Monday, June 5, 2023

What Is A Phase 3 Vaccine Trial

Phase I Clinical Trials To Assess Safety Dosing And Immune Responses

What is a Phase 3 Clinical Trial for a Vaccine Candidate?

Phase I clinical trials are the first step in assessing vaccines in people. Typically involving one to several dozen healthy volunteers, phase I trials assess short-term safety and immune responses, often with different vaccine dosages. Only if a vaccine candidate is shown to be safe in phase I trials will it move to larger phase II trials.

Phase 1 trials can be completed in two to three months, allowing for two doses of a vaccine three to four weeks apart

2-3 Years

The Investigational New Drug Application

Before a clinical trial can be started, the research must be approved. An investigational new drug or IND application or request must be filed with the FDA when researchers want to study a drug in humans. The IND application must contain certain information, such as:

  • Results from studies so that the FDA can decide whether the treatment is safe for testing in people.
  • How the drug is made, who makes it, whats in it, how stable it is, and more.
  • Detailed outlines for the planned clinical studies, called study protocols, are reviewed to see if people might be exposed to needless risks.
  • Details about the clinical trial team to see if they have the knowledge and skill to run clinical trials.

The research sponsor must commit to getting informed consent from everyone on the clinical trial. They must also commit to having the study reviewed by an institutional review board and following all the rules required for studying investigational new drugs

Phase I Clinical Trials

Doctors do a phase I clinical trial to learn if a new drug, treatment, or treatment combination is safe for people. They may have already tested it in laboratory animals.

In a phase I clinical trial, doctors collect information on:

  • The dose or treatment

  • When you take it, and how often

  • Any side effects or problems

  • How the treatment affects you, such as how it affects the cancer or side effects

In a phase I clinical trial, you could be one of the first people to get the new drug or treatment.

Phase I clinical trials each last several months to a year. They usually have 10 to 30 volunteers. The treatment might help the cancer. Also, information from the clinical trial may help other people in the future.

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Children Aged 517 Months

Among children aged 517 months who received three doses of RTS,S administered at 1-month intervals, followed by a fourth dose 18 months later, the vaccine reduced malaria by 39%, equivalent to preventing nearly 4 in 10 malaria cases. In addition, the 4-dose vaccine schedule reduced severe malaria by 31.5% in this age group, with reductions also seen in malaria hospitalizations, all-cause hospitalizations and the need for blood transfusions. Among children aged 517 months who did not receive a fourth dose of the vaccine, the protective benefit against severe malaria was lost, highlighting the importance of the fourth dose of this vaccine to maximise its benefits.

Inactivated Or Attenuated Coronavirus Vaccines

BVXV: Cohort 2 of Pivotal Phase 3 Universal Influenza ...

Vaccines created from weakened coronaviruses or coronaviruses that have been killed with chemicals.


Efficacy:72.8%Along with their Beijing Institute vaccine, Sinopharm also tested an inactivated virus vaccine developed by the Wuhan Institute of Biological Products. The Phase 1/2 trial showed that the vaccine produced antibodies in volunteers, some of whom experienced fevers and other side effects. Sinopharm then launched a global Phase 3 trial of the Wuhan vaccine. In December, Peru briefly paused their trial to investigate neurological problems that one volunteer experienced, but determined that it had nothing to do with the vaccines. On Feb. 25, China announced the approval of the Wuhan vaccine for general use. In May, the vaccine researchers the results of the Phase 3 trial, demonstrating that the vaccine has an efficacy of 72.8 percent.Approved for use in:China.Limited use in: United Arab Emirates.Updated May 29

Suspended import

emergency use

emergency use

emergency use

PHASE 2On March 16, 2021, Irans Ministry of Defenceannounced another vaccine made of inactivated coronaviruses. Known as Fakhravac, the vaccine is named after Mohsen Fakhrizadeh, Irans top nuclear scientist who was killed in November. After the completion of a Phase 1 trial, Fakhravac entered a Phase 2 trial in June.Updated May 6

emergency use

Note: Vaccines will be added to the tracker when they reach Phase 1, and tracked until they succeed or fail.

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Phase 3 Clinical Trial Of Covid

As the race to develop a safe and effective vaccine to protect against COVID-19 continues, phase 3 trials of investigational vaccines are underway. In this Q& A, Dr. Gregory Poland, an infectious diseases expert and head of Mayo Clinic’s Vaccine Research Group, explains the meaning of phase 3, whos being tested and the hopeful outcomes.

Journalists: Sound bites with Dr. Gregory Poland are in the downloads at the end of the post. Please courtesy “Gregory Poland, M.D. / Vaccine Research Group / Mayo Clinic.”

Q. What is a phase 3 vaccine trial?

A. A Phase 3 trial is really the last phase in the development of a vaccine before it goes through licensure. It is designed to measure efficacy and safety. After licensure, then we do so-called phase 4studies, which are really just attempts, once you’re giving it now to hundreds of thousands of millions of people, to catch any side effects that you didn’t in phase 3.

