Tracking the
vaccine race
A look at the vaccines in development to fight COVID-19.
The race to create vaccines against the novel coronavirus is entering a critical stretch, with several candidates that were first out of the gate beginning to release late-stage trial data and possibly seeking early regulatory approval. Multiple “winners” are likely to make it to market, and success will depend on a number of factors reflected in this tracker.
A sampling of the leading vaccine candidates and some new technologies to watch, listed in alphabetical order by company or group, and by current development phase.
Vaccines that don’t demonstrate overall safety in small phase 1 and 2 trials will not go any further. Some of the leading coronavirus candidates have the advantage of being based on familiar, time-tested formulas, including candidates containing a viral protein or inactivated whole virus, with or without an immune-boosting adjuvant. Other contenders represent newer technologies, including those based on RNA, DNA or virus-like particles, but even some of these approaches have already led to licensed vaccines against other diseases or at least gone through prior human trials. And they have a few advantages of their own, such as fast manufacture or smaller dose requirements.
Viral vectors are both old and new, having been long in development for other applications and already used in some licensed vaccines. This design reliably provokes an immune response, but the vaccines may also share a potential problem: the harmless viruses that serve as a “vector” to ferry genetic instructions into cells may already be recognized by the human immune system, which can reduce vaccine effectiveness and require higher dosages. Another worry is that a first vaccine shot could create immunity to the vector that weakens the effect of a second shot. For vaccine designers, “it is a risk to be mitigated,” Nathalie Garçon, CEO and CSO of BIOASTER and former chief of GSK Biologicals’ Global Adjuvant Center for Vaccines told Reuters. Large-scale trials will reveal if the risk is serious and if vaccine designers can find a way around it.
Vaccine development normally takes years, starting with preclinical laboratory work. But most pandemic vaccines are being tested in overlapping trial phases to compress the timeline. In Phases 1 and 2, safety and early immune responses are assessed. In Phase 3, researchers will also look at vaccine efficacy: does it protect, who does it protect, and how well? Regulators will use that data in approval decisions. A handful of vaccines are in production already, so as to be ready for rapid distribution when approved.
Clinical trials
pre-clinical
Phase 1
Phase 2
Phase 3
approval
production
Clinical trials
pre-clinical
Phase 1
Phase 2
Phase 3
approval
production
Clinical trials
approval
production
Phase 1
pre-clinical
Phase 2
Phase 3
Regulators aprove
Animal trial
Safety trial
Large group trial
Efficacy trial
Clinical trials
pre-clinical
Phase 1
Phase 2
Phase 3
approval
production
Safety trial
Large group trial
Efficacy trial
Regulators aprove
Animal trial
Whether a pandemic vaccine requires one dose or two, and how far apart shots must be given, can impact how practical it will be to distribute and how much it costs. Phase 3 trials–which typically include tens of thousands of volunteers with a greater diversity of backgrounds and a wider age range than early safety trials–will also reveal a vaccine’s efficacy: how much of the population it is likely to protect, and to what degree.
The race for a vaccine against SARS-CoV-2 is challenging the vaccine industry at every level, Garçon said. Vaccine designers are not only trying to make a single vaccine meant to protect 2 billion people or more, they’ve been doing it without knowing what immune responses equate with protection against this new virus. As a proxy, many compared responses in early trial volunteers to those seen in recovered COVID-19 patients. In phase 3, researchers can begin to see who resists infection in the real world. Experts project the leading candidates might protect roughly 70% of vaccinated people against infection or against severe COVID-19 if they are infected. The U.S. FDA has set a minimum threshold of 50% efficacy to even consider a vaccine for approval. Still not clear is how long that protection will last, but it could be as little as a year, AstraZeneca CEO Pascal Soriot said last June and BioNTech chief executive Ugur Sahin echoed in November.
All the unknowns have not stopped governments and international organizations, including the WHO through its COVAX initiative, from pouring funding into a handful of candidates to speed their development and regulatory review. A fierce international competition to lock in billions of dollars’ worth of purchase commitments has also been underway for months, and some companies will soon start delivering millions of doses.
Initial doses ordered by country
Now, the vaccine candidates must prove themselves. We’re tracking the candidates closest to producing results and a few that represent promising new technologies to watch.
Information about individual vaccine candidates' technology and latest reported results.
Phase 1/2
ARCT-021
Arcturus Therapeutics-Duke NUS
United States
RNA
LATEST RESULTS
Not yet reported
Age range:
21-55, 56-80
Doses trialed:
1
Immune response:
Not yet reported
Side effects:
Not yet reported
OTHER DETAILS
Prior licensed vaccines:
No
Prior trials:
No
Technology:
Self-replicating RNA + LNPs
Advance orders: Israel, Philippines, Singapore
RNA and DNA vaccines are fairly new technology with no previous vaccines of this kind approved for public use. Messenger RNA (mRNA) carrying genetic instructions for making a version of the viral protein "antigen" that the immune system will learn to recognize is often encased in a lipid nanoparticle (LNP), which protects and delivers the fragile molecule into cells.
