1. Johnson & Johnson Pharmaceutical Research and Development, Turnhoutseweg 30, 2340 Beerse, Belgium.
2. Johnson & Johnson Pharmaceutical Research & Development, Campus de Maigremont-BP615, 27106 Val de Reuil Cedex, France.
3. Johnson & Johnson Pharmaceutical Research & Development, 920 Route 202, P.O. Box 300, Raritan, NJ 08869, USA.
4. Johnson & Johnson Pharmaceutical Research & Development, 50–100 Holmers Farm Way, High Wycombe, Bucks HP12 4DP, UK.
5. Swedish Institute for Infectious Disease Control, SE-171 82 Solna, Sweden.