The phase 3 trials occurring now are designed to determine efficacy and safety. Efficacy meaning does it protect you against infection.

The Moderna vaccine trial has started. This trial will enroll 30,000 adults around the U.S., 10,000 of whom will get a saltwater placebo and 20,000 of whom will get the vaccine. In the same way, the Oxford vaccine trial will enroll 30,000 participants across Europe, Brazil and other locations.

Q. What will this phase help determine?

Q. Who are the vaccines being tested on?

Optimization Of Dose Schedule And Boosters

The speed of vaccine development for SARS-CoV-2 has been unprecedented. However, the time that companies and investigators might have to explore dose optimization and schedule has been reduced by the urgency of development. Fractional dosing has already been used to extend the supply of yellow fever vaccine,, and, if lower doses of COVID-19 vaccines prove efficacious and safe, then, particularly when supplies are limited, fractional doses might allow more people to be vaccinated. AstraZeneca reported that a regimen of half dose followed at least 1 month later by a full dose of chimpanzee adenovirus-based COVID-19 vaccine resulted in higher efficacy than two full doses given at least 1 month apart. Sinovac found that, for their whole-inactivated virus vaccine, extending the COVID-19 vaccine dosing interval from 2 to 4 weeks might have improved neutralizing antibody titers. Although closer spacing of doses might be advantageous during an outbreak, optimizing the schedule for magnitude and durability of induced responses might potentially make future COVID-19 vaccine campaigns more practical because they allow national programs time to plan and execute more effectively,.

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Epidemiology And Burden Of Covid

A key question about the epidemiology of COVID-19 has important implications for LMICs. Numbers of infections and COVID-19-related deaths appear to be much lower in Africa than in other parts of the world. Or, as we learned during the early days of HIV, are we not seeing cases because of lack of testing and case and death ascertainment? Some data would suggest that this is the case. Kenya has reported 93,000 cases of COVID-19 however, a nationwide blood bank survey estimated that 5% of Kenyans had been infected, implying a number closer to 2.5 million. Similarly, the absence of death registry data creates challenges in determining number of infections. The South African Medical Research Council noted that weekly excess deaths are trending 60% higher than in 2019, suggesting that current COVID-attributable deaths might be greatly undercounted, and some estimates put the number of infections and deaths even higher,.

Phase 3 Clinical Trial Of Investigational Vaccine For Covid

Moderna’s Covid-19 vaccine enters Phase-3 trials| What phase-3 involves | Oneindia News

Multi-site trial to test candidate developed by Moderna and NIH.

People 18 years of age and older who are interested in participating in this trial can visit or and search identifier NCT04470427 for details. Please do not contact the NIAID media phone number or email to enroll in this trial.

A Phase 3 clinical trial designed to evaluate if an investigational vaccine can prevent symptomatic coronavirus disease 2019 in adults has begun. The vaccine, known as mRNA-1273, was co-developed by the Cambridge, Massachusetts-based biotechnology company Moderna, Inc., and the National Institute of Allergy and Infectious Diseases , part of the National Institutes of Health. The trial, which will be conducted at U.S. clinical research sites, is expected to enroll approximately 30,000 adult volunteers who do not have COVID-19.

Moderna is leading the trial as the regulatory sponsor and is providing the investigational vaccine for the trial. The Biomedical Advanced Research and Development Authority of the U.S. Department of Health and Human Services Office of the Assistant Secretary for Preparedness and Response and NIAID are providing funding support for the trial. The vaccine efficacy trial is the first to be implemented under Operation Warp Speed, a multi-agency collaboration led by HHS that aims to accelerate the development, manufacturing and distribution of medical countermeasures for COVID-19.

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Key Points Of Phase Ii Clinical Trials

  • A group of 25 to 100 patients with the same type of cancer get the new treatment in a phase II study. Theyre treated using the dose and method found to be the safest and most effective in phase I studies.
  • Usually in a phase II clinical trials, everyone gets the same dose. But some phase II studies randomly assign people to different treatment groups. These groups may get different doses or get the treatment in different ways to see which provides the best balance of safety and response.
  • Placebos are not used in phase II trials.
  • Phase II studies may be done at major cancer centers, community hospitals or even doctors offices.

Larger numbers of patients get the treatment in phase II trials, so less common side effects may be seen. If enough patients benefit from the treatment, and the side effects arent too bad, phase III clinical trials are begun.

The End Of The Beginning

It will be important for vaccination, initially, to be seen as one part of a comprehensive package of COVID-19 prevention, which will include masks, distancing, hygiene and preparedness of healthcare facilities for an unknown period. Will misinformation, vaccine hesitancy, politics, deception and division undermine efforts to vaccinate communities and lower the burden of COVID-19? Global acceptability of vaccines varies from a low of 55% in Russia to a high of 90% in China. The WHO has issued a report highlighting the importance of up-to-date scientific information as the context in which an enabling environment, positive social influences and motivation will be critical to achieve high vaccine uptake, but this critical and complex subject is best pursued separately. For vaccination campaigns to be successful, governments must anticipate these issues and build trust and consensus around the safety, efficacy and necessity of vaccination.

