence of any commercial
or financial relationships that could be construed as a potential conflict of interest.