Flu immunization targets fall short for health workers and pregnant women

By Dr. Ananya Mandal, MDAug 18 2011

According to a new survey despite recent improvements in influenza vaccination rates among U.S. health care personnel, their rates for the 2010-2011 flu season still fell short of national health objectives.

Similarly, although the record-high influenza vaccination levels among pregnant women during the 2009-2010 influenza season were sustained during the 2010-2011 season, vaccination levels in that group also remained well below the “Healthy People 2020” target of 80% coverage for pregnant women, Dr. Carolyn Bridges said on the survey results.

Influenza vaccination coverage among all health care personnel for the 2010-2011 season was 63.5%, representing an increase over the 61.9% reported for the previous year. But that rate still fell short of the Healthy People 2020 coverage goal of 90%, said Dr. Bridges of the National Center for Immunization and Respiratory Diseases.

This survey results came from an Internet-based survey of 1,931 health care personnel, which the Centers for Disease Control and Prevention and the Rand Corp. conducted in April 2011. Dr. Bridges said, “The vaccination rates were highest among physicians, health care personnel working in hospital settings, and those aged 60 years and older.” Among the 13% of survey respondents whose workplace required influenza vaccination, the coverage rate was 98%, compared with 58% among the remaining respondents whose employers had no such requirement, she said. In the absence of mandatory workplace immunization, offering the vaccine onsite at work, free of charge, and on more than 1 day were associated with an increased likelihood of influenza vaccination, Dr. Bridges stated.

Onsite vaccination in particular was a “key strategy,” she emphasized, noting that the coverage rate among respondents who had the onsite option was 66%, compared with 38.5% among those who did not.

With respect to influenza vaccine during pregnancy, the CDC and Rand estimated coverage for the 2010-11 season using data from an Internet panel survey, also conducted in April 2011, among 1,457 women who were pregnant any time between October 2010 and January 2011.

“In all, 49% of respondents reported receiving the vaccine, including 32% who received it during pregnancy and 17% who received it [before or after] pregnancy,” said Dr. Bridges. The rate is comparable to the 50% coverage rate reported for the previous influenza season, in response to the 2009 H1N1 influenza pandemic. And it was significantly higher than the consistently low rates of approximately 15% reported in prior seasons, she said.

Pregnant women whose providers offered them the influenza vaccination were approximately five times more likely to get vaccinated than were those whose providers did not, “which is consistent with other studies,” Dr. Bridges said. Despite the fact that the influenza vaccine given during pregnancy has been shown to decrease illness in mothers and decrease the risk of influenza and hospitalization in newborns younger than 6 months old who themselves are too young to get the vaccine, “4 out of 10 women reported not receiving an offer for vaccination from their providers,” she reported.

An assessment of pregnant women’s attitudes and beliefs about vaccination during pregnancy determined that their top two concerns were safety risks to the baby and the possibility of getting influenza from the vaccine, Dr. Bridges stated. “Women who were offered the vaccine by their providers were more likely to have a positive attitude about the vaccine and its safety”, she said.

Although the 2011-2012 influenza vaccine will include the same influenza strains as last year, that’s not an excuse to skip this year’s shot, according to the CDC’s Advisory Committee on Immunization Practices. The CDC officials said, the five companies that make flu vaccine for the U.S. market expect to provide 166 million doses of vaccine. That compares with 157 million doses distributed last year. In addition to Sanofi-Aventis, GlaxoSmithKline, Novartis, AstraZeneca unit MedImmune, and CSL make flu vaccine for the U.S. market.

Children aged 6 months to age 8 who are getting a flu shot for the first time will need two flu shots - given at least a month apart - to build up immunity, according to the CDC recommendations. But children in that age group who were vaccinated last year will need only one flu shot.

The findings of both studies are reported in this week’s Morbidity and Mortality Weekly Report.