In new studies, scientists found that immunity against Sars-2 or Covid-19 lasted for a year at the least. They estimated that immunity against Covid-19 could last for decades at least in some people.
Leh, May 31,2021: At least two new studies have given hope that people infected with Sars-2 or vaccinated against Covid-19 may have lifelong immunity against the disease. This, however, does not guarantee protection from re-infection but offers hope that the human body can develop antibodies that can fight Covid-19 for long.
These studies published here and here are significant as cases of re-infection have left both scientists and the public worried and wondering whether immunity against the Sars-2 coronavirus is short-lived. The fear has been that repeated vaccination — annual or six-monthly vaccination — may be required to ensure consistent immunity against Sars-2 or Covid-19.
In these studies, scientists found that immunity against Sars-2 or Covid-19 lasted for a year at the least. They estimated that immunity against Covid-19 could last for decades at least in some people.
The basis of their reinforced hope is the finding that the bone marrow could be involved in antibody production to fight Sars-2. In both the studies, researchers looked for immunity cells present in the bone marrow.
These cells live in the bone marrow and produce antibodies whenever required. Researchers found that antibodies start declining in blood a few months after recovery from Covid-19. They continued to detect antibodies for Sars-2 for 11 months.
What came as relief is the bone marrow connection, and continued ability of the immune system in generating T-cells, which remember the original infection and are able to neutralise pathogens when they come back to attack.
The scientists found that the immune system retained a portion of Sars-2 and immunity cells continued to evolve and get trained to fight the coronavirus infection with time. This also offers hope that the involvement of the bone marrow in producing antibodies may result in the body being able to fight against different variants of Sars-2.
The studies place the Covid-19 survivors better placed to fight future Sars-2 infection compared to those who developed immunity only through vaccination. The best immunity response is expected in those infected naturally and vaccinated subsequently. They may not actually need a booster dose ever.