By David Brown
Washington Post Staff Writer
Friday, October 2, 2009
In a reminder that the new strain of H1N1 influenza may not be as benign as originally thought, federal health officials reported Thursday that 100 pregnant women infected with the virus were hospitalized in intensive care units in the first four months of the outbreak, and 28 have died.
"What we are seeing is quite striking," said Anne Schuchat, a physician at the Centers for Disease Control and Prevention in Atlanta who is helping direct the government's response to the pandemic.
"The obstetric caregivers here, and the ones that we're speaking with [around the country], have rarely seen this kind of thing in practice," she said at a weekly briefing. The 28 deaths occurred between the emergence of the strain in late April and the end of August.
Until this outbreak, hospitals were not required to report to public health authorities deaths from influenza, except in children. As a consequence, the "expected" mortality of pregnant women who become ill with seasonal flu strains is not known.
However, pregnant women have been among the victims of the novel H1N1 swine flu strain since the first cases were found in April.
"Whether this is more common or people are just noticing it because we're attending to this H1N1 virus, it's difficult to say," Schuchat said. However, she added, anecdotal reports are that "doctors around the country . . . have never seen this kind of thing before."
Most previous influenza pandemics have also had what appeared to be unusually high death rates in pregnant women.
In one series of 1,350 Spanish flu cases in pregnant women in 1918, 27 percent were fatal. In the Asian flu outbreak of 1957, half the women of reproductive age in Minnesota who died of the infection were pregnant.
Pregnant women are among the five "initial target groups" that public health authorities say should be offered the pandemic H1N1 vaccine when it is available.
In the briefing, Schuchat said that 600,000 doses of the nasal-spray form of the vaccine will arrive in 25 states and cities by Tuesday. The shipments mark the start of the unprecedented effort to offer a pandemic flu shot to every American who wants one.
The orders accepted Wednesday came from about half the jurisdictions -- states, territories and some large cities with their own health departments -- empowered to distribute the vaccine.
"We know that more will be ordering tomorrow, and the next day," Schuchat said.
The nasal vaccine is a live influenza virus that has been genetically weakened so that it can't cause illness and replicates only in the cooler temperatures of the nose. It can be taken by people ages 2 to 49, but not by pregnant women or people with chronic illnesses such as asthma, diabetes and kidney failure.
About 7 million doses of nasal vaccine should be available by the end of next week. The first doses of injectable vaccine -- which is made from genetically altered virus -- will arrive soon thereafter.
Most states are expected to direct the early supply to health-care workers. Ultimately, the vaccine will be available through at least 90,000 clinics, hospitals, doctors' offices and stores.
Use of the H1N1 nasal vaccine may be complicated by the recommendation that it should be given at least four weeks apart from the seasonal flu nasal vaccine.
Those who have already gotten that vaccine would have to get the pandemic flu shot for protection against the novel H1N1 strain, unless they want to wait at least a month for the nasal spray.
The need for the interval doesn't involve safety, said Anthony Fiore, a CDC physician and epidemiologist. Instead, some virologists believe the two "live" vaccines could compete with each other for the immune system's attention, resulting in sub-optimal response to one of them.
At the moment, however, that problem is theoretical, as there have never been two nasal flu vaccines available in the same season.
"Given the urgency of getting vaccination done, we're looking at whether shorter intervals are feasible," Fiore said.
The CDC reported "widespread" flu activity in 26 states last week.