Messenger RNA that also encodes instructions for making copies of itself, meaning that far smaller amounts of RNA are required per vaccine dose. Encased in lipid nanoparticles (LNP).
In phase 1 and 2 trials, the focus is on side effects of the vaccine itself, such as headache or pain at the injection site, and any serious adverse effects like fever, but also on measuring early immune responses. Many groups compare the antibody levels generated in trial volunteers to those seen in recovered COVID-19 patients to see if the vaccine provokes responses that are high, low or about equal (moderate) to a natural infection.
In phase 1 and 2 trials, researchers often test the effect of one or two doses of a vaccine spaced days or weeks apart, and of multiple dosages to measure both side effects and immune responses. These tests help in choosing just one or two protocols with the best combination of safety and immune responses to be tested in the phase 3 trial.
Vaccine designs based on time-tested formulas, including those containing a viral protein or inactivated whole virus, with or without immune-boosting adjuvant, have the advantage of a long safety and performance record in previous licensed vaccines. Newer technologies have less of a track record, but many of the current contenders are based on a specific design, vector or formulation that has been through human trials in vaccines against other diseases. For technologies never tested in people, the current race will be a critical first demonstration of their potential.
Concurrent phase 1/2; 2/3
AZD1222
AstraZeneca-Oxford
United Kingdom
Viral vector
LATEST RESULTS
Dec. 8; Phase 3
Age range:
18-55; 56+
Doses trialed:
2 (0 and 28 days)
Immune response:
70.4% efficacy
Side effects:
Mild
OTHER DETAILS
Prior licensed vaccines:
No
Prior trials:
MERS, Chikungunya, Flu, Hep B, Malaria, RSV, TB, Zika, Prostate cancer
Technology:
Nonreplicating chimpanzee adenovirus vector
Advance orders: Australia, Brazil, Canada, Chile, COVAX, Ecuador, EU, France, Germany, India, Israel, Italy, Japan, Malaysia, Morocco, Netherlands, Panama, Philippines, S. Korea, Spain, Switzerland, UK, U.S., Vietnam
The viral vector vaccine uses harmless viruses, like adenoviruses, which cause the common cold, as vehicles to ferry genetic instructions similar to those in RNA vaccines into human cells. To make viral vector vaccines, part of the genome of the harmless virus is replaced with genetic instructions for making a coronavirus protein. The viral vector can replicate or not replicate inside human cells, depending on the vaccine type. Replicating vectors remain active longer, and tend to provoke a strong immune response.
A modified version of an adenovirus that usually infects chimpanzees, this vector was originally developed to avoid the possibility that pre-existing immunity to human "common cold" adenoviruses could weaken a vaccine's effect
In phase 3 trials, the focus shifts to analyzing immune responses to the vaccine in greater detail and in a larger and more diverse group of people. Vaccine "efficacy" is described as the percentage of vaccinated people who are protected from infection by the virus or from developing severe illness if they are infected.
In phase 1 and 2 trials, researchers often test the effect of one or two doses of a vaccine spaced days or weeks apart, and of multiple dosages to measure both side effects and immune responses. These tests help in choosing just one or two protocols with the best combination of safety and immune responses to be tested in the phase 3 trial.
Vaccine designs based on time-tested formulas, including those containing a viral protein or inactivated whole virus, with or without immune-boosting adjuvant, have the advantage of a long safety and performance record in previous licensed vaccines. Newer technologies have less of a track record, but many of the current contenders are based on a specific design, vector or formulation that has been through human trials in vaccines against other diseases. For technologies never tested in people, the current race will be a critical first demonstration of their potential.
Concurrent phase 1; 2; 3
Ad5-nCov
CanSino Biologics
China
Viral vector
LATEST RESULTS
July 20; Phase 2
Age range:
18+
Doses trialed:
1
Immune response:
High
Side effects:
9% severe
OTHER DETAILS
Prior licensed vaccines:
Ebola
Prior trials:
Technology:
Nonreplicating adenovirus vector
Advance orders: Mexico
The viral vector vaccine uses harmless viruses like adenoviruses, which cause the common cold, as vehicles to ferry genetic instructions into human cells. To make viral vector vaccines, part of the genome of the harmless virus is replaced with instructions for making a coronavirus protein. The viral vector can replicate or not replicate inside human cells, depending on the vaccine type. Replicating vectors remain active longer, and tend to provoke a strong immune response.