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Key Points Of Phase Iv Clinical Trials

  • Phase IV studies look at drugs that have already been approved by the FDA. The drugs are available for doctors to prescribe for patients, but phase IV studies might still be needed to answer important questions.
  • These studies may involve thousands of people.
  • This is often the safest type of clinical trial because the treatment has already been studied a lot and has likely been given tot many people. Phase IV studies look at safety over time.
  • These studies may also look at other aspects of the treatment, such as quality of life or cost effectiveness.

You can get the drugs used in a phase IV trial without being in a study. And the care you would get in a phase IV study is very much like the care you could expect if you were to get the treatment outside of a trial. But in phase IV studies youre helping researchers learn more about the treatment and doing a service to future patients.

Why Do We Need Clinical Trials

6,000 UK participants sought for Covid

Clinical trials show us what works in medicine and health care. They are the best way to learn what works in treating diseases like cancer. Clinical trials are designed to answer some important questions:

  • Does the new treatment work in people? If it does, doctors will also look at how well it works. Is it better than treatment now being used? If its not better, is it as good and cause fewer side effects? Or does it work in some people who arent helped by current treatments?
  • Is the new treatment safe? No treatment or procedure even one already in common use is without risk. But do the benefits of the new treatment outweigh the risks?
  • Is this treatment better than the standard treatment given for this disease? Clinical trials help show if a new drug or treatment, or a new treatment combination, works better than what is now used.

Answering these questions, while giving as few people as possible an unknown treatment, often requires several clinical trials in different phases. Each phase is designed to answer certain questions while keeping the people taking part as safe as possible. Results from these phases show if the new drug or treatment is reasonably safe and effective.

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A Global Phase Iii Clinical Trial Of Recombinant Covid

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Recruitment Status : Enrolling by invitationFirst Posted : May 27, 2021Last Update Posted : November 2, 2021
Condition or disease
Biological: Recombinant COVID-19 vaccine Other: Placebo control Phase 3
Layout table for study information

Study Type :
Primary Purpose: Prevention
Official Title: A Global Multicenter, Randomized, Double-blind, Placebo-controlled, Phase III Clinical Trial to Evaluate the Efficacy, Safety, and Immunogenicity of Recombinant COVID-19 Vaccine , for the Prevention of COVID-19 in Adults Aged 18 Years and Older
Actual Study Start Date :
  • Virologically confirmed positive) symptomatic COVID-19 cases first occurring, regardless of severity. Virologically confirmed symptomatic COVID-19 cases first occurring 28 days after completion of 3 doses vaccination, regardless of severity.
  • The incidence of serious adverse events. Serious adverse events from Day 0 through 6 months after completion of 3 doses vaccination.
  • Phase Iii Clinical Trial

    Phase III studies study the safety and efficacy of the intervention in large groups of trial participants over time. They answer the following questions

    • How do people who get the vaccine and people who do not get the vaccine compare?
    • Is the vaccine safe?
    • Is the vaccine effective?
    • What are the most common side effects?

    The regulators will then review the trial results and determine whether to approve the vaccine or not.

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    What Happens In Phase Ii

    Phase II of a clinical trial involves several hundred participants who are living with the condition that the new medication is meant to treat. Theyre usually given the same dose that was found to be safe in the previous phase.

    Investigators monitor participants for several months or years to see how effective the medication is and to gather more information about any side effects it might cause.

    While phase II involves more participants than earlier phases, its still not large enough to demonstrate the overall safety of a medication. However, the data collected during this phase helps investigators come up with methods for conducting phase III.

    The FDA estimates that about

    How Long Will The Trial Take To Complete

    AstraZeneca Starts Phase 3 Vaccine Trials

    Investigators anticipate that the trial will take approximately three months to enroll 30,000 volunteers. However, since the trial is testing a two-shot regimen with about one month in between shots, some participants may not receive their second shot until the end of November 2020. It is difficult to predict exactly how long it will take to generate enough data to determine the efficacy of the vaccine candidate since this is dependent on the actual incidence, distribution and control of SARS-CoV-2.

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    Phase Iv Clinical Trial

    Drug companies may decide to conduct Phase IV trials after a vaccine is released. The manufacturer can continue to test the vaccine for safety, efficacy, and other potential uses. In the case of COVID-19, it may be necessary given the variability in the widespread population taking the vaccine.

    Therefore, it is clear that each stage of the trial provides important information regarding whether the vaccine works in individuals, and whether there are side effects. Usually it takes 8 to 10 years to conduct a robust set of clinical trials before approving a vaccine. This does beg the question of how COVID-19 vaccine developers will combine the phases of the trials to deliver a vaccine to the population in record time. We will have to watch this space!

    For more information you can view a: Coronavirus Vaccine Tracker

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