By LEE BOWMAN
Scripps Howard News ServiceChildren with chronic respiratory problems and pregnant women are at the top of the government's priority list for vaccination against the new swine flu strain as it becomes available later this fall.
Federal health officials are still uncertain about delivery schedules or even the number of injections that may be needed out of the 160 million doses of novel H1N1 flu, but say there should be enough available by Thanksgiving to protect people at greatest risk of death or serious complications from the flu who wish to be vaccinated.
There are some 159 million Americans in the priority categories, who include, besides pregnant women, children 6 months to 4 years old, anyone up to age 64 with chronic medical problems that make flu symptoms worse, and health care providers.
There are, however, a substantial number of children and adults who, for various medical reasons, are not able to receive vaccination against either regular seasonal flu or the new swine flu strain.
Experts say extra care must be taken to protect them during any flu season, but particularly one where a new virus that seems to be readily shared, is the main bug in circulation.
First, there are the roughly 2 million babies under 6 months of age whose immune systems are not well enough developed to respond to a flu shot.
Dr. Tony Fiore, a medical officer with the federal Centers for Disease Control and Prevention's flu division, said parents should seek to create a "cocoon" of flu immunity around newborns and other children who can't get vaccinated. That means getting shots for everyone in close contact -- mom and dad, siblings, sitters and grandparents.
While there are some vaccines for childhood illnesses that pregnant women should not get, flu shots containing inactivated virus -- as the new vaccine does -- are not among them, doctors say.
Many, though not all, pregnant women who have come down with the new swine flu have become severely ill, and some have died. Pregnancy naturally suppresses a woman's immune system and can impair breathing as the baby grows to term.
"We've been vaccinating women for the flu for a long time and we've not seen any increased risk of birth defects or illness in the baby,'' said Dr. Anthony Fauci, head of the National Institute of Allergy, Immunology and Infectious Disease, during a government Webcast last week focused on protecting pregnant women from H1N1.
"If the H1N1 vaccine will also protect your newborn, there's no question that's the way to go,'' added. Dr. Laura Riley, an obstetrician-gynecologist at Massachusetts General Hospital in Boston.
Flu vaccination is also complicated for the 2 percent or 3 percent of children -- and the less than 1 percent of adults -- who are allergic to eggs. Virus for the vaccine is cultivated inside fertilized chicken eggs, and the serum may contain varying levels of egg protein.
Allergists say while some people with egg allergies can have life-threatening reactions to being vaccinated, many are able to safely get flu shots. The key is to have an allergist test for sensitivity to the specific vaccine, because researchers have shown the amount of egg in the serum can vary from season to season and even among manufacturers.
"If there seems to be a very strong reaction, you have to take it on a case by case basis, but most egg-allergic individuals can get flu vaccine with appropriate management,'' said Dr. Wesley Burks, chief of pediatric allergy and immunology at Duke University Medical Center in Durham, N.C.
Studies presented last year during the American Academy of Allergy, Asthma and Immunology's annual meeting found that children in two different trials who showed strong reaction to a skin prick test of flu vaccine were able to get immunized in 3 or 4 smaller, escalating doses with only mild reactions, if any.
The idea behind such divided, or incremental, doses is that the gradual exposure helps the patient become desensitized and able to tolerate the vaccine. Such a strategy could be particularly important with the new swine flu shot, which may require 2 doses to get to maximum immune boost possible.
"We haven't seen the vaccine yet, but it appears that if someone was able to get a flu shot in the past, they should be able to get it again. I really haven't heard concerns expressed from more than a couple of parents about this over the summer,'' Burks said.
One possible solution for the egg sensitive is a new type of vaccine that's grown in cells rather than eggs. Swiss-based Novartis is making this type of vaccine against the swine flu, as well as an egg-based vaccine. But company and CDC officials said only the egg-based vaccine is being supplied to the U.S. government, which is handling distribution of all swine flu vaccines to state and local governments.
A flu shot may not be an option for someone with a very strong reaction to the vaccine, or who has experienced a severe reaction to a flu shot in the past, including developing Guillain-Barre syndrome.
Fauci said quasi isolation and particular care in keeping surroundings sanitary may help protect such patients, but added, "I would also be much more concerned that if such a high risk person is exposed to the flu, they get on anti-viral therapy as quickly as possible."