The nonreplicating adenovirus vector vaccine uses harmless adenoviruses, which cause the common cold, to ferry genetic instructions for making a coronavirus protein "antigen" into human cells.
In phase 1 and 2 trials, the focus is on side effects of the vaccine itself, such as headache or pain at the injection site, and any serious adverse effects like fever, but also on measuring early immune responses. Many groups compare the antibody levels generated in trial volunteers to those seen in recovered COVID-19 patients to see if the vaccine provokes responses that are high, low or about equal (moderate) to a natural infection.
In phase 1 and 2 trials, researchers often test the effect of one or two doses of a vaccine spaced days or weeks apart, and of multiple dosages to measure both side effects and immune responses. These tests help in choosing just one or two protocols with the best combination of safety and immune responses to be tested in the phase 3 trial.
Vaccine designs based on time-tested formulas, including those containing a viral protein or inactivated whole virus, with or without immune-boosting adjuvant, have the advantage of a long safety and performance record in previous licensed vaccines. Newer technologies have less of a track record, but many of the current contenders are based on a specific design, vector or formulation that has been through human trials in vaccines against other diseases. For technologies never tested in people, the current race will be a critical first demonstration of their potential.
Concurrent phase 1; 2; 2/3
CVnCoV
CureVac AG-Bayer
Germany
RNA
LATEST RESULTS
Nov. 2; Phase 1
Age range:
18-60
Doses trialed:
1 or 2 (0 and 29 days)
Immune response:
Moderate
Side effects:
Mild to moderate
OTHER DETAILS
Prior licensed vaccines:
No
Prior trials:
Rabies
Technology:
mRNA + LNPs
Advance orders: COVAX, EU, Germany
RNA and DNA vaccines are fairly new technology with no previous vaccines of this kind approved for public use. Messenger RNA (mRNA) carrying genetic instructions for making a version of the viral protein "antigen" that the immune system will learn to recognize is often encased in a lipid nanoparticle (LNP), which protects and delivers the fragile molecule into cells.
Messenger RNA (mRNA) carrying genetic instructions for making a version of the viral protein "antigen" that the immune system will learn to recognize is often encased in a lipid nanoparticle (LNP), which protects and delivers the fragile molecule into cells.
In phase 1 and 2 trials, the focus is on side effects of the vaccine itself, such as headache or pain at the injection site, and any serious adverse effects like fever, but also on measuring early immune responses. Many groups compare the antibody levels generated in trial volunteers to those seen in recovered COVID-19 patients to see if the vaccine provokes responses that are high, low or about equal (moderate) to a natural infection.
In phase 1 and 2 trials, researchers often test the effect of one or two doses of a vaccine spaced days or weeks apart, and of multiple dosages to measure both side effects and immune responses. These tests help in choosing just one or two protocols with the best combination of safety and immune responses to be tested in the phase 3 trial.
Vaccine designs based on time-tested formulas, including those containing a viral protein or inactivated whole virus, with or without immune-boosting adjuvant, have the advantage of a long safety and performance record in previous licensed vaccines. Newer technologies have less of a track record, but many of the current contenders are based on a specific design, vector or formulation that has been through human trials in vaccines against other diseases. For technologies never tested in people, the current race will be a critical first demonstration of their potential.
Concurrent phase 2; 3
Sputnik V
Gamaleya Research Institute
Russian Federation
Viral vector
LATEST RESULTS
Sep 4; Phase 2
Age range:
18-60
Doses trialed:
2 (0 and 21 days)
Immune response:
Moderate
Side effects:
Mild
OTHER DETAILS
Prior licensed vaccines:
Ebola
Prior trials:
MERS, Flu
Technology:
Nonreplicating adenovirus vectors
Advance orders: Argentina, Brazil, Egypt, Hungary, India, Malaysia,Mexico, Nepal, Paraguay, Uzbekistan, Vietnam
The viral vector vaccine uses harmless viruses like adenoviruses, which cause the common cold, as vehicles to ferry genetic instructions into human cells. To make viral vector vaccines, part of the genome of the harmless virus is replaced with instructions for making a coronavirus protein. The viral vector can replicate or not replicate inside human cells, depending on the vaccine type. Replicating vectors remain active longer, and tend to provoke a strong immune response.
Two different adenovirus vectors, AD26 and AD5, are used in the first and second shots of this vaccine, to avoid vector immunity generated by the first shot weakening the effect of the booster shot.
In phase 1 and 2 trials, the focus is on side effects of the vaccine itself, such as headache or pain at the injection site, and any serious adverse effects like fever, but also on measuring early immune responses. Many groups compare the antibody levels generated in trial volunteers to those seen in recovered COVID-19 patients to see if the vaccine provokes responses that are high, low or about equal (moderate) to a natural infection.
