PCVs have important indirect effects on reducing vaccine-type carriage and invasive pneumococcal disease. A 2+1 dosing schedule of PCVs provides both direct and indirect protection across populations by inducing sustained functional antibody responses after boosting. More evidence comparing the direct and indirect protective effects of 3+0 and 2+1 PCV schedules is forthcoming.

1. PCV in developing countries
Give 2+1
Adam Finn
@adamhfinn
Bristol Childrens Vaccine Centre
MRF 5th Nov 2019, London

2. Is this your ideal
perspective?

3. ..or do you prefer to take
the broader view?

4. PCVs have important
indirect effects

5. This is not new...
Lancet Infectious Diseases 2001

8. Salivary antibody
responses
Choo et al. JID 2000 182

9. Functional antibody
after priming wanes..

11. Functional antibody
after boosting persists..

13. More antibody..
Madhi & Nunes Hum Vaccin Immunother. 2016 Feb; 12(2): 314–325

14. VT carriage - Kenya
Hammitt et al Lancet Glob Health. 2014 Jul;2(7):e397-405

15. ..and, of course, it’s not
just about indirect
protection..

16. From 12 months post-dose 3, the odds of VT IPD by 24–36
months increased significantly for PCV7 (5.6, 95% CI, 1.2–
25.4) and PCV13 (5.9, 95% CI, 1.0–35.2).

17. So:
• 3+0 provides direct protection for a
limited period – as shown in 2 RCTs.
• For people with blinkers it’s a dead
cert to do that – and only that
• 2+1 provides both sustained direct
and indirect protection across the
population
• For people with a broader perspective
it’s the obvious choice
• More evidence on 2+1 is coming soon