Establishment of a new human pneumococcal standard reference serum, 007sp

Area of Science:

• Immunology
• Vaccinology
• Biotechnology

Background:

• Lot 89SF, the established pneumococcal reference standard since 1990, faced depletion, jeopardizing vaccine efficacy assessments.
• The existing standard was crucial for evaluating the seven-valent pneumococcal conjugate vaccine (PCV7) and for licensing new vaccines.

Purpose of the Study:

• To develop and validate a replacement reference standard for pneumococcal enzyme-linked immunosorbent assays (ELISAs).
• To ensure the continuity of pneumococcal vaccine evaluation and licensure processes.

Main Methods:

• 278 volunteers were immunized with Pneumovax II, and plasma was collected and pooled.
• The new serum lot (007sp) was characterized and immunologically bridged to the previous standard (89SF) across 13 pneumococcal serotypes.
• Five independent laboratories performed bridging studies using WHO reference ELISAs.

Main Results:

• The new 007sp serum lot was established as the pneumococcal reference standard, successfully bridging to 89SF for 13 key serotypes.
• Concentrations in 12 existing WHO calibration sera were reassigned using 007sp, showing excellent agreement with previous values.
• The 007sp preparation is available in sufficient quantities for at least 25 years.

Conclusions:

• The 007sp serum lot effectively replaces lot 89SF as the pneumococcal reference standard.
• This new standard ensures the ongoing evaluation of pneumococcal vaccines and supports the licensure of new conjugate vaccines.
• The long-term availability of 007sp secures the future of pneumococcal serology standardization.