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Immunogenicity, reactogenicity and #safety to assess #booster #vaccinations with #BNT162b2 or double-dose #mRNA-1273 in adults ≥75 years (EU-COVAT-1-AGED) – final report

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By G.M.

 


Highlights

• Randomized trial of 1st and 2nd mRNA SARS-CoV-2 booster vaccination in advanced age

• Higher anti-RBD IgG level and neutralizing capacity with full-dose mRNA-1273 than BNT162b2

• Decrease in viral neutralization capacity after 12 months against all 25 tested SARS-COV-2 variants

• Oldest population in a SARS-CoV-2 vaccination study (mean 81 yrs)


ABSTRACT

Background

To determine long-term immunogenicity and reactogenicity of different SARS-CoV-2 mRNA-vaccines in a population ≥75 years in a randomized trial.

Methods

Participants were randomised to receive either BNT162b2 30µg or double booster dose mRNA-1273, i.e.100µg, as 3rd and 4th vaccination (1st and 2nd booster). Primary endpoint was rate of 2-fold geometric mean titre (GMT) antibody increase 14 days after vaccination targeting the receptor binding domain (RBD) region of wild-type SARS-CoV-2. Secondary endpoints included neutralising capacity against wild-type and 25 variants at 14 days (D14) and 12 months (M12). Safety was assessed by monitoring adverse events (AEs) for seven days after vaccination.

Findings

Between Nov-2021 and Sep-2022, 322 participants received a SARS-CoV-2 vaccine as a 1st (Part A) or 2nd booster (Part B). Primary endpoint results have been published previously. In Part A, it was reached by 100% in both vaccine arms with a higher GMT increase in the mRNA-1273 arm (ratio 1.64). At M12, GMT of anti-RBD IgG was slightly higher than at D14 (9,319.7 vs. 8,568.4IU/mL) in the BNT162b2 arm while in the mRNA-1273 arm, GMT was equal (14,163.8 vs.14,266.7IU/mL at D14.)

In Part B, primary endpoint was reached by 78.5% subjects in the BNT162b2 and 87.2% in the mRNA-1273 arm (p=0.056), respectively, with a higher GMT increase of anti-RBD IgG for mRNA-1273 (ratio 1.38). At M12, GMT of anti-RBD IgG was markedly lower than at D14 (9,962 vs. 15,248.2IU/mL) in the BNT162b2 arm as well as in the mRNA-1273 arm (12,024.3 vs. 21,325.6IU/mL). Higher neutralising capacity in individuals boostered with mRNA-1273 was detected against wild-type and 15/25 tested variants.

Less participants in mRNA-1273 arm had vaccine-related AEs (29.6% vs. 38.5%), but severity was more frequently grade 2 (n=38, 28.1 % vs. 22, 16.3%).

Interpretation

Long-term serological immunogenicity and virus neutralization capacity in subjects ≥75 years was numerically better with a mRNA-1273 100µg booster with comparable safety profile.

Source: 


Link: https://www.ijidonline.com/article/S1201-9712(26)00101-3/fulltext

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