In phase 1 and 2 trials, researchers often test the effect of one or two doses of a vaccine spaced days or weeks apart, and of multiple dosages to measure both side effects and immune responses. These tests help in choosing just one or two protocols with the best combination of safety and immune responses to be tested in the phase 3 trial.
Vaccine designs based on time-tested formulas, including those containing a viral protein or inactivated whole virus, with or without immune-boosting adjuvant, have the advantage of a long safety and performance record in previous licensed vaccines. Newer technologies have less of a track record, but many of the current contenders are based on a specific design, vector or formulation that has been through human trials in vaccines against other diseases. For technologies never tested in people, the current race will be a critical first demonstration of their potential.
Concurrent phase 1/2; 2/3
INO-4800
Inovio-CEPI
United States
DNA
LATEST RESULTS
Dec. 23; Phase 1
Age range:
18-50
Doses trialed:
2(0 and 28 days)
Immune response:
Moderate
Side effects:
Mild
OTHER DETAILS
Prior licensed vaccines:
No
Prior trials:
Ebola, Flu, Lassa, MERS
Technology:
DNA plasmid
Advance orders: COVAX
RNA and DNA vaccines are fairly new technology with no previous vaccines of this kind approved for public use. DNA carrying genetic instructions for making a version of the viral protein "antigen" that the immune system will learn to recognize is often incorporated into a harmless ring known as a plasmid, which ferries the molecule into cells.
A ring of DNA genetically engineered to incorporate instructions for human cells to make a version of a virus protein that the immune system will learn to recognize. Inovio uses its Cellectra device to deliver the vaccine into the skin with "electroporation," a tiny electric charge that helps cells to take in the DNA.
In phase 1 and 2 trials, the focus is on side effects of the vaccine itself, such as headache or pain at the injection site, and any serious adverse effects like fever, but also on measuring early immune responses. Many groups compare the antibody levels generated in trial volunteers to those seen in recovered COVID-19 patients to see if the vaccine provokes responses that are high, low or about equal (moderate) to a natural infection.
In phase 1 and 2 trials, researchers often test the effect of one or two doses of a vaccine spaced days or weeks apart, and of multiple dosages to measure both side effects and immune responses. These tests help in choosing just one or two protocols with the best combination of safety and immune responses to be tested in the phase 3 trial.
Vaccine designs based on time-tested formulas, including those containing a viral protein or inactivated whole virus, with or without immune-boosting adjuvant, have the advantage of a long safety and performance record in previous licensed vaccines. Newer technologies have less of a track record, but many of the current contenders are based on a specific design, vector or formulation that has been through human trials in vaccines against other diseases. For technologies never tested in people, the current race will be a critical first demonstration of their potential.
Concurrent phase 1/2; 3
Ad26 SARS-CoV-2
Johnson & Johnson-BARDA-Janssen
United States
Viral vector
LATEST RESULTS
Jan. 12; Phase 1/2
Age range:
18-55, 65+
Doses trialed:
1 or 2 (0 and 58 days)
Immune response:
Moderate
Side effects:
Mild to moderate
OTHER DETAILS
Prior licensed vaccines:
Ebola
Prior trials:
HIV, RSV, Zika
Technology:
Nonreplicating adenovirus vector
Advance orders: Canada, COVAX, EU, UK, U.S.
The viral vector vaccine uses harmless viruses like adenoviruses, which cause the common cold, as vehicles to ferry genetic instructions into human cells. To make viral vector vaccines, part of the genome of the harmless virus is replaced with instructions for making a coronavirus protein. The viral vector can replicate or not replicate inside human cells, depending on the vaccine type. Replicating vectors remain active longer, and tend to provoke a strong immune response.
The nonreplicating adenovirus vector vaccine uses harmless adenoviruses, which cause the common cold, to ferry genetic instructions for making a coronavirus protein into human cells.
In phase 1 and 2 trials, the focus is on side effects of the vaccine itself, such as headache or pain at the injection site, and any serious adverse effects like fever, but also on measuring early immune responses. Many groups compare the antibody levels generated in trial volunteers to those seen in recovered COVID-19 patients to see if the vaccine provokes responses that are high, low or about equal (moderate) to a natural infection. J&J results reported on September 25 included only 15 participants over age 65, and their immune responses to the vaccine were less robust than those of younger participants.
In phase 1 and 2 trials, researchers often test the effect of one or two doses of a vaccine spaced days or weeks apart, and of multiple dosages to measure both side effects and immune responses. These tests help in choosing just one or two protocols with the best combination of safety and immune responses to be tested in the phase 3 trial. In results reported September 25, J&J researchers described responses to a single high- or low-dose shot.
