“People can have (COVID-19) antibodies, but it doesn’t mean they are going to be immune" to the disease, noted Galit Alter, a member of the Ragon Institute of MGH, MIT and Harvard, in a recent study that explored the immunity offered by antibodies against the coronavirus. Interestingly, the study was commissioned and co-authored by billionaire Elon Musk where he joined researchers to track coronavirus infection in 4,000 SpaceX workers who came forward as volunteers. The findings suggest that only a certain threshold of antibodies may provide people with lasting protection against the virus.
More than 4,000 SpaceX workers volunteered for monthly blood tests. According to the Wall Street Journal, who first reported about the study, the group published its findings this week. The study suggests that individuals who experienced fewer, milder Covid-19 symptoms generated fewer antibodies and were therefore, less likely to meet the threshold for longer-term immunity, the study found.
The immune decision to generate a robust or weak response may occur at the time of the host-pathogen interaction, dependent on the level of viral challenge, or inflammatory cues. "Low-level challenge may elicit only weak, poorly functional antibodies. Conversely, high-burden challenge may lead to the generation of a potent and functionally robust immune response, programmed to respond aggressively upon re-encounter with the pathogen," said the study appeared in the journal Nature Communications.
The results noted that unlike natural asymptomatic/mild infection, SARS-CoV-2 vaccines appear to drive robust immune responses.
"The good news is most of the vaccines induce (antibody) levels way higher than these levels," Alter said.
“To really nail this down at a public-health level would require doing reinfection studies and following people for reinfection" over time, said Joshua T. Schiffer, associate professor at the Fred Hutchinson Cancer Research Center’s vaccine and infectious-disease division.
The study was undertaken by Musk to monitor the prevalence of the virus among SpaceX workers nationwide. Musk and the rocket company’s top medical executive worked with doctors and academic researchers to build an antibody-testing programme.
The scientists who studied SpaceX workers say their findings could be used to inform who is most vulnerable to the virus and should be vaccinated first. For example, those with no antibodies in areas with high case counts could get priority, Alter said.
