EDITORIAL ANALYSIS : The right way to counter a poor Covaxin safety study
Kartavya Desk Staff
Source: The Hindu
• Prelims: Current events of national importance, Government policies, Covaxin, vaccination, Covid-19, Disaster Management Act).
• Mains GS Paper II: Government policies and interventions for development in various sectors and issues arising out of their design and implementations etc
ARTICLE HIGHLIGHTS
• Indian Council of Medical Research (ICMR) criticized the poor design of the long-term safety study of Covaxin by researchers from the Banaras Hindu University.
• Bharat Biotech pointed out the major limitations in the Covaxin study
INSIGHTS ON THE ISSUE
Context
COVAXIN:
• It is India’s indigenous Covid-19 vaccine.
• It was developed by Bharat Biotech in collaboration with the Indian Council of Medical Research’s National Institute of Virology, Pune
• It is an inactivated vaccine which is developed by killing the live microorganisms that cause the disease.
• It destroys the ability of the pathogen to replicate, but keeps it intact so that the immune system can still recognise it and produce an immune response.
• It targets more than just the spike protein.
• It develops an immune response to the nucleocapsid protein.
Issues with BHU study;
• The study lacked a control arm and data on the background rates of observed adverse events making it impossible to ascertain whether the adverse events observed were indeed caused by or associated with Covaxin.
• making it impossible to ascertain whether the adverse events observed were indeed caused by or associated with Covaxin.
• The study was carried out over the telephone and relied solely on participants’ recall of adverse events 12 months after vaccination, thereby introducing recall bias.
Method of vaccine study?
• A control arm is extremely important while studying vaccine safety. Only such a study can provide meaningful and reliable information about the adverse effects of a vaccine.
• Only such a study can provide meaningful and reliable information about the adverse effects of a vaccine.
• Studying the safety of a vaccine in thousands of participants for periods lasting one to three years is vital.
• Clinical evaluation of every adverse event is also paramount to rule out causality.
• Randomly assigning the participants either to an intervention arm or a control group is important to eliminate bias.
• A phase-3 randomized, controlled trial involving a large number of participants is thus ideal for studying vaccine safety.
Bharat Biotech and the ICMR study:
• It carried out phase-3 clinical trial that was randomized, placebo-controlled and double-blind, involving nearly 25,800 participants.
• The trial began in November 2020 and the interim results were first posted as a preprint on July 2, 2021.
• The interim results were based on data when 130 cases were reported in the trial.
• The safety data that was captured was only up to 56 days following vaccination.
Issues:
• Bharat Biotech and ICMR are yet to publish any long-term safety data of the Covaxin phase-3 trial.
• The failure to publish the trial safety data becomes more glaring as according to the information posted by the company in the clinical trial registry website The duration of the phase-3 trial was only for one year. Both the ICMR and Bharat Biotech have been in possession of the phase-3 safety data They have failed to publish them even two and a half years after the trial came to an end.
• The duration of the phase-3 trial was only for one year.
• Both the ICMR and Bharat Biotech have been in possession of the phase-3 safety data
• They have failed to publish them even two and a half years after the trial came to an end.
• Bharat Biotech had published six papers on Covaxin after the phase-3 interim results were published.
• The drug regulator had granted emergency-use authorisation for Covaxin under “clinical trial mode”, and the recipients were to be followed up for safety. In the second week, the drug regulator removed the “clinical trial mode” tag.
• In the second week, the drug regulator removed the “clinical trial mode” tag.
• According to the Head of India’s Vaccine Administration committee: More than 19 lakh people were administered Covaxin and 311 cases of “side-effects” were reported as on the day the drug regulator removed the “clinical trial mode” condition. Despite being in possession of these instances of adverse effects, no details of the vaccine safety have been published.
• Despite being in possession of these instances of adverse effects, no details of the vaccine safety have been published.
Types of vaccines
*Inactivated vaccines:*
● Inactivated vaccines use the killed version of the germ that causes a disease.
● Vaccines of this type are created by inactivating a pathogen, typically using heat or chemicals such as formaldehyde or formalin.
● This destroys the pathogen’s ability to replicate, but keeps it “intact” so that the immune system can still recognize it. (“Inactivated” is generally used rather than “killed” to refer to viral vaccines of this type, as viruses are generally not considered to be alive.)
● They usually don’t provide immunity (protection) that’s as strong as live vaccines. So you may need several doses over time (booster shots) in order to get ongoing immunity against diseases.
● They are Used to protect: *Hepatitis A, Flu (shot only), Polio (shot only), Rabies.*
*Live-attenuated Vaccines:*
● Live vaccines use a weakened (or attenuated) form of the germ that causes a disease.
● Because these vaccines are so similar to the natural infection that they help prevent, they create a strong and long-lasting immune response.
● The limitation of this approach is that these vaccines usually cannot be given to people with weakened immune systems.
● Live vaccines are used against: *Measles, Mumps, Rubella (MMR combined vaccine), Rotavirus, Smallpox among others.*
*Messenger (m) RNA Vaccines:*
● mRNA vaccines make proteins in order to trigger an immune response.
● mRNA vaccines have several benefits compared to other types of vaccines, including shorter manufacturing times and, because they do not contain a live virus, no risk of causing disease in the person getting vaccinated.
● The vaccines are used to protect against: *Covid-19*.
*Subunit, Recombinant, Polysaccharide, and Conjugate Vaccines:*
● They use specific pieces of the germ – like its *protein, sugar, or capsid* (a casing around the germ). They give a very strong immune response.
● They can also be used on people with weakened immune systems and long-term health problems.
● These vaccines are used to protect against: *Hib (Haemophilus influenzae type b) disease, Hepatitis B, HPV (Human papillomavirus), Pneumococcal disease among others.*
Toxoid Vaccines:
● They use a *toxin* (harmful product) made by the germ that causes a disease.
● They create immunity to the parts of the germ that cause a disease instead of the germ itself. That means the immune response is targeted to the toxin instead of the whole germ.
● Toxoid vaccines are used to protect against: *Diphtheria, Tetanus.*
*Viral Vector Vaccines:*
● Viral vector vaccines use a modified version of a different virus as a vector to deliver protection.
● Several different viruses have been used as vectors, including *influenza, vesicular stomatitis virus (VSV), measles virus, and adenovirus, which causes the common cold.*
● Adenovirus is one of the viral vectors used in some Covid-19 vaccines being studied in clinical trials.
● The vaccines are used to protect against *Covid-19*
Way Forward
• The long-term Covishield safety study has similar limitations as the Covaxin study. It found that people who received the vaccine after developing COVID-19 were two times at risk of persistent adverse events when compared to those who received the vaccine before COVID-19.
• It found that people who received the vaccine after developing COVID-19 were two times at risk of persistent adverse events when compared to those who received the vaccine before COVID-19.
• ICMR and Bharat Biotech owe it to the trial participants and the people who received the vaccine, and should publish the long-pending phase-3 vaccine safety data soon.
• It becomes essential for the state to balance between safeguarding the life and health of its citizens’ and individual decisional autonomy.
QUESTION FOR PRACTICE
Besides being a moral imperative of the Welfare State, primary health structure is a necessary precondition for sustainable development.” Analyze.(UPSC 2021) (200 WORDS, 10 MARKS)