About this data
FasterCures, a center of the Milken Institute, is currently tracking the development of treatments and vaccines for COVID-19 (coronavirus). This tracker contains an aggregation of publicly-available information from validated sources.
Vaccine Product Categories
Live Attenuated Virus
Vaccines work by introducing a foreign protein (an “antigen”) into vaccinated people to trigger an immune response to that antigen. This immune response remembers the foreign protein, and when it sees it again (when a person comes into contact with the virus), it will protect the vaccinated person from developing the disease by recognizing the virus and targeting it for destruction. One way to do this is to simply infect people with a live but weakened (“attenuated”) virus that can still reproduce (make copies of itself) and activate a strong immune response but should not make people sick.
This type of vaccine consists of the disease-causing virus that has been killed (with heat or chemicals), so it won’t make you sick, and can be used in people that may not be able to use a live attenuated virus vaccine (e.g., those who are immunocompromised). In general, inactivated virus vaccines do not provide as strong of an immune response as live attenuated virus vaccines, so additional doses of the vaccine may be needed to get a strong enough immune response. Still, they may be safer for some people.
Subunit vaccines use fragments of the virus, rather than the whole virus, to trigger an immune response in the body. Subunit vaccines typically include an additional substance (called an adjuvant) or require multiple doses to provide an extra boost of protection for long-lasting immunity.
Protein subunit vaccines are similar to inactivated virus vaccines in that they do not contain live viruses. Instead, protein fragments of a killed virus are introduced into the vaccinated person to trigger an immune response that will recognize the protein fragments and therefore recognize the virus.
Another type of vaccine that uses only parts of the virus, virus-like particle (VLP) vaccines also do not contain live viruses (they lack the viral genetic material required to replicate) but resemble the virus closely enough (i.e., they mimic the outer shell of the virus) to trigger an immune response without causing disease.
Nucleic-Acid Vaccines or gene-based vaccines, reflect a “state-of-the-art” approach to vaccination compared to more traditional methods, such as inactivated virus and protein subunit vaccines. Compared to vaccines that contain the whole virus, or parts of the virus, this new approach uses genetic engineering to deliver nucleic acids (DNA or RNA) that carry the instructions for making viral protein(s) (rather than delivering the proteins themselves) into the vaccinated person’s cells. Once in, those cells build the viral proteins that will trigger the immune response. Because these vaccines consist only of nucleic acids (DNA or RNA) and no other viral parts, they are easier and quicker to make and may turn out to be safer than other types of vaccines.
DNA-based vaccines work by inserting a genetically engineered blueprint of viral gene(s) into small DNA molecules (called plasmids) for injection into vaccinated people. Cells take in the DNA plasmids and follow their instructions to build viral proteins, which the immune system recognizes as foreign, triggering the immune response that protects against the disease.
RNA-based vaccines work similarly to DNA-based vaccines, but instead of using DNA, they use a related nucleic acid called RNA, and instead of using plasmids to get into cells, they use fatty molecules (called lipids). Once RNA vaccines are injected into vaccinated people, cells take in the RNAs and follow their instructions to build viral proteins to trigger an immune response.
Viral Vector Vaccines
Viral Vector Vaccines are similar to nucleic-acid vaccines in that they deliver the instructions for making viral protein(s). But, instead of using plasmids or lipids to get them into the cells of a vaccinated person, these vaccines use weakened viruses (called vectors) other than the virus you are vaccinating against to transport the blueprint of viral genes.
Replicating Viral Vector
Replicating viral vector vaccines use a live but weakened viral vector to carry the viral genetic blueprint into cells. Since the viral vector can replicate within cells, the production of viral proteins will be robust, in general producing a stronger immune response against the virus than with a non-replicating viral vector.
Non-Replicating Viral Vector
Non-replicating viral vector vaccines use a killed viral vector to deliver the viral genetic blueprint into cells. Since the vector cannot replicate, in general this type of vaccine does not provide as long-lasting immunity as replicating viral vector vaccines. Therefore, booster shots may be needed to provide ongoing protection against the virus.
This “other” vaccine category is a catchall for anything that doesn’t fit neatly into the other product categories, including those for which details about the vaccine are not yet publicly available.
Treatment Product Categories
Antibodies are one of your body’s natural defense systems against foreign attackers. When your body detects foreign intruders (like bacteria or viruses), your immune system makes antibodies that recognizes them. These specific antibodies attach to the foreign intruders and target them for destruction. To treat or prevent disease, scientists can either use antibodies from the blood of people who have recovered from the infection (i.e., “convalescent plasma”) or use antibodies made in a lab that will attach to and stop (“neutralize”) the foreign intruders. Antibodies created to attach to different molecules in the body (i.e., not foreign intruders) can also be used to treat disease, for example, by turning down your immune response to stop it from overreacting and causing damage to the body (a phenomenon known as “cytokine storm”).
