about the author
Fatima Kamalia M.D.
is a board certified pediatrician affiliated with the Hospital for Sick Children and York Central Hospital, and is a partner at Thornhill Pediatrics.

Flu season has begun, and there are many questions that parents have about the flu shot for their child. This article is designed to give you answers and make sense of the best-practice guidelines when it comes the flu vaccine and your child.

It is generally advisable to get the flu shot as early as possible in the season, from early October to late February. The flu shot is recommended for infants starting from 6 months of age, right through to adolescence. It is a very safe vaccine and can help prevent serious illness among healthy children and teenagers. Children at the highest risk include those that are otherwise healthy between 6 and 23 months of age, or those with any of the following health conditions, such as cardiac or respiratory disease (asthma or cystic fibrosis), diabetes or immunocomprised conditions (cancer or medication-induced), liver or renal disease, and anemia or hemoglobinopathies (sickle cell or thalassemia). If your child has any underlying health condition, they are considered high risk for catching the flu virus, and developing complications such as dehydration, pneumonia, ear infections, or rarely death. Catching the flu can also increase the risk for developing a rare neurological disease known as Guillan-Barre syndrome (GBS).

The best way to protect a vulnerable child is to ensure that every member in your household, including other children, are properly vaccinated. This way you can build a circle of protection for the most vulnerable individuals in your family. Long-term studies in the United States and other parts of the world have even shown the benefits to babies if their mothers are vaccinated while pregnant. These mothers were less likely to give birth to premature or underweight babies compared to those that didn't get properly immunized. Protecting your newborn child begins by taking the right steps for immunization even before they're born.

The regular dosages and need for a booster dose varies depending on your child's age. To gently coax their young immune system so that it can effectively protect them from the flu, infants 6-11 months of age will receive two "half-doses" of the flu vaccine, about a month apart. If your toddler (12-35 months) has never had a flu shot before, they will also receive the vaccine as two "half-doses"; however, if they have had the flu shot in a prior year, they're ready to receive a single half-dose dose of the vaccine. Pre-school and young school-age children spend the most time interacting in close quarters with each other, and have the highest chance of encountering and sharing the flu. Generally, they are also still learning about the importance of hygiene behaviours that can reduce flu transmission, such as covering sneezes and hand-washing. To help their immune system develop a robust defense against the flu, children between 3 and 8 years of age will receive a single normal doses of the flu vaccine, unless this is the first year they're getting the flu shot; in that case, they'll need two normal doses about a month apart. Generally, older children will only require a single normal dose of the flu vaccine. However, even children over 9 years of age with any underlying chronic illness will need the protection of two doses of the vaccine.

Most parents are concerned about providing their children with the best protection, while ensuring that any risk of side effects or discomfort is minimal. This year's flu vaccine has the advantage of providing a wider immunity with less needles. The 2010-11 season vaccine has the benefit of protecting against strains of both influenza subtypes A and B, including the H1N1 virus. As there is no live virus in the flu shot, there is no risk of your child catching the flu by getting the vaccine. Side effects from the vaccine are uncommon, but if they do occur these are usually restricted to some local soreness at the injection site which usually resolves within one or two days. Some children may favour or shelter their arm during this period. Other far less common reactions include redness or swelling at the site, headache, loss of appetite, and muscle ache; however, in studies, these side effects were as common with control or "placebo" treated patients as they were with those given the flu vaccine. Even less frequent are reactions such as chills, nausea, vomiting, diarrhea or rashes; even more rarely, activation of GBS may occur, though less frequently than in cases of infection with the actual flu virus. In most cases, the safest choice is giving your child the flu vaccine.

A previous history of allergy to any component of the flu shot needs to be considered prior to immunization. Since the flu shot is prepared in eggs, until recently, children with egg allergies were generally advised to avoid it. However, this left allergic children, who also often had asthma, without adequate protection against the flu. Fortunately, there has been strong evidence from several American studies showing that even children with confirmed egg allergies can be safely given the flu shot. As of October 2010, the American Academy of Allergy, Asthma and Immunology has provided recommendations that egg-allergic children can get either a two-step graded challenge, or a single age-appropriate dose, after appropriate testing by an Allergist. This has provided reassurance and added protection for many parents and children against seasonal and pandemic strains of the flu virus.

It is a source of great reassurance to parents to know that the flu shot is strongly recommended for all children by all international pediatric associations, including the Canadian National Advisory Committee on Immunization (NACI), the World Health Organization (WHO), the Canadian Pediatric Society (CPS), the American Academy of Pediatrics (AAP), and the Hospital for Sick Children (HSC).

With flu season under way, make sure you book or come into the office for the walk-in flu shot clinic, and keep your family safe from Influenza this year.

  1. American Academy of Allergy, Asthma and Immunology, Oct. 2010
  2. Nichols et al. "Side Effects Associated With Influenza Vaccination in Healthy Working Adults." Arch Int Med. 1996. 156:1546.
  3. Zaman K, et al. "Effectiveness of Maternal Influenza Immunization in Mothers and Infants." N Engl J Med, Oct 9, 2008; 359:1555-1564
  4. Sivadon-Tardy V. et al. "Guillain-Barré syndrome and influenza virus infection". Clinical Infectious Diseases (The University of Chicago Press); Jan 1 2009. 48 (1): 48–56
  5. Omer SB, et al. "Impact of maternal immunization against influenza on prematurity and birth weight" IDSA 2009; Abstract 703.
  6. Canada Communicable Disease Report: Statement on Seasonal Inactivated Influenza Vaccine (TIV) for 2010-2011. NACI, Health Canada. 36(6), August 2010.
  7. Influenza Fact Sheet. Toronto Public Health, October 2008.
  8. Jefferson T, Rivetti A, Harnden A, Di Pietrantonj C, Demicheli V (2008). "Vaccines for preventing influenza in healthy children". Cochrane Database Syst Rev (2): CD004879. doi:10.1002/14651858.CD004879.pub3. PMID 18425905.
  9. US Centre for Disease Control. "Children, the Flu, and the Flu Vaccine" http://www.cdc.gov/flu/protect/children.htm
  10. Demicheli, V.; Di Pietrantonj, C.; Jefferson, T.; Rivetti, A.; Rivetti, D.; Rivetti, D. (2007). "Vaccines for preventing influenza in healthy adults". Cochrane database of systematic reviews (Online) (2): CD001269. doi:10.1002/14651858.CD001269.pub3. PMID 17443504.
  11. Global Alert and Response: Recommended viruses for influenza vaccines for use in the 2010-2011 northern hemisphere influenza season. World Health Organization, August 2010.