BENGALURU: In the wake of five
doctors in Chamarajanagar district testing positive for the SARS-CoV2 virus barely 12 days after they received the first dose of a
Covid-19 vaccine, experts have moved to calm fears, insisting that it is “impossible” for the vaccine to have been the cause of the infection.
The five from Chamarajanagar Institute of Medical Sciences decided to take the Covid-19 test after developing mild symptoms of the disease. Much to their chagrin, they found themselves infected. But experts say it could not have been because of the vaccine.
“The doctors probably were exposed to Covid-19 patients or asymptomatic carriers,” said a member of the state’s Covid-19 technical expert committee. “It’s also possible that the doctors were asymptomatic carriers when they took the vaccine. Had they shown any symptoms of the infection, they would not have been inoculated since the vaccine is given only to healthy individuals.”
Sources say two doctors, who had travelled from Mysuru to Chamarajanagar daily with the five infected doctors, also tested positive. These two were not vaccinated.
Experts say the two vaccines in use carry attenuated viruses — where the virulence of the pathogen is reduced so that it cannot cause any infection. Of the five, three had received Bharat Biotech-manufactured Covaxin, while the other two were given Covishield, Oxford-Astrazenca’s vaccine manufactured by Serum Institute of India, Pune.
Dr V Ravi, virologist and member, technical expert committee claimed the fact that all five were not given the same vaccine is ample proof that the infection was not triggered by the dose.
“Covaxin kills the virus and hence it does not cause infection,” Dr Ravi said. “Covishield carries a spike protein of SARS-CoV2 on adenovirus. Vaccines do not produce infection. If the doctors were exposed to the virus prior to vaccination and if the virus was in the incubation period when they took the vaccine, they would manifest the disease after the incubation is over. The doctors could have got the infection either at their workplace or through community spread.”
However, Dr Ravi says that it is erroneous to believe antibodies against SARS-CoV2 are developed immediately after taking the vaccine. “One must not think that s/he is protected the minute after taking the vaccine. It takes two weeks after the first dose to develop antibodies. On the 42nd day after the first shot, antibodies are seen,” said Dr Ravi.
However, incidents such as the one Chamarajanagar affect the inoculation drive with more people hesitating to receive the vaccine, another expert opined.
“Rajiv Gandhi University of Health Sciences will soon instruct healthcare professionals on the need to send out the right message on vaccine safety,” the expert said.
Dr MK Sudarshan, chairperson, Covid-19 technical advisory committee, clarified, “The vaccine prevents the disease, progression of the disease and death. It does not prevent infection in a person who is already exposed to the virus. The vaccine also does not stop transmission of the infection.”