- Phase one of the trial of the trial is to check the safety of the vaccine
- Phase 2 of the trial is to check the efficacy and the dosage of the vaccine
- Phase 3 tests the safety and efficacy on a much larger sample
New Delhi: As we near the tenth month of the COVID-19 pandemic, all hopes hinge on vaccines that can help us stall the virus. COVID-19 vaccine candidates across the globe are getting tested for their safety and efficacy. There are some candidates that have reached the final stages of clinical trials, while most remain in the preclinical phase. The recent pause in the clinical trials of AstraZeneca and Oxford University’s vaccine candidate showed the importance of these rigorous trials. Dr Jyotsana Kumar, Senior Researcher explains to NDTV the three stages of clinical trials before a vaccine is approved.
Dr Kumar says that in the first stage of a clinical trial, the candidate is tested on small group of healthy adult volunteers, generally, 6-10 people. She said,
In this phase, safety of the candidate is tested and minor side-effects like headache and fever is expected. However, the vaccine is not considered safe if it triggers any critical or serious complications and if it does, it is considered unsafe and does not proceeded to the next stage.
When it comes to the second phase, Dr Kumar explains that this is conducted on a few hundred healthy adult participants to test the vaccine’s efficacy. She added,
The main objective of this stage is to see whether the vaccine triggers an immune response in the human body. In this phase, the vaccine dosage required to trigger an adequate immune response is also assessed.
In the third and the final phase, the vaccine is tried on thousands of healthy volunteers. For the leading COVID-19 vaccines, there are between 20,000 to 60,000 participants enrolled, Dr Kumar said. She added,
In this phase, the volunteers are divided into two groups, wherein one group gets the vaccine while the other one gets a dummy. The participants are not aware if they have got the vaccine shot or the dummy shot. These volunteers are allowed to carry on with their normal life. This is followed for several months to check on their responses. And every few weeks, they are checked to see if the group that got the vaccine, shows higher resistance to the infection than the group who didn’t get the vaccine. If yes, then the vaccine is considered effective.
When asked about the time duration for each phase of the clinical trials, Dr Kumar said that time frame usually that depends upon each disease, their vaccine technique and the demand. She explained,
When the disease is as serious as COVID-19 which has created a pandemic and the demand for the vaccine is extremely high, the entire process of vaccine development, their trials have been fast-tracked. In a usual vaccine development process, these phases are conducted over a span of several months and even years in some cases. Usually, a vaccine takes anywhere between 5-10 years to develop. 18 months for a COVID-19 vaccine is an extremely fast-tracked process due to the urgency of the health crisis.
Lastly, Dr Kumar said that the vaccine may be available in the mid-2021 as per her estimation. She further says that despite the fast track, she is hopeful about the safety and the efficacy of the vaccine since very renowned and respected pharma companies and research institutes are involved in the process.
NDTV – Dettol Banega Swasth India campaign is an extension of the five-year-old Banega Swachh India initiative helmed by Campaign Ambassador Amitabh Bachchan. It aims to spread awareness about critical health issues facing the country. In wake of the current COVID-19 pandemic, the need for WASH (Water, Sanitation and Hygiene) is reaffirmed as handwashing is one of the ways to prevent Coronavirus infection and other diseases. The campaign highlights the importance of nutrition and healthcare for women and children to prevent maternal and child mortality, fight malnutrition, stunting, wasting, anaemia and disease prevention through vaccines. Importance of programmes like Public Distribution System (PDS), Mid-day Meal Scheme, POSHAN Abhiyan and the role of Aganwadis and ASHA workers are also covered. Only a Swachh or clean India where toilets are used and open defecation free (ODF) status achieved as part of the Swachh Bharat Abhiyan launched by Prime Minister Narendra Modi in 2014, can eradicate diseases like diahorrea and become a Swasth or healthy India. The campaign will continue to cover issues like air pollution, waste management, plastic ban, manual scavenging and sanitation workers and menstrual hygiene.