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Phase 3 trials are most crucial in determining the efficacy of the coronavirus vaccine and several vaccines across the globe have reached this phase.
COVID-19 vaccine trials are ongoing at a rapid speed in India as well the world considering the need for prevention in these challenging times.
Most of the vaccines in the world are in phase 2 and phase 3 trials giving the world hope for the possibility of a vaccine by early 2021.
Phase 3 trials are considered to be crucial as they involve a large number of volunteers from various age groups and categories.
Can a volunteer be disqualified from a vaccine trial?
While some of the states are finding it difficult to gather the volunteers, some of them are rejecting the participants.
Oxford and AstraZeneca’s Covishield, which is one of the most promising vaccines which has seen prominent results in phase 1 and phase 2 trials, is under phase 3 currently in India.
While the trials have seen positive results from the public, recent reports have suggested that at least 7 participants have been found ineligible for vaccine testing by the Serum Institute of India.
According to the report, these volunteers were disqualified citing medical reasons and they would be screened this week again.
All seven candidates who were selected on Monday were disqualified due to various medical reasons including some of the volunteers testing positive for the coronavirus.
Though the volunteers are given the option to quit the trials at any point of time, the authorities too have issued certain guidelines as to who can enroll for the trials.
What is the enrolment strategy?
Not just for COVID-19, but the vaccine trial process for any type of disease is a tedious process.
There are certain categories of people who cannot participate in the COVID-19 vaccine trials:
● Pregnant Women
The immunity of pregnant women is already compromised and the vaccine trials would expose them to certain side effects which would prove harmful to the baby too.
The reactions are, however, different in the non-pregnant women. The doses of the vaccine implemented could also prove to be higher for the pregnant women which would in turn lead to unwelcoming complications.
So, only the women who are not expecting are allowed to participate in the vaccine trials.
● Those who are already infected
A vaccine trial is generally done to test the presence of immunity after the vaccine is injected.
For someone who has already contracted COVID-19, there will be enough antibodies present which would make it difficult for the vaccine to generate accurate results.
So, the person who is not infected in recent times will only be selected for the trial.
● Those on medication or steroids
People who are on any kind of medication can alter the results of the vaccine trials. Hence, it is preferred that a person who is healthy and devoid of any medication used to be tested for the vaccine.
● People with underlying medical conditions
If a person already has an underlying condition like diabetes or asthma, their immunity is already compromised.
So, the vaccine may not deliver the best results or can even produce side effects to such people.
Even if the high risk candidates are selected they are constantly monitored by the authorities.
● Those who live far away
Though the person is healthy and fit for the vaccine shots, if he/she lives far away or another state, the vaccine would not be administered.
This is because those who receive the vaccine shots shall be periodically monitored to check if they are developing any side effects.
There will also be regular followups and checkups on the patients.
- By Gayatri Yellayi