The question of immunity in COVID-19 survivors remains a hot topic among scientists. A recent pre-print study reveals that some patients never developed detectable antibodies.
Many COVID-19 patients experience mild symptoms and recover quickly. Yet, a British pre-print study published on medRxiv on June 9, 2020, found that 2% to 8.5% of patients showed no antibodies. Researchers measured IgG levels in 177 PCR-confirmed patients over two months.
Antibody production correlates with symptom intensity. Those with severe infections, older age, obesity, or hypertension were more likely to produce antibodies. Asymptomatic cases showed the lowest response. The team suggests this links to the inflammatory response, possibly triggered by higher viral loads.
No antibodies doesn't mean no immunity. The study notes potential "T-cell mediated or other antigen-specific responses." A prior German study hinted at cross-immunity from common colds. Mild cases might involve mucosal immunity, with antibodies localized and undetectable systemically.
This contrasts a French study from Institut Pasteur and Strasbourg University Hospital (May 2020), reporting 98% antibody positivity. All cited studies are pre-prints on medRxiv awaiting peer review.
Uncertainties persist on ideal antibody levels and duration. This could complicate vaccine development, as vaccines may reduce severity rather than prevent infection entirely.
