After the emergency use authorizations (EUA) were given for the Moderna and Pfizer COVID-19 vaccines, what is next in the pipeline? There are three vaccines that could be reviewed by the Vaccines and Related Biological Products Advisory Committee (VRBPAC) during the next few weeks that would provide recommendations to the FDA (and other national drug regulatory bodies) for EUAs.
The three vaccines I’m going to discuss are ones that have a reasonable chance of getting approved for use in the USA or Europe. This excludes COVID-19 vaccines from Russia, China, and other countries that rarely, if ever, get FDA approval for vaccines (see Note 1).
So, let’s take a look at what are probably the next three COVID-19 vaccines in the pipeline.
The COVID-19 vaccines pipeline
There appear to be three COVID-19 vaccines that are very close to submitting documents to VRBPAC, maybe by the end of January 2021. Of course, having more COVID-19 vaccines across the world will help alleviate shortages of vaccines and get more people vaccinated so we might be able to end this coronavirus pandemic.
The following information is listed for each of the three vaccines. :
- Vaccine candidate. Until a vaccine is approved for use, most companies use code names for the vaccine candidate.
- Type of vaccine.
- Status. Ongoing or recruiting (some could be both).
- The number of doses. This is a consideration with respect to distribution and patient compliance.
- Clinical trial identifier. This will give a link to the clinical trials database which tracks all clinical trials around the world for new drugs or vaccines. In general, a clinical trial needs to be listed in this database to be included in any FDA drug applications. You can look up all the details about the clinical trial, like locations and how to volunteer in some cases, by clicking on this link.
Astra-Zeneca
Vaccine candidate name: AZD1222
Type of vaccine: This uses a replication-deficient chimpanzee viral vector based on a weakened version of a common cold virus (adenovirus) that causes infections in chimpanzees and contains the genetic material of the SARS-CoV-2 virus spike protein. After vaccination, the surface spike protein is produced, priming the immune system to attack the SARS-CoV-2 virus if it later infects the body.
To try to put this into as non-technical terms as I can, recombinant vaccines use a small piece of genetic material from the SARS-CoV-2 virus to trigger an immune response. This genetic material does not replicate in the body. The spike protein of the virus can be targeted, and these vaccines are generally safe to use in a large population of people—even those with chronic health problems or who are immunocompromised.
Pneumococcal and meningococcal disease vaccines use this type of technology. It is safe and effective in those cases.
Phase 3 status: Ongoing, with goals to include over 60,000 participants. An interim analysis published in The Lancet stated that over 20,000 participants enrolled across four clinical trials in the UK and Brazil and South Africa.
Number of doses: 2 (same as the Pfizer and Moderna vaccines)
Clinical trial identifier: NCT04516746 NCT04540393
The University of Oxford Jenner Institute developed a vaccine candidate based on a chimp adenovirus vector. AstraZeneca is responsible for the development, manufacturing, and distribution of the vaccine.
The preliminary results from the phase 3 clinical trials showed about a 70% effectiveness of the vaccine, although a different dosage regimen showed much higher effectiveness.
The quality of these clinical trials have been criticized heavily:
The Oxford-AstraZeneca story is very different, though. Presumably, neither of the two trials from which they combined data could have provided a clear answer on the vaccine’s efficacy on its own. To make things worse, Oxford-AstraZeneca reported only the results for certain subgroups of people within each one. (For perspective on this: The two subgroups chosen leave out perhaps half the people in the Brazilian trial.) Meanwhile, one of their key claims is that giving half a dose of the vaccine on the first injection, followed by a standard dose on the second one, led to better outcomes—but neither of these trials had been designed to test this hypothesis. In fact, it’s since emerged that the half-dose/full-dose option started out as a mistake, and one that was only caught when some people in the study didn’t have the usual high rate of adverse effects.
This is not what Pfizer and Moderna have done – they did not make mistakes in their trial protocol nor have they tried to cherry-pick data, something that AstraZeneca has done. It is entirely possible that this vaccine may not get the EUA from the FDA, but the pressure to get more vaccines may be overwhelming, so stay tuned.
However, in December 2020, AstraZeneca announced that they had received a EUA for the vaccine in the UK.
Janssen Vaccines & Prevention (Johnson and Johnson)
Vaccine candidate name: Ad26.COV2.S
Type of vaccine: A recombined adenovirus vector that expresses the S-subunit of the SARS-CoV-2 virus to induce an immune response. This is similar to the AstraZeneca vaccine.
