A new study published in the journal ‘Science‘ from the American Association for the Advancement of Science has indicated that Covid-19 immunity could last for years.
The new study contrasts earlier studies that suggested immunity from Covid would be short lived, putting many people at risk of reinfection. That is no surprise as immunity from other coronaviruses have been short.
However, the new study indicates reinfection should only be a problem for a very small percentage of people who’ve developed immunity—whether through an initial infection or by vaccination.
It is important to note that this particular coronavirus has only been active for over a year now. New studies and data will often contradict each other, given how little we know about this virus.
This study took blood samples from 187 men and women that were infected with Covid-19. Most of the participants were only mildly infected, but 7% of them were hospitalised.
Each person provided at least one blood sample between six days and eight months after their initial symptoms, and 43 of the samples were taken after six months.
Researchers investigated several immunological agents that work together to prevent reinfection; antibodies, B cells (which make antibodies) and T cells (which kills infected cells).
The researchers discovered that the antibodies decline after eight months, although the levels vary between people. However, the T cells only declined moderately and the B cells remained constant and in some cases, actually increased.
This means that despite the level of antibodies decreasing after a period of time, the components that can restart antibody production and coordinate an attack against the coronavirus stick around at pretty high levels. It is believed that this trend will also happen in people who have been vaccinated for Covid-19.
Immunity from other coronavirus isn’t great but it is important to look at immunity from people who have recovered from the SARS virus, which has been described as a “close cousin of the virus that causes Covid-19”.
A study published last August shows that T cells specific to SARS can remain in the blood stream for up to 17 years, which offers hope that immunity from Covid-19 can last for years.
The new study isn’t perfect as it would have been better to have collected multiple blood samples from all 187 participants, but it is good news nonetheless. As this particular coronavirus is still so young, scientists and researchers are learning more about it all the time.
New studies carried out in recent times also suggest that vitamin D can lower the odds of developing respiratory illnesses, like Covid-19. Vitamin D is critically important in helping the immune system to resist viral infection and to limit inflammation when infection does occur.
Minister for Health, Stephen Donnelly has said that everyone in Ireland should be vaccinated by the end of September.
In essence, if the rollout of the Covid-19 vaccine worldwide goes well and more people increase their uptake of vitamin D, the pandemic will become a thing of the past.