Vaccine designs based on time-tested formulas, including those containing a viral protein or inactivated whole virus, with or without immune-boosting adjuvant, have the advantage of a long safety and performance record in previous licensed vaccines. Newer technologies have less of a track record, but many of the current contenders are based on a specific design, vector or formulation that has been through human trials in vaccines against other diseases. For technologies never tested in people, the current race will be a critical first demonstration of their potential.
Phase 2/3
CoVLP
Medicago-GSK-Dynavax
Canada
Virus-like particle
LATEST RESULTS
Nov. 6; Phase 1
Age range:
18-55
Doses trialed:
2 (0 and 21 days)
Immune response:
Moderate-High
Side effects:
Mild to moderate
OTHER DETAILS
Prior licensed vaccines:
No
Prior trials:
Flu
Technology:
VLP + adjuvant
Advance orders: Canada
A vaccine made with virus-like particles introduces tiny assembled structures that closely resemble the coronavirus but contain no viral genetic material. It’s like an empty shell that looks like the SARS-CoV-2 virus. The immune system will learn to recognize the viral proteins but the particle is incapable of generating more copies of itself.
Resembling an empty coronavirus shell, the virus-like particle will teach the immune system to recognize viral proteins with the aid of an immune-boosting adjuvant: Medicago is testing two adjuvant types, one made from a bacterial protein called CpG and the other an oil-based substance called AS03 that has been used in licensed flu vaccines. Late-stage trials will only move forward with the ASO3 adjuvant, the company said in November.
In phase 1 and 2 trials, the focus is on side effects of the vaccine itself, such as headache or pain at the injection site, and any serious adverse effects like fever, but also on measuring early immune responses. Many groups compare the antibody levels generated in trial volunteers to those seen in recovered COVID-19 patients to see if the vaccine provokes responses that are high, low or about equal (moderate) to a natural infection.
In phase 1 and 2 trials, researchers often test the effect of one or two doses of a vaccine spaced days or weeks apart, and of multiple dosages to measure both side effects and immune responses. These tests help in choosing just one or two protocols with the best combination of safety and immune responses to be tested in the phase 3 trial.
Vaccine designs based on time-tested formulas, including those containing a viral protein or inactivated whole virus, with or without immune-boosting adjuvant, have the advantage of a long safety and performance record in previous licensed vaccines. Newer technologies have less of a track record, but many of the current contenders are based on a specific design, vector or formulation that has been through human trials in vaccines against other diseases. For technologies never tested in people, the current race will be a critical first demonstration of their potential.
Phase 1
V591
Merck-IAVI-BARDA
Multinational
Viral vector
LATEST RESULTS
Jan. 25; Discontinuation
Age range:
18-55; 60+
Doses trialed:
2 (0 and 57 days)
Immune response:
Low
Side effects:
Not reported
OTHER DETAILS
Prior licensed vaccines:
Ebola, Marburg, Lassa
Prior trials:
HIV
Technology:
Replicating vesicular stomatitis virus vector
Advance orders:
The viral vector vaccine uses harmless viruses like adenoviruses, which cause the common cold, as vehicles to ferry genetic instructions into human cells. To make viral vector vaccines, part of the genome of the harmless virus is replaced with instructions for making a coronavirus protein. The viral vector can replicate or not replicate inside human cells, depending on the vaccine type. Replicating vectors remain active longer, and tend to provoke a strong immune response.
Recombinant vesicular stomatitis virus (rVSV) vector, an animal virus that was used in Merck’s EU- and U.S.-approved Ebola Zaire virus vaccine, has also been explored in vaccines against HIV and other viruses.
In phase 1 and 2 trials, the focus is on side effects of the vaccine itself, such as headache or pain at the injection site, and any serious adverse effects like fever, but also on measuring early immune responses. Many groups compare the antibody levels generated in trial volunteers to those seen in recovered COVID-19 patients to see if the vaccine provokes responses that are high, low or about equal (moderate) to a natural infection.
In phase 1 and 2 trials, researchers often test the effect of one or two doses of a vaccine spaced days or weeks apart, and of multiple dosages to measure both side effects and immune responses. These tests help in choosing just one or two protocols with the best combination of safety and immune responses to be tested in the phase 3 trial.
Vaccine designs based on time-tested formulas, including those containing a viral protein or inactivated whole virus, with or without immune-boosting adjuvant, have the advantage of a long safety and performance record in previous licensed vaccines. Newer technologies have less of a track record, but many of the current contenders are based on a specific design, vector or formulation that has been through human trials in vaccines against other diseases. For technologies never tested in people, the current race will be a critical first demonstration of their potential.
