As ever the headline only tells part of the story.
RNA vaccines seem to produce very different antibody levels
https://arstechnica.com/science/2021/08/rna-vaccines-seem-to-produce-very-different-antibody-levels/
Here’s the related paper.
Comparison of SARS-CoV-2 Antibody Response Following Vaccination With BNT162b2 and mRNA-1273
The SARS-CoV-2 messenger RNA (mRNA) vaccines BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna) have each shown more than 90% efficacy in preventing COVID-19 illness
1,
2but, to our knowledge, humoral immune responses have not been compared directly.
Methods
Health care workers at a tertiary care center (Ziekenhuis Oost-Limburg, Belgium) who were scheduled for vaccination with 2 doses of either mRNA-1273 or BNT162b2 were invited to participate in this prospective cohort. Serologic testing was performed prior to vaccination as well as 6 to 10 weeks after the second dose (between April 27 and May 20, 2021). Total immunoglobulin levels to the receptor-binding domain of the SARS-CoV-2 spike protein were measured with an anti–SARS-CoV-2 S enzyme immunoassay (Elecsys, Roche Diagnostics International Ltd). After vaccination, antibodies against the SARS-CoV-2 nucleocapsid protein were determined. Previous infection was defined as anti-nucleocapsid positivity at any point, anti-spike positivity before vaccination, and/or a history of positive polymerase chain reaction results on nasopharyngeal swab.
Antibody levels were compared after the second dose of each vaccine for the entire cohort; for those previously infected vs uninfected; and by age group (<35, 35-55, and >55 years) among previously uninfected individuals, using the
ttest after log10 transformation. Correlation between age and log10-transformed antibody levels was assessed with Pearson correlation. To adjust for confounding, a multiple linear regression was fitted with inclusion of age, sex, previous infection, and time between vaccination and serologic testing. All tests were 2-sided with statistical significance set at α = .05. Analyses were performed using RStudio (version 1.2.1335). This study was approved by the local institutional review board; participants provided written informed consent.
Results
Of 2499 health care workers who received 2 doses of SARS-CoV-2 mRNA vaccines, 1647 participated in this study. A total of 688 were vaccinated with mRNA-1273 (mean age, 43.2 years; 76.7% women; 21.8% previously infected with SARS-CoV-2), and 959 with BNT162b2 (mean age, 44.7 years; 84.9% women; 13.2% previously infected).
Higher antibody titers were observed in participants vaccinated with 2 doses of mRNA-1273 compared with those vaccinated with BNT162b2 (geometric mean titer [GMT], 3836 U/mL [95% CI, 3586-4104] vs 1444 U/mL [95% CI, 1350-1544];
P < .001) (
Figure, A).
Previously infected participants had higher antibody titers (GMT, 9461 U/mL [95% CI, 8494-10 539]) compared with previously uninfected participants (GMT, 1613 U/mL [95% CI, 1539-1690]) (
P < .001). In both groups, those vaccinated with mRNA-1273 had higher antibody titers compared with those vaccinated with BNT162b2 (previously uninfected: GMT, 2881 U/mL [95% CI, 2721-3051] vs 1108 U/mL [95% CI, 1049-1170];
P < .001; previously infected: GMT, 10 708 U/mL [95% CI, 9311-12 315] vs 8174 U/mL [95% CI, 6923-9649];
P = .01). The difference in antibody levels according to previous infection was higher than the difference between the 2 mRNA vaccines (
Figure, B and
Table).
Antibody levels negatively correlated with age in previously uninfected participants (correlation coefficient, −0.22;
P < .001), being highest among those younger than 35 years. Across all age categories, previously uninfected participants vaccinated with mRNA-1273 had higher antibody titers compared with those vaccinated with BNT162b2 (
P < .001 for all comparisons;
Figure, C).
The type of mRNA vaccine remained independently associated with the log-transformed antibody titer in a multiple linear regression (
P < .001,
Table).
https://jamanetwork.com/journals/jama/fullarticle/2783797