However, the intensity of the infection in those who have been vaccinated is lower, said doctors, noting that they have only mild symptoms and recover easily.

The vaccines helped in easy recovery and lesser hospitalisation, said doctors. Doctors at Rajiv Gandhi Government General Hospital, Government Kilpauk Medical College Hospital and Government Stanley Medical College Hospital said they were receiving reinfection cases every day.

According to them, reinfection is commonly seen among youngsters, mainly frontline workers including doctors, nurses and other healthcare workers and volunteers. Most of them do not become critical and have been cured successfully, they added.

“There are cases of vaccinated persons getting infected. But they are recovering more easily and the duration of hospitalisation is lesser,” said Dr P Vasanthamani, dean, Government Kilpauk Medical College Hospital. “The symptoms during the first and second infections are different. When I got infected first, I had severe fever and breathlessness, accompanied with chest pain that lasted for months. My oxygen level was very low and pulse rate was very high. I had to get admitted to the hospital; it took me more than a month to recover during the first time. During the second infection, I had fever and chills, and lost my sense of smell and taste. But it was easier to recover,” said S Madhuri, a 25-year-old dental college student. Dr Arvind Santhosh, a PG student at Madras Medical College and Hospital, said the hospital was seeing a large number of cases of reinfection among fellow doctors and nurses in his ward. Those who have not been vaccinated yet have stronger symptoms than previous infection, said.

“Though they are not critically ill, the severity of symptoms is higher than last year among those who are not vaccinated. Many were asymptomatic or had very mild symptoms previously. But they have fever, and loss of smell and taste when infected again,” said Dr Arvind.