Phase 3 status: Ongoing/recruiting over 90,000 participants into two different trials (that use two different dosing regimens).
Number of doses: 1 or 2 doses (two different trials)
Clinical trial identifier: NCT04614948 NCT04505722
Study location: 99 locations across the world
This vaccine from Janssen, a subsidiary of the pharmaceutical giant Johnson and Johnson (JNJ), utilizes JNJ has announced that it will begin phase III clinical trials prior to the completion of phase I/II trials. Preliminary results from its phase 1/2 trials showed excellent safety and effectiveness. We probably won’t know the interim phase 3 results until just prior to submission of the data to VRBPAC.
Novavax
Vaccine candidate name: NVX-CoV2373
Type of vaccine: This vaccine uses a stabilized form of the coronavirus spike protein which employs Novavax’s recombinant protein nanoparticle technology. The purified protein antigens in the vaccine cannot replicate and cannot cause COVID-19. The vaccine also contains a proprietary adjuvant, MatrixM™. Adjuvants are additives that enhance desired immune system responses to vaccines. The vaccine can be stored at above freezing temperatures.
Phase 3 status: The clinical trial is ongoing and will include up to 30,000 participants.
Number of doses: 2
Clinical trial identifier: NCT04611802
Study location: USA and Mexico
US-based Novavax has developed a genetically-engineered nanoparticle vaccine using a Matrix-M adjuvant. Novavax has extensive experience in developing these vaccines, although none have received FDA approval as of today.
There is no interim information about the clinical trial, but again, we should get some details after the scientists unblind the results in preparation for submission of data to VRBPAC.
Summary
With two vaccines already approved and two to three more in the COVID-19 vaccines pipeline, we might be able to fight the pandemic by the middle of 2021, if all of these vaccines have long-term effectiveness. Furthermore, there are well over 100 other COVID-19 vaccines further up the pipeline in preclinical and phase 1 clinical studies.
Of course, this doesn’t mean we are done with the pandemic. We still need to wear our facemasks and stay at home.
Notes
- As I’ve discussed before, every vaccine sold in the USA is produced in the USA, European Union, Japan, Canada, or Australia. No, this is not some sort of xenophobia, it is because there are strict standards for vaccine manufacturing – the US FDA, for example, inspects and reviews documents of every vaccine manufacturing facility on a regular basis. China, for example, has a history of manufacturing vaccines that are dangerous.
Citations
- Ewer K, Sebastian S, Spencer AJ, Gilbert S, Hill AVS, Lambe T. Chimpanzee adenoviral vectors as vaccines for outbreak pathogens. Hum Vaccin Immunother. 2017 Dec 2;13(12):3020-3032. doi: 10.1080/21645515.2017.1383575. Epub 2017 Oct 30. PMID: 29083948; PMCID: PMC5718829.
- Voysey M, Clemens SAC, Madhi SA, Weckx LY, Folegatti PM, Aley PK, Angus B, Baillie VL, Barnabas SL, Bhorat QE, Bibi S, Briner C, Cicconi P, Collins AM, Colin-Jones R, Cutland CL, Darton TC, Dheda K, Duncan CJA, Emary KRW, Ewer KJ, Fairlie L, Faust SN, Feng S, Ferreira DM, Finn A, Goodman AL, Green CM, Green CA, Heath PT, Hill C, Hill H, Hirsch I, Hodgson SHC, Izu A, Jackson S, Jenkin D, Joe CCD, Kerridge S, Koen A, Kwatra G, Lazarus R, Lawrie AM, Lelliott A, Libri V, Lillie PJ, Mallory R, Mendes AVA, Milan EP, Minassian AM, McGregor A, Morrison H, Mujadidi YF, Nana A, O’Reilly PJ, Padayachee SD, Pittella A, Plested E, Pollock KM, Ramasamy MN, Rhead S, Schwarzbold AV, Singh N, Smith A, Song R, Snape MD, Sprinz E, Sutherland RK, Tarrant R, Thomson EC, Török ME, Toshner M, Turner DPJ, Vekemans J, Villafana TL, Watson MEE, Williams CJ, Douglas AD, Hill AVS, Lambe T, Gilbert SC, Pollard AJ; Oxford COVID Vaccine Trial Group. Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK. Lancet. 2020 Dec 8:S0140-6736(20)32661-1. doi: 10.1016/S0140-6736(20)32661-1. Epub ahead of print. PMID: 33306989; PMCID: PMC7723445.
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