Determinants of de novo B cell responses to drifted epitopes in post-vaccination SARS-CoV-2 infections (preprint)

Vaccine-induced immunity may impact subsequent de novo responses to drifted epitopes in SARS-CoV-2 variants, but this has been difficult to quantify due to the challenges in recruiting unvaccinated control groups whose first exposure to SARS-CoV-2 is a primary infection. Through local, statewide, and national SARS-CoV-2 testing programs, we were able to recruit cohorts of individuals who had recovered from either primary or post-vaccination infections by either the Delta or Omicron BA.1 variants. Regardless of variant, we observed greater Spike-specific and neutralizing antibody responses in post-vaccination infections than in those who were infected without prior vaccination. Through analysis of variant-specific memory B cells as markers of de novo responses, we observed that Delta and Omicron BA.1 infections led to a marked shift in immunodominance in which some drifted epitopes elicited minimal responses, even in primary infections. Prior immunity through vaccination had a small negative impact on these de novo responses, but this did not correlate with cross-reactive memory B cells, arguing against competitive inhibition of naive B cells. We conclude that dampened de novo B cell responses against drifted epitopes are mostly a function of altered immunodominance hierarchies that are apparent even in primary infections, with a more modest contribution from pre-existing immunity, perhaps due to accelerated antigen clearance.

No evidence that analgesic use after COVID-19 vaccination negatively impacts antibody responses (preprint)

Vaccines against SARS-CoV-2, the virus that causes COVID-19, showed high efficacy against symptomatic illness caused by the ancestral strain. Yet recent variants such as Omicron and its sublineages substantially escape vaccine-induced neutralizing antibodies. In response, bivalent mRNA booster vaccines updated to better match the BA.4-5 lineages have been made available. Yet the reactogenicity of these vaccines might negatively impact willingness to receive the booster immunization. While serious side effects following vaccination are rare, mRNA vaccines frequently lead to mild adverse events such as injection site pain, lymphadenopathy, myalgia, and fever. Over-the-counter analgesics might mitigate some of these mild adverse events, but animal models of SARS-CoV-2 infection have shown that non-steroidal anti-inflammatory drugs (NSAIDs) substantially reduce antiviral antibody responses, which are the best correlates of protection against COVID-19. It remains unknown whether these same inhibitory effects are seen in humans after mRNA vaccination. We surveyed 6,010 individuals who received COVID-19 vaccines regarding analgesic use and correlated these results with Spike-specific antibody levels. We found no negative impact of analgesic use on antibody levels, and in fact observed slightly elevated concentrations of anti-Spike antibodies in individuals who used painkillers. Logistic regression analyses demonstrated a higher proportion of those experiencing fatigue and muscle aches between NSAID users and those not taking pain medication, suggesting that the elevated antibody levels were likely associated with inflammation and mild adverse events rather than analgesic use per se. Together, our results suggest no detriment to painkiller use to alleviate symptoms after vaccination against COVID-19.