WASHINGTON (Reuters) - Vaccine experts who advise the U.S. government are likely on Wednesday to put healthcare workers, pregnant women and patients with asthma and diabetes at the front of the line to get vaccinated against the new pandemic H1N1 influenza.
The Advisory Committee on Immunization Practices may also at its meeting examine ways to manage a complicated U.S. flu season, with people getting seasonal influenza immunizations alongside swine flu vaccines.
“I think at the end of the day we’ll have a firm idea who will be recommended to receive vaccine against novel H1N1,” Tom Skinner, a spokesman for the U.S. Centers for Disease Control and Prevention, said in a telephone interview.
“We might expect to see various sets of recommendations that take into account a certain number of doses being available at any give time during our flu season.”
H1N1 swine flu is now so widespread that the World Health Organization has stopped counting individual cases. Health experts are afraid it could worsen, especially when the Northern Hemisphere’s influenza season starts in the autumn.
The U.S. government has contracted for 195 million doses of H1N1 flu vaccine for a possible autumn vaccination campaign. Health and Human Services Secretary Kathleen Sebelius said earlier this month the government would foot the bill.
HHS has also contracted for 120 million doses of adjuvant, a compound to stretch the number of doses of vaccine needed, and the ACIP, which advises the CDC and HHS on vaccine policy, may discuss various options for using the adjuvants.
Five companies are making H1N1 vaccine for the U.S. market — AstraZeneca’s MedImmune unit, Australia’s CSL Ltd, GlaxoSmithKline Plc, Novartis AG and Sanofi-Aventis SA.
It is not clear how much vaccine is going to be available. Flu vaccines are made using an old-fashioned method — inoculating eggs with the virus, letting it grow, and then purifying and inactivating it to make the vaccine.
Some companies have reported this particular virus does not grow well in eggs, limiting the yield. MedImmune says it does not have this problem, but it has only 40 million of the sprayers used to deliver its live vaccine into the nose.
Most experts agree that people are likely to need two doses of H1N1 vaccine to get full immunity, because very few have been exposed to the virus. Some studies have suggested that people over 50 may have some limited immunity.
Other studies have shown the vaccinating schoolchildren may be a good way to try to control the spread of the virus. Seasonal flu usually hits the very old, the very young and people with chronic diseases the hardest.
H1N1 not only hits those with chronic diseases particularly hard but also, unusually, young adults and older schoolchildren. Schools are breeding grounds for respiratory disease in general, and students bring these infections home to others who may be vulnerable.
Vaccine makers and academic centers are racing to test H1N1 vaccines in volunteers and in various doses to see what is safe and what dose is likely to best protect people. Some European countries have also suggested they may start vaccination campaigns before full results are available from these trials.
Editing by Paul Simao