Two doses of the COVID-19 vaccination has provided more protection against the virus and hospitalisation even to healthcare workers, who are prone to a high risk of infection, said a study by Christian Medical College, Vellore. However, the study did not study the impact of infections caused by beta (B.1.1.7) and delta (B.1.617.2) variants that led to the second wave. The study was posted on a preprint server, and is yet to be peer-reviewed. “The protective effect of vaccination in preventing infection, hospitalisation, need for oxygen and ICU admission were 65%, 77%, 92% and 94% respectively,” it said.
According to the study, out of 7,080 staff who were fully vaccinated, 679 contracted the infection, 64 were hospitalised, four needed oxygen therapy and two needed ICU care.
According to the study, 438 non-vaccinated medical staff tested positive for the virus and 11 needed oxygen therapy and ICU care. However, among the healthcare workers who took one vaccine shot, 200 tested positive for the virus but no one needed oxygen or ICU care. The hospital reported one death of a healthcare worker with comorbidities who was not vaccinated.
Among the workers who took both shots, thirty-three healthcare workers contracted the infection within two weeks of taking the second vaccine shot but did not require ICU care or oxygen. The study said, "Our study corroborates these studies that vaccination is protective, although we did not look at the variants responsible for the massive second wave."
The study was based on the infections reported among healthcare workers between February 21 and May 19, 2021. The study said, Christian Medical College, Vellore, a 2600-bed tertiary care hospital with 10,600 employees has vaccinated 8,991 staff between January 21 and April 30, 2021. Around 93.4% of the healthcare professionals in CMC received Covishield and the rest took Covaxin.
Seventeen percent of healthcare workers could not take the second vaccine dose since there was a vaccine shortage and this was later delayed due to the increase in the interval between doses announced by the Union government. The study said, "Beyond the immediate situation, implications for public health include cost-effective protection from infection, reduction of illness severity and an intervention to break the chain of transmission effectively."
"Even as many states choose to restrict movement to reduce stress on the healthcare system, we realise that future waves can at best be prevented or at worst mitigated through aggressive and widespread vaccination," it concluded.