Covid-19: 50 jabbed medicos in K’taka test positive; Covaxin efficacy up 65% against Delta
Virendra Pandit
New Delhi: In a fresh spurt in coronavirus infections, nearly 50 fully vaccinated MBBS students have tested Covid-19 positive at a medical college in Dharwad, Karnataka, even as Bharat Biotech has enhanced Covaxin’s efficacy against the Delta variant to 65.2 percent, the media reported on Thursday.
About 40 students of SDM Medical College, all vaccinated with two shots each, had shown no symptoms of Covid-19. They had attended a get-together party in college premises a few days ago, health officials said.
After Covid tests, they were quarantined in their hostel rooms and are being monitored. Dharwad District Health Officer Dr. Yashvanth Madanikar visited the hostel to review the situation. The college campus was sanitized and sealed down.
Meanwhile, Hyderabad-based Bharat Biotech International Ltd (BBIL) has updated the efficacy of its indigenously developed vaccine, Covaxin, to 65.2 percent against the highly transmissible Delta variant, according to a study conducted by The Lancet Infectious Diseases Journal, published on Tuesday.
An effectiveness result of 50 percent, achieved during the Covid-19 second wave of Delta variant in India, in a high-risk study population of physicians and healthcare workers, at All India Institute of Medical Sciences (AIIMS), New Delhi, gave insights into the efficacy and effectiveness of Covaxin, the company said.
“These results compare well with the 65.2 percent efficacy against the Delta variant obtained during the controlled phase III clinical trials of Covaxin conducted among the general population. This study also shows that Covaxin meets the WHO efficacy criteria for Covid-19 vaccines for the dreaded Delta variant,” it said.
The results of an interim study, published in The Lancet Infectious Diseases Journal, showed that two doses of Covaxin, also known as BBV152, had 77.8 percent efficacy against the symptomatic disease.
Jacob John, former head of the Centre for Advanced Research in Virology at the Indian Council of Medical Research (ICMR) said the difference between the headline efficacy number and the real-world analysis on hospital employees, was because Bharat Biotech’s phase-3 trial was done on the general population, while the AIIMS study was conducted on healthcare workers and hospital employees who remained highly exposed to the virus, especially during deadly second wave in March-May 2021.
“The vaccine efficacy against severe disease, hospitalization, ICU admissions, or death is almost 100 percent. The 50 percent efficacy is against the symptomatic Covid-19 pandemic. No vaccine can protect against a breakthrough infection. However, it is important to watch whether it protects against severe disease and hospitalizations.”
According to him, vaccines are more effective after the vaccinated person gets a booster shot as well. The two-dose regimens are only the initial doses, and one needs a booster dose also for fuller protection.
