Science

Covid-19 immunity can only last for 12 months: Study

Prashasti Awasthi Mumbai | Updated on September 22, 2020 Published on September 22, 2020

The authors used these samples to look for cases of reinfection of four seasonal coronaviruses – HCoV-NL63, HCoV-229E, HCoV-OC43, and HCoV-HKU1.

According to a new study published in the journal Nature, immune responses developed against the novel coronavirus may not last for more than 12 months at a time.

This comes as many countries have started reporting incidents of reinfection, including the US and China.

For the study, researchers used serum samples that had been collected in the 1980s to study HIV and its risk factors.

The authors used these samples to look for cases of reinfection of four seasonal coronaviruses – HCoV-NL63, HCoV-229E, HCoV-OC43, and HCoV-HKU1.

Respiratory tract infections

These types of seasonal coronaviruses cause respiratory tract infections but are “otherwise genetically and biologically dissimilar.”

Researchers explained in their study: “Given this large variation, we hypothesise that characteristics shared by these four seasonal coronaviruses, such as the duration of protective immunity, are representative of all human coronaviruses, including SARS-CoV-2. Therefore, the aim of this study was to investigate the duration of protection from seasonal coronavirus reinfections.”

Researchers examined 10 healthy adult males who did not report any serious illness that could impact their immunity.

Antibodies level

Researchers noted in their study that they measured increases in antibodies level against the nucleocapsid protein — a common coronavirus protein — for each seasonal coronavirus. If they found a surge in antibodies level, they considered it to be a ‘fresh’ infection.

The researchers found as many as 101 coronavirus infections, ranging from three to 17 per individual. The reinfection time varied from six to 105 months (eight years, nine months).

The authors added that “there was no statistically significant difference between the infection interval lengths of the individual viruses.”

Researchers also mentioned that in a few cases, the reinfections occurred as early as six months – twice with HCoV-229E and once with HCoV-OC43 – and nine months (once with HCoV-NL63).

“Our serological study is unique because it avoids the sampling bias of previous epidemiologic studies based on symptoms-based testing protocols,” researchers wrote in their paper.

Follow us on Telegram, Facebook, Twitter, Instagram, YouTube and Linkedin. You can also download our Android App or IOS App.

Published on September 22, 2020
This article is closed for comments.
Please Email the Editor