WHO released a revised position paper on Pertussis vaccination in the Weekly Epidemiological Record, reaffirming “that high coverage of infants with 3 doses of quality pertussis vaccine remains the most important element of pertussis vaccination programmes.” WHO recommends a 3-dose primary series with the first dose administered at 6 weeks of age, and subsequent doses given 4-8 weeks apart, at 10-14 and 14-18 weeks of age. The last dose of the recommended primary series should be completed by the age of 6 months, with a booster dose, given at least 6 months after the last primary dose, recommended for children 1- 6 years of age, preferably during the second year of life. The position paper includes information on the relative merits, in terms of efficacy, safety and cost-effectiveness, of the whole-cell and acellular pertussis vaccines, and detailed information on the administration and schedules for pertussis vaccines.

http://www.who.int/wer/2010/wer8540.pdf