New Delhi, Sep 10 (IANS): The suspension of a potential vaccine by UK-based AstraZeneca has raised concerns among the scientific fraternity and some of them on Thursday reiterated against rushing into the key human trials as a bad vaccine will only multiply the suffering humanity is currently going through.

Nearly four decades and 32 million deaths later, the world is still waiting for an HIV vaccine. An effective vaccine for dengue fever, which infects as many as 400,000 people a year according to the World Health Organisation (WHO), has eluded scientists for decades.

A clinical trial for an HIV vaccine was discontinued early this year since the vaccine was not found to prevent infections of human immunodeficiency virus, the virus that causes AIDS.

According to health experts, researchers must not break defined guidelines and processes involved in developing a vaccine, as finding shortcuts may do more harm than good in the long run.

In India, the Serum Institute of India (SII) is the partner of the University of Oxford's Jenner Institute to conduct vaccine trials. SII is currently progressing with the second and third phase study of the vaccine candidate at 17 trial sites across the country.

Covishield is the vaccine candidate developed jointly by pharma giant AstraZeneca and the University of Oxford.

"Although the Serum Institute of India has said they have not faced issues yet. But it remains a cause for concern and until investigations are completed the trial should be paused here (in India) as well," Dr Jyoti Mutta, Senior Consultant, Microbiology, Sri Balaji Action Medical Institute, told IANS.

"AstraZeneca is vigilant and responsible enough to immediately notify and pause the trial. Yes vaccine trials normally take a few years to determine the safety and efficacy before they are released in the market. This experience only shows that we should not rush trials and all precautions need to be followed," Mutta cautioned.

The SII has said that it will follow the instructions and protocols of the Central Drugs Standard Control Organisation (CDSCO) after receiving a show-cause notice from the central drug control authority on Wednesday.

The statement by the Pune-based vaccine manufacturer came after the Drug Control General of India (DCGI), VG Somani, issued a show-cause notice to it asking for an explanation as to why the institute decided to go ahead with the clinical trial of Covid-19 vaccine when doubts about patient safety were yet unclear.

According to Dr Navin Kumar, HOD Lab Services, Consultant Clinical Microbiology and Infection Control (Laboratory Medicine), HCMCT Manipal Hospitals, New Delhi, the AstraZeneca trial halt should be a cause of concern and requires investigations.

"But it also shows that the research team is observing high conduct of safety and efficacy," Kumar told IANS.

Dr Rajesh Chawla, Senior Consultant of Respiratory Medicine at Indraprastha Apollo Hospital, added: Phase 3 trials are generally the ultimate arbiter of whether a vaccine is ready for primetime - even as the demand for a vaccine or an effective drug to prevent or control COVID-19 has only been rising.

"However, hold on the vaccine trial is a routine action that has to happen whenever there is a potentially unexplained illness in one of the trials, while it is being investigated," Chawla said.

The world is eagerly waiting for a vaccine to deal with the deadly Covid-19 virus.

"The destination still seems to be far away. The reason is that the vaccine needs to be safe and effective. The regulatory pathway for the vaccine to be available is, thus, meant to be slow, deliberate, reflective, data-rich, data-informed, and peer-reviewed," said Anil Handoo, MD, Senior Director Hospital Lab Services at the BLK Super Speciality Hospital.