The new year is also heralding in the prime time for seasonal flu cases as health officials brace for what is expected to be a particularly virulent season and encourage people to get vaccinated.
The Centers for Disease Control reported that influenza activity is increasing across the country and reports of flu illnesses, hospitalizations and deaths are elevated. Department of Public Health officials are reporting a rise in the number of cases in California, and are urging people do take precautions to help avoid catching the virus, including vaccination.
"California is experiencing an early influenza season this year, but it's not too late to vaccinate," said Dr. John Walker, the public health officer for the Stanislaus County Health Services Agency.
The CDC recommends that everyone six months and older receive a yearly flu vaccine. Each year's flu vaccine is designed to protect against the flu strains that research indicates will cause the most illness during the flu season. Traditional flu vaccines are made to protect against three flu viruses: an influenza A (H1N1) virus, an influenza A (H3N2) virus, and an influenza B virus.
Typically, the flu season peaks in February and March in Stanislaus County. The flu vaccine takes about two weeks to become effective.
This season the predominant flu strain appears to be seasonal influenza A H3N2 viruses, according to the CDC. In the past, this flu strain has caused more severe flu illnesses, hospitalizations, and deaths. For example, H3N2 viruses were predominant during the 2012-2013, 2007-2008, and 2003-2004 seasons, the three seasons with the highest mortality levels in the past decade.
Adding to the worries of a severe flu season striking the population is that health officials have been finding that approximately half of the H3N2 viruses analyzed are drift variants, meaning they are viruses with antigenic or genetic changes that make them different from that season's vaccine virus. This means the vaccine's ability to protect against those viruses may be reduced. During the 2007-2008 flu season, the predominant H3N2 virus was a drift variant yet the vaccine had an overall efficacy of 37 percent and 42 percent against H3N2 viruses, the CDC reported.
"While the vaccine's ability to protect against drifted H3N2 viruses this season may be reduced, we are still strongly recommending vaccination," said Joseph Bresee, M.D., chief of the Influenza Epidemiology and Prevention Branch at CDC. "Vaccination has been found to provide some protection against drifted viruses in past seasons. Also, vaccination will offer protection against other flu viruses that may become more common later in the season."
In addition to getting vaccinated, health officials recommend everyone help prevent the spread of the influenza virus by: washing their hands often with soap or water for at least 20 seconds or using an alcohol-based hand sanitizer; avoid touching their nose, eyes, and mouth; cover their mouth with a sleeve or tissue when they cough or sneeze; and if sick stay home for work or school.
For individuals considered the most vulnerable to complications from the influenza virus, such as those over 65 years of age, those with chronic medical conditions, and children under one year, immediate treatment is optimal.
"Antiviral treatment starting within 48 hours of onset is recommended for high risk groups," said Dr. Del Morris, the county's health agency medical director.