Amid cases of the coronavirus infection being reported post-vaccination from a few parts of the country, experts have said inoculation against COVID-19 ''does not produce a shield'' against the deadly virus, but helps reduce the severity of the infection and chances of death.
They have also said that ''no causal link has been established'' yet between vaccination and the complications suffered thereafter by a person through any clinical or epidemiological studies.
From Delhi to Chennai and even in tier-2 cities like Patna, cases of vaccination beneficiaries contracting the coronavirus infection have been reported in the last couple of months.
Thirty-seven doctors at the Sir Ganga Ram Hospital in Delhi have tested positive for COVID-19 since the latest surge in cases, five of whom were admitted for treatment, hospital sources said last week.
Many of them had taken both doses of the Covieshield vaccine, the sources said.
A 54-year-old sanitation worker in Delhi died from health complications on February 22.
''My father had received his first shot of Covieshield on February 17. That day, when he returned home, he started feeling uneasy and the very next day, he was running temperature, which lasted for two-three days,'' his son Dheeraj had said.
He had said his father continued to go to work despite the ''weakness post-vaccination'', collapsed while being on duty and died at a hospital later.
In Chennai, a vaccination beneficiary, who had got his first shot on March 15, tested positive for COVID-19 on March 29. He was hospitalised on March 30 and died on April 4, raising concerns among the family members on the efficacy of the vaccine.
While cases of minor adverse events following immunisation (AEFIs) have been reported in various parts of the country, in some cases, it has been major too, leading to hospitalisation.
The Centre, however, has maintained that both Covieshield and Covaxin are safe to take, and urged people not to get swayed by rumours.
Several experts have concurred that vaccination against COVID-19 ''does not produce a shield'' against the deadly virus, but helps reduce the severity of the infection and chances of death.
''We know of cases of the infection reported post-vaccination, even after taking two doses. But these cases are largely where the beneficiaries have had very mild symptoms. The vaccine at least reduces the severity of the infection and chances of mortality,'' Dr Avdhesh Bansal, a pulmonologist at the Apollo hospital here, said.
Also, the full efficacy of the vaccine comes in only after two doses, he added.
Dr Richa Sareen, consultant, a pulmonologist at the Fortis hospital here, echoed Bansal, saying, ''The anti-bodies fully kick in only after both the doses have been taken. So a person getting infected after the first dose is possible if exposed to a source of infection.'' A senior doctor at a Delhi government hospital, on the condition of anonymity, said ''the vaccine is not a full safety shield'', but wearing masks can complement the fight against the virus, which is mutating in multiple ways.
''Many people after getting vaccinated think that now they are immune to getting the infection. So they either do not wear a mask or wear it improperly. The virus first attacks the nasal passage and then the chest region. So if the mouth and the nostrils are exposed, chances are high that a person, after vaccination, may still get infected,'' he said.
Also, the individual immunity level and associated co-morbidities could be a factor when it comes to getting infected after the first or the second dose of the vaccine, the doctor said, adding, ''Our mask is our best vaccine now.'' While medical and pharmaceutical industry experts debate over the efficacy of vaccines, many doctors conjecture that as the coronavirus has been mutating, it will affect the efforts to detect the infection, develop vaccination and capability to develop herd immunity.
So far, a UK strain, Brazil and South African variants and a double mutant of the virus have been reported in Delhi.
Vaccination of healthcare workers began in India since the launch of the inoculation drive on January 16 and then it was opened in phases to the elderly and those in the 45-59 age group with co-morbidities, with the Centre eventually allowing all aged above 45 to be eligible for immunisation against COVID-19.
The post-vaccination infection has brought trauma to the family members of the patients, who were hoping to get some reprieve after getting the shots.
Former IT cell head of the BJP and ex-CEO of MyGov Arvind Gupta on Friday wrote on Twitter: ''#Vaccine being put to test in our family. All taken Dose2 1. Patient 1 – Infected +- 7 days. In hospital with mild-moderate symptoms 2. Patient 2 – Infected +- 9 days. At home with high fever & cough 3. Patient 3 – Infected +- 14 days. At home with ~100F fever @MoHFW_INDIA.'' Hyderabad-based doctor Lakshmi Lavanya Alapati replied to his tweet on the microblogging platform, saying, ''After both doses are administered, antibodies develop and severity of infection and chances of death are lowered. There is an 85% reduction in chances of hospitalisation after vaccination. But vaccines cannot prevent the virus to enter your body – the only mask can stop virus entry.''