Scientists at La Jolla Institute for Immunology in California showed that infection with common cold coronaviruses can generate an immune response that resembles key pieces of the immune response generated by SARS-CoV-2 – the virus that causes COVID-19. This raises the possibility that previous infection with one of the milder coronaviruses could make COVID-19 less severe.
Scientists who have been monitoring immune responses to the virus are now starting to see encouraging signs of strong, lasting immunity, even in people who developed only mild symptoms of Covid-19, a flurry of new studies suggests.
The study by Arizona University has shown that high-quality antibodies are still being produced five to seven months after SARS-CoV-2 infection. Learn about how the immune response works.
Sweden’s top health authority says people who have had the novel coronavirus are likely to be immune for at least six months after being infected, whether they’ve developed antibodies or not.
While the world is transfixed by the high-stakes race to develop a COVID-19 vaccine, an equally crucial competition is heating up to produce targeted antibodies that could provide an instant immunity boost against the virus.
The coronavirus that causes COVID-19 has sickened more than 16.5 million people across six continents. It is raging in countries that never contained the virus. It is resurging in many of the ones that did. If there was ever a time when this coronavirus could be contained, it has probably passed. One outcome is now looking almost certain: This virus is never going away.
People who have recovered from Covid-19 may lose their immunity to the disease within months, according to research suggesting the virus could reinfect people year after year, like common colds. Blood tests revealed that while 60% of people marshalled a “potent” antibody response at the height of their battle with the virus, only 17% retained the same potency three months later.
In short, though antibodies have proved invaluable for tracking the spread of the pandemic, they might not have the leading role in immunity that we once thought. If we are going to acquire long-term protection, it looks increasingly like it might have to come from somewhere else.
For every person testing positive for antibodies, two were found to have specific T-cells which identify and destroy infected cells. This was seen even in people who had mild or symptomless cases of Covid-19. But it's not yet clear whether this just protects that individual, or if it might also stop them from passing on the infection to others.
“Wait. I can catch Covid twice?” my 50-year-old patient asked in disbelief. It was the beginning of July, and he had just tested positive for SARS-CoV-2, the virus that causes Covid-19, for a second time — three months after a previous infection. While there’s still much we don’t understand about immunity to this new illness, a small but growing number of cases like his suggest the answer is “yes.”