(RxWiki News) A universal flu vaccine to protect against all strains of the flu doesn't exist yet. But a new one does appear to protect against four flu strains at once.
A recent study found the new vaccine to be effective in preventing the flu among grade school-aged children.
The vaccine is called a quadrivalent flu vaccine because it protects against four different strains of the seasonal influenza virus.
There are two main types of flu virus strains: A and B. Most flu vaccines are trivalent and protect against two A strains and one B strain.
The quadrivalent flu vaccine protects against two A strains and two B strains.
"Ask your doctor about the seasonal flu shot."
This study, led by Varsha K. Jain, MD, MPH, of GlaxoSmithKline Vaccines in King of Prussia, Penn., looked at the effectiveness of a quadrivalent flu vaccine in children.
The researchers split a group of children, aged 3 to 8, into two groups.
One group of 2,584 children received the quadrivalent vaccine, and the other group of 2,584 children received a hepatitis A vaccine to act as a comparison.
In the group of children who received the flu vaccine, 62 of them, or 2.4 percent, caught lab-confirmed influenza.
In the other group of children who did not receive the flu vaccine, 148 of the children, or 5.7 percent, caught lab-confirmed influenza.
Based on these numbers, the researchers determined the effectiveness of the vaccine to be 59 percent. That number means that the quadrivalent flu vaccine reduced children's chances of catching the flu by 59 percent.
The researchers also looked at how many children developed moderate-to-severe influenza.
In the group who received the flu vaccine, 16 children, or 0.6 percent, developed moderate-to-severe influenza.
In the group who received the hepatitis A vaccine instead of the flu vaccine, 61 children, or 2.4 percent, developed moderate-to-severe influenza.
These numbers represented a vaccine effectiveness of 74 percent. Therefore, vaccinated children were 74 percent less likely to develop moderate-to-severe flu than children who didn't receive the flu vaccine.
The researchers also found that the children vaccinated against the flu were 30 percent less likely to develop a fever above 102.2 degrees Fahrenheit and 20 percent less likely to develop a lower respiratory tract illness compared to those not vaccinated against the flu.
The researchers also determined that the quadrivalent flu vaccine produced an immune response to protect against all four strains of the flu that it was intended to address.
Serious adverse events, or possible side effects, occurred in 36 children in the flu vaccine group (1.4 percent) and 24 children in the hepatitis A vaccine group (0.9 percent).
However, only one of the serious adverse events occurring in the flu-vaccinated group was determined to be caused by the flu vaccine, and none in the hepatitis A vaccine were caused by the shot.
The researchers concluded that the quadrivalent flu vaccine was effective in preventing flu in children.
This study was published December 11 in the New England Journal of Medicine. The research was funded by GlaxoSmithKline Biologicals.
Seven authors are employees of GSK, and five of them hold stock options in the company.
Five other authors have received research funding, speaker fees or advisory board compensation for a range of pharmaceutical companies, including Sanofi Pasteur, Novartis, Pfizer, Merck Sharp & Dohme and GSK.
