of influenza A activity in 1968–1969, the CDC in June 1969 predicted little more than "sporadic cases" of influenza A in the 1969–1970 season. Influenza activity was indeed less than the preceding season, but there was "considerably more" than expected. The flu affected 48 states the following season but was widespread in only six, compared to 44 out of the 50 states in which activity was reported in 1968–1969. In October 1969, the CDC, alongside Emory University, collaborated with the WHO to host an international conference on the novel influenza in Atlanta. A wide range of topics was discussed, including the origin and path of the pandemic, the experiences of individual countries, and effective control measures, such as vaccination. Vaccine It became apparent once the extent of antigenic variation in the virus was recognized that a new vaccine would be needed to protect against it. However, production of the previously recommended vaccines in the US had concluded by July 1968, and supply of fertilized chicken eggs, in which flu vaccines are grown, was limited. The first cultures of the virus were provided to manufacturers in August by the Division of Biologics of the National Institutes of Health for preliminary study. A strain isolated in Japan was sent to the US and, after showing greater potential for vaccine production, was given to manufacturers on 9 September. In 1968, American microbiologist Maurice Hilleman was head of the virus and vaccination research programs at the pharmaceutical firm Merck & Co., one of the licensed vaccine manufacturers in the US. Hilleman, as the director of the Department of Respiratory Diseases at the Army Medical School (now the Walter Reed Army Institute of Research), had foreseen the 1957 pandemic and kickstarted vaccine production then. He was similarly instrumental in the development of the 1968 pandemic vaccine and, with the use of the Japanese strain, helped initiate early production. Merck would go on to produce over 9 million of the nearly 21 million doses of vaccine produced. The other half was produced together by Eli Lilly & Co., Lederle Laboratories, Parke Davis & Co., the National Drug Company, and Wyeth Laboratories. All of these except Wyeth had been involved in the production of the 1957 vaccine. On 15 November, 66 days after the production strain became available, the first batch of 110,000 doses of vaccine was released, most of which went to the Armed Forces. This