By Vivek Singh Chauhan

New Delhi, Mar 21 (IANS): As India once again witnesses a surge in Covid-19 caseloads, health experts on Sunday warned people, especially those who have recovered from the deadly disease, to be extra careful as it is still uncertain how long someone is protected from getting reinfected.

Various studies have shown people who survived a Covid-19 infection continue to produce protective antibodies against key parts of the virus from two months to almost a year. However, according to health experts, there is still uncertainty to suggest that people are immune to Covid-19 after the first infection.

"As per the current research evidence, there is uncertainty about the duration of protection acquired after natural infection," Harshal R. Salve, Associate Professor at Centre for Community Medicine, All India Institute of Medical Science (AIIMS), New Delhi told IANS.

According to the US Center for Disease Control (CDC), antibodies usually start developing within one to three weeks after infection. But the CDC does not have enough information yet to confirm how protected someone might be from being infected again if they have antibodies to fight the novel coronavirus.

The confirmed and suspected cases of reinfection with the virus have been reported, but remain rare, according to the CDC.

According to Shiba Kalyan Biswal, Consultant, Pulmonary and Sleep Medicine, Narayana Hospital, Gurugram, people who have survived Covid-19 are safe for six to eight months from getting reinfected.

"After Covid-19 infection immunity remains for nearly 6 to 8 months. As far as the antibodies are concerned it may depend upon person to person, but infected people potentially develop antibodies within around two weeks, and for the same reason, also a minimum of two weeks isolation is suggested for infected patients," Biswal informed.

Recently, a study published in The Lancet medical journal stated that most people who get infected with SARS-CoV-2 are protected from catching it again for at least six months, however, people aged 65 and above are more prone to getting reinfected.

The experts also emphasised that the production of antibodies may vary from person to person as it depends upon various factors such as age, overall health, etc.

"Antibodies are produced in days to weeks after infection with the virus. The number of antibodies depends upon the severity of the disease, age, health, nutritional status and immunosuppressive conditions or medications," said Vikas Maurya, HOD, Pulmonology, Fortis Hospital, Shalimar Bagh, New Delhi.

"But majority develop in the second week starting with Immunoglobulin M (IgM) and later on Immunoglobulin G (IgG) from the third week onward," Maurya told IANS.

The cases of Covid-19 are rising amid the vaccination drive. As of March 20, India recorded 40,953 infections in a single day, the highest so far since November, taking the total tally to 1,15,55,284 on Saturday.

A single-day spike of 41,810 new infections was recorded on November 28 last year. The country has been registering an increase in cases for more than 10 consecutive days.

According to the Health Ministry, Maharashtra, Punjab, Karnataka, Gujarat and Chhattisgarh are exhibiting a steep rise in daily numbers.

With the death of 188 people in the last 24 hours, the toll has reached 1,59,558 in India. The active caseload in the country has mounted to 2,88,394.

As the virus is relatively new, the current understanding of reinfection remains low.

However, experts believe that ongoing and further studies will provide more insight into how frequently reinfection occurs.

Their current emphasis is on getting vaccinated, taking precautions against the virus, including mask-wearing and social distancing.