Viruses travel light—they usually only carry a few things they need, including the code to make more of themselves (the “nucleic acid,” either DNA or RNA) and a protective shell around them. They can’t make more of themselves (“replicate”) on their own. They need to get into animal cells, where they hijack the replication system that those cells use. Antiviral treatments stop viruses from making more of themselves by blocking one or more steps in the process.
Cell-based therapies work by transferring into patients live cells to treat a specific disease. To make cell-based therapies, researchers take cells either from the patient (called “autologous” therapies) or from a donor (called “allogeneic” therapies) and either transfer the cells unchanged or change the cells in specific ways to treat a specific disease (e.g., CAR-T therapies). Different cell types from different sources can be used (e.g., stem cells from fat tissue or bone marrow, cells from placenta, T-cells, natural killer [NK] cells). To treat COVID-19 disease, potential cell-based therapies work, in general, by helping the patient’s immune system work better (and not overreact) by releasing signals to other cells in the body to coordinate a proper reaction to the infection and help healing.
Not all potential therapies to treat COVID-19 are drugs. Some are devices or machines that in some way treat a disease. These potential treatments include blood purification devices that filter patients’ blood to remove excess proteins (e.g., cytokines causing the “cytokine storm”) or toxins that are causing problems that can lead to respiratory or organ failure in patients.
RNA molecules carry instructions that tell our cells how to build the proteins they need. As disease treatments, modified (genetically altered) RNA molecules are given to patients that can block the making of specific harmful proteins (e.g., antisense therapy) or make particular helpful proteins (e.g., mRNA therapy). To treat COVID-19, RNA-based therapies can, for example, interfere with the virus hijacking our cells to make more copies of itself by blocking the construction of viral proteins.
Scanning Compounds to Repurpose
Research institutions and pharmaceutical companies have “libraries” of drug compounds discovered or made while exploring their potential to treat various diseases, some of which may have gone on to get FDA approval (and are used today to treat patients) and some of which stayed on laboratory shelves. When COVID-19 hit, many of these organizations started looking back at the drugs in these collections to see if they held something that might help. In addition, some researchers are using new technologies like artificial intelligence to try to use characteristics of the virus to find or design drugs that might successfully treat COVID-19.
This “other” drug category is a catchall for anything that doesn’t fit neatly into the other product categories. These potential treatments vary widely in the ways they work, the diseases they treat (for those approved by the Food and Drug Administration) or are in development to treat, and how they are given to patients. These drugs include things like steroids, malarial drugs, drugs that treat high blood pressure, cancer drugs, drugs that treat the over-reaction of the immune system seen in some COVID-19 patients (i.e., the “cytokine storm”), drugs that treat autoimmune diseases, and drugs that prevent blood clots.
Stages of Development
Initial tests of a potential treatment or vaccine are called “pre-clinical” (i.e., non-human testing). These generally include various tests done in the laboratory (in vitro tests) and studies conducted in animals (in vivo tests) to evaluate its potential to treat the disease.
Potential treatments and vaccines must be tested in people to find out if they are safe and if they work to treat or prevent the disease. In the tracker, vaccines and treatments move up clinical phases when it is publicly reported that the product has been dosed in a trial. Traditionally, testing in humans follows a phased path:
Clinical trials look at the safety of a potential treatment or vaccine in a small group (usually less than 100) of healthy volunteers.
Clinical trials test a potential treatment or vaccine on a large (often up to several hundred) group of people who will use the drug (patients) or get vaccinated (healthy volunteers), looking at whether the treatment or vaccine is safe and whether it works effectively.
Clinical trials continue to test the safety and effectiveness of a treatment or vaccine but on a much larger scale, involving up to several thousand people.
Individual Patient Expanded Access
Individual patient expanded access (or sometimes called compassionate use) is the use of unapproved drugs (i.e., “investigational products,” those that are not approved in the US for any use) to treat individual patients. The FDA has a process set up to allow this use on a person-by-person basis.
Expanded Access Protocols
Expanded access protocols means that an FDA-approved trial has been set up that allows the use of unapproved drugs to treat larger numbers of patients as a group. Once set up, FDA does not have to approve each patient’s use of the drug, and the doctors that run the trial must report certain information to FDA.
Emergency Use Authorization
Emergency Use Authorization is a way for patients to get unapproved drugs or devices to diagnose, treat, or prevent a life-threatening disease during a public health emergency when there are no alternative treatment options. The FDA issues these authorizations.
Published Results and Pre-Prints
For purposes of the tracker, the results column includes published results of research into potential treatments and vaccines in humans, including through clinical trials, observational trials, compassionate or expanded use, and other analyses. Listed results may come from peer-reviewed articles, organization press releases, or pre-print servers (e.g., medRvix or bioRvix). According to medRvix, “Preprints are preliminary reports of work that have not been certified by peer review. They should not be relied on to guide clinical practice or health-related behavior and should not be reported in news media as established information.” In other words, pre-prints are drafts of reports that have not yet been reviewed by other scientists and finalized, so they may turn out to be flawed in some way.