Phase 1/2
TMV-083
Merck-Themis
Multinational
Viral vector
LATEST RESULTS
Jan. 25; Discontinuation
Age range:
18-55; 60+
Doses trialed:
1 or 2
Immune response:
Low
Side effects:
Not reported
OTHER DETAILS
Prior licensed vaccines:
No
Prior trials:
Chikunguya, Ebola, HIV, Lassa, West Nile, Zika
Technology:
Replicating measles vector
Advance orders: COVAX
The viral vector vaccine uses harmless viruses like adenoviruses, which cause the common cold, as vehicles to ferry genetic instructions into human cells. To make viral vector vaccines, part of the genome of the harmless virus is replaced with instructions for making a coronavirus protein. The viral vector can replicate or not replicate inside human cells, depending on the vaccine type. Replicating vectors remain active longer, and tend to provoke a strong immune response.
Recombinant measles virus vector originally developed by the Institut Pasteur.
In phase 1 and 2 trials, the focus is on side effects of the vaccine itself, such as headache or pain at the injection site, and any serious adverse effects like fever, but also on measuring early immune responses. Many groups compare the antibody levels generated in trial volunteers to those seen in recovered COVID-19 patients to see if the vaccine provokes responses that are high, low or about equal (moderate) to a natural infection.
In phase 1 and 2 trials, researchers often test the effect of one or two doses of a vaccine spaced days or weeks apart, and of multiple dosages to measure both side effects and immune responses. These tests help in choosing just one or two protocols with the best combination of safety and immune responses to be tested in the phase 3 trial.
Vaccine designs based on time-tested formulas, including those containing a viral protein or inactivated whole virus, with or without immune-boosting adjuvant, have the advantage of a long safety and performance record in previous licensed vaccines. Newer technologies have less of a track record, but many of the current contenders are based on a specific design, vector or formulation that has been through human trials in vaccines against other diseases. For technologies never tested in people, the current race will be a critical first demonstration of their potential.
Concurrent phase 1; 2; 3
mRNA-1273
Moderna-NIAID
United States
RNA
LATEST RESULTS
Nov. 16; Phase 3
Age range:
56-70, 70+
Doses trialed:
2 (0 and 28 days)
Immune response:
94.1% efficacy
Side effects:
Mild to moderate
OTHER DETAILS
Prior licensed vaccines:
No
Prior trials:
Cytomegalovirus, Zika
Technology:
mRNA + LNPs
Advance orders: Canada, COVAX, EU, Israel, Japan, Netherlands, Philippines, Qatar, Switzerland, UK, U.S.
RNA and DNA vaccines are fairly new technology with no previous vaccines of this kind approved for public use. Messenger RNA (mRNA) carrying genetic instructions for making a version of the viral protein "antigen" that the immune system will learn to recognize is often encased in a lipid nanoparticle (LNP), which protects and delivers the fragile molecule into cells.
Messenger RNA (mRNA) carrying genetic instructions for making a version of the viral protein "antigen" that the immune system will learn to recognize is often encased in a lipid nanoparticle (LNP), which protects and delivers the fragile molecule into cells.
In phase 3 trials, the focus shifts to analyzing immune responses to the vaccine in greater detail and in a larger and more diverse group of people. Vaccine "efficacy" is described as the percentage of vaccinated people who are protected from infection by the virus or from developing severe illness if they are infected.
In phase 1 and 2 trials, researchers often test the effect of one or two doses of a vaccine spaced days or weeks apart, and of multiple dosages to measure both side effects and immune responses. These tests help in choosing just one or two protocols with the best combination of safety and immune responses to be tested in the phase 3 trial.
Vaccine designs based on time-tested formulas, including those containing a viral protein or inactivated whole virus, with or without immune-boosting adjuvant, have the advantage of a long safety and performance record in previous licensed vaccines. Newer technologies have less of a track record, but many of the current contenders are based on a specific design, vector or formulation that has been through human trials in vaccines against other diseases. For technologies never tested in people, the current race will be a critical first demonstration of their potential.
Concurrent phase 1/2; 2; 3
NVX-CoV2373
Novavax
United States
Protein subunit
LATEST RESULTS
Jan. 28; Phase 3
Age range:
18-84
Doses trialed:
2 (0 and 21 days)
Immune response:
89.3% efficacy; 60% in S. Africa
Side effects:
Mild
OTHER DETAILS
Prior licensed vaccines:
No
Prior trials:
RSV, Flu, Ebola, HPV, VZV
Technology:
Antigen + adjuvant
Advance orders: Australia, Canada, COVAX, Japan, New Zealand, UK, U.S.
The protein subunit vaccine presents the antigen (a specific viral protein) to the body. It contains only the protein subunit, and no other viral particles. Often, an adjuvant is added to this kind of vaccine to boost immune responses to the antigen.
A viral protein "antigen" the immune system will learn to recognize plus an added "adjuvant" that boosts immune responses to the antigen. Adjuvants can be made from a variety of oily substances, alum, synthetic molecules, bacterial proteins, or even specific RNA motifs.
In phase 3 trials, the focus shifts to analyzing immune responses to the vaccine in greater detail and in a larger and more diverse group of people. Vaccine "efficacy" is described as the percentage of vaccinated people who are protected from infection by the virus or from developing severe illness if they are infected.
In phase 1 and 2 trials, researchers often test the effect of one or two doses of a vaccine spaced days or weeks apart, and of multiple dosages to measure both side effects and immune responses. These tests help in choosing just one or two protocols with the best combination of safety and immune responses to be tested in the phase 3 trial.
Vaccine designs based on time-tested formulas, including those containing a viral protein or inactivated whole virus, with or without immune-boosting adjuvant, have the advantage of a long safety and performance record in previous licensed vaccines. Newer technologies have less of a track record, but many of the current contenders are based on a specific design, vector or formulation that has been through human trials in vaccines against other diseases. For technologies never tested in people, the current race will be a critical first demonstration of their potential.
Concurrent phase 1/2; 2/3
COMIRNATY
Pfizer-BioNtech
Multinational
RNA
LATEST RESULTS
Dec. 10; Phase 2/3
Age range:
16+
Doses trialed:
2 (0 and 21 days)
Immune response:
95% efficacy
Side effects:
Mild to moderate
OTHER DETAILS
Prior licensed vaccines:
No
Prior trials:
Flu
Technology:
mRNA + LNPs
Advance orders: Bahrain, Canada, Chile, Dubai, Ecuador, EU, Germany, Israel, Japan, Malaysia, Mexico, Netherlands, Panama, Peru, Spain, Switzerland, UK, U.S.
RNA and DNA vaccines are fairly new technology with no previous vaccines of this kind approved for public use. Messenger RNA (mRNA) carrying genetic instructions for making a version of the viral protein "antigen" that the immune system will learn to recognize is often encased in a lipid nanoparticle (LNP), which protects and delivers the fragile molecule into cells.
Messenger RNA (mRNA) carrying genetic instructions for making a version of the viral protein "antigen" that the immune system will learn to recognize is often encased in a lipid nanoparticle (LNP), which protects and delivers the fragile molecule into cells.
In phase 3 trials, the focus shifts to analyzing immune responses to the vaccine in greater detail and in a larger and more diverse group of people. Vaccine "efficacy" is described as the percentage of vaccinated people who are protected from infection by the virus or from developing severe illness if they are infected.
In phase 1 and 2 trials, researchers often test the effect of one or two doses of a vaccine spaced days or weeks apart, and of multiple dosages to measure both side effects and immune responses. These tests help in choosing just one or two protocols with the best combination of safety and immune responses to be tested in the phase 3 trial.
Vaccine designs based on time-tested formulas, including those containing a viral protein or inactivated whole virus, with or without immune-boosting adjuvant, have the advantage of a long safety and performance record in previous licensed vaccines. Newer technologies have less of a track record, but many of the current contenders are based on a specific design, vector or formulation that has been through human trials in vaccines against other diseases. For technologies never tested in people, the current race will be a critical first demonstration of their potential.
Phase 1/2
S protein (baculovirus production)
Sanofi-GSK
Multinational
Protein subunit
LATEST RESULTS
Dec. 11; Phase 1/2 trial
Age range:
18-49; 50+
Doses trialed:
1 or 2 (0 and 21 days)
Immune response:
Moderate; Low in older adults
Side effects:
Mild to moderate
OTHER DETAILS
Prior licensed vaccines:
Flu
Prior trials:
Multiple
Technology:
Antigen + adjuvant
Advance orders: Canada, EU, UK, U.S.
The protein subunit vaccine presents the antigen (a specific viral protein) to the body. It contains only the protein subunit, and no other viral particles. Often, an adjuvant is added to this kind of vaccine to boost immune responses to the antigen.
A viral protein "antigen" the immune system will learn to recognize, plus an added "adjuvant" that boosts immune responses to the antigen. GSK's AS03 adjuvant has been used in previous licensed flu vaccines.
In phase 1 and 2 trials, the focus is on side effects of the vaccine itself, such as headache or pain at the injection site, and any serious adverse effects like fever, but also on measuring early immune responses. Many groups compare the antibody levels generated in trial volunteers to those seen in recovered COVID-19 patients to see if the vaccine provokes responses that are high, low or about equal (moderate) to a natural infection.
In phase 1 and 2 trials, researchers often test the effect of one or two doses of a vaccine spaced days or weeks apart, and of multiple dosages to measure both side effects and immune responses. These tests help in choosing just one or two protocols with the best combination of safety and immune responses to be tested in the phase 3 trial.
Vaccine designs based on time-tested formulas, including those containing a viral protein or inactivated whole virus, with or without immune-boosting adjuvant, have the advantage of a long safety and performance record in previous licensed vaccines. Newer technologies have less of a track record, but many of the current contenders are based on a specific design, vector or formulation that has been through human trials in vaccines against other diseases. For technologies never tested in people, the current race will be a critical first demonstration of their potential.
Concurrent phase 1/2; 3
BBIBP-CorV
Sinopharm-Beijing Inst.of Biological Products
China
Inactivated virus
LATEST RESULTS
Aug 13; Phase 1/2
Age range:
18-59
Doses trialed:
2 (0 and 14 or 21 days)
Immune response:
Moderate
Side effects:
Mild to moderate
OTHER DETAILS
Prior licensed vaccines:
Multiple
Prior trials:
Multiple
Technology:
Inactivated virus + adjuvant
Advance orders: Dubai, Morocco, Peru
An inactivated vaccine is produced by disabling a virus through heat, chemicals or radiation. The virus cannot cause disease, but the inactivation process can weaken the immune response this type of vaccine evokes, and booster shots are often necessary.
Weakened whole virus plus an added "adjuvant" that boosts immune responses to the antigen. Adjuvants can be made from a variety of oily substances, alum, synthetic molecules, bacterial proteins, or even specific RNA motifs.
In phase 1 and 2 trials, the focus is on side effects of the vaccine itself, such as headache or pain at the injection site, and any serious adverse effects like fever, but also on measuring early immune responses. Many groups compare the antibody levels generated in trial volunteers to those seen in recovered COVID-19 patients to see if the vaccine provokes responses that are high, low or about equal (moderate) to a natural infection.
In phase 1 and 2 trials, researchers often test the effect of one or two doses of a vaccine spaced days or weeks apart, and of multiple dosages to measure both side effects and immune responses. These tests help in choosing just one or two protocols with the best combination of safety and immune responses to be tested in the phase 3 trial.
Vaccine designs based on time-tested formulas, including those containing a viral protein or inactivated whole virus, with or without immune-boosting adjuvant, have the advantage of a long safety and performance record in previous licensed vaccines. Newer technologies have less of a track record, but many of the current contenders are based on a specific design, vector or formulation that has been through human trials in vaccines against other diseases. For technologies never tested in people, the current race will be a critical first demonstration of their potential.
Concurrent phase 1/2; 3
CoronaVac
Sinovac-Instituto Buntantan
China/Brazil
Inactivated virus
LATEST RESULTS
Jan. 12; Phase 3
Age range:
18-59; 60+
Doses trialed:
2 (0 and 14 days)
Immune response:
50.4% efficacy
Side effects:
Not yet reported
OTHER DETAILS
Prior licensed vaccines:
Multiple
Prior trials:
SARS-CoV-1
Technology:
Inactivated virus
Advance orders: Brazil, Chile, Indonesia, Philippines, Singapore, Turkey
An inactivated vaccine is produced by disabling a virus through heat, chemicals or radiation. The virus cannot cause disease, but the inactivation process can weaken the immune response this type of vaccine evokes, and booster shots are often necessary.
An inactivated vaccine is produced by disabling a virus through heat, chemicals or radiation. The virus cannot cause disease, but the inactivation process can weaken the immune response this type of vaccine evokes, and booster shots are often necessary.
In phase 3 trials, the focus shifts to analyzing immune responses to the vaccine in greater detail and in a larger and more diverse group of people. Vaccine "efficacy" is described as the percentage of vaccinated people who are protected from infection by the virus or from developing severe illness if they are infected.
In phase 1 and 2 trials, researchers often test the effect of one or two doses of a vaccine spaced days or weeks apart, and of multiple dosages to measure both side effects and immune responses. These tests help in choosing just one or two protocols with the best combination of safety and immune responses to be tested in the phase 3 trial.
Vaccine designs based on time-tested formulas, including those containing a viral protein or inactivated whole virus, with or without immune-boosting adjuvant, have the advantage of a long safety and performance record in previous licensed vaccines. Newer technologies have less of a track record, but many of the current contenders are based on a specific design, vector or formulation that has been through human trials in vaccines against other diseases. For technologies never tested in people, the current race will be a critical first demonstration of their potential.
Reuters reporting, companies, Vaccine Centre at the London School of Hygiene and Tropical Medicine, WHO, PHARMAnetwork
Reporting and writing by Christine Soares
Graphics, design and development by Travis Hartman
Illustrations by Ally Levine