CATIE News

Updated October 30, 2009

Summary

A vaccine for the prevention of H1N1 (also called swine flu) is available and free in Canada. HIV-positive people, and other people with weakened immune systems, are a priority group to get the H1N1 vaccine as soon as possible. Talk to your doctor or nurse about where and when to get this vaccine.

For many people, infection with the H1N1 virus causes mild-to-moderate flu symptoms—mostly fever, cough, sore throat, stuffy or runny nose, muscle aches—that resolve in about a week. However, in a small proportion of people, infection with the H1N1 virus can cause serious complications that may require hospitalization. We are not yet certain about all the factors that are responsible for these serious complications. However, based upon the best available evidence, people with weakened immune systems, including people with HIV, are expected to be at increased risk for complications arising from H1N1 infection. Talk to your doctor or nurse about developing a plan for what to do if you get flu-like symptoms or if your symptoms become more severe.

In this updated CATIE News bulletin, we provide you with key information about H1N1, including tips on the prevention and treatment of H1N1 in adults with HIV.

Are people living with HIV at increased risk for complications from H1N1?

Like other influenza viruses, the H1N1 virus does not affect everyone in the same way. As H1N1 is an emerging infection, there is very little information about its specific impact on people living with HIV. Based on current understanding, here are some of the factors that may increase vulnerability to H1N1-related complications for people living with HIV.

People whose immune systems have been weakened by HIV are at increased risk for complications from influenza and possibly the H1N1 virus. This includes people with low CD4+ counts. Because many people are not diagnosed with HIV until the late stages of infection, there is a hidden population of people in this category who don’t know they are HIV positive and are at increased risk for complications arising from influenza and H1N1 infection.

HIV-positive people who have high CD4+ counts may also be at increased risk, even if they are taking anti-HIV drugs. Several studies have found that despite the use of anti-HIV drugs, people with HIV are still at increased risk for complications arising from seasonal flu, such as bacterial chest infections.

Some people with HIV can have other conditions that can weaken the immune system and may make them more vulnerable to complications of seasonal flu, including the following:

• diabetes;
• cardiovascular disease;
• asthma;
• kidney dysfunction;
• having received a transplanted organ;
• pregnancy.

The conditions listed above may also increase the risk for complications from H1N1 infection.

How is H1N1 spread?

This virus is transmitted in the same way seasonal flu is spread. When an infected person coughs or sneezes, they release a spray of tiny droplets of mucus containing flu viruses. If these droplets are inhaled by a person in close proximity, that person can also become infected. If the droplets land on hard surfaces such as counters, desks, door handles or doorknobs, they can be picked up by touch. Another person who touches these surfaces and then his or her nose, mouth or eyes can become infected. Flu viruses can also be spread by direct contact between people’s mouths, by kissing, or by sharing things like drinking glasses and toothbrushes. Flu viruses can survive on the skin, so shaking hands with an infected person can transmit these viruses. Note that flu viruses can survive outside the body on hard surfaces for up to 24 hours.

How can I protect myself from becoming infected with H1N1?

The best way to protect yourself from H1N1 is to follow the tips below and get the H1N1 vaccine as soon as possible.

1. General tips

Here are some measures to help protect you from H1N1. These measures have generally been recommended by the Public Health Agency of Canada (PHAC), the U.S. Centers for Disease Control and Prevention (CDC) and the European Centres for Disease Control:

• Wash your hands frequently and thoroughly with soap and warm water or use alcohol-based hand sanitizer. It is particularly important to wash your hands before eating and after returning home from public places.
• Consider keeping an alcohol-based hand sanitizer at your desk, in your purse/briefcase or backpack so that it is always handy.
• Cough or sneeze into your sleeve if no tissue is available.
• Avoid touching your eyes, nose and mouth. If you must do so, use a tissue. Dispose of the tissue after use.
• When possible, avoid contact with people who are ill with flu-like symptoms. If you are looking after a friend or family member who has H1N1, we provide some ways below to help reduce your risk of getting H1N1.
• Get the vaccine against both H1N1 and seasonal flu. Even though H1N1 will become a common virus, other seasonal flu viruses will likely still be present this winter. Seasonal flu infection can cause dangerous complications in HIV-positive people. Note that the seasonal flu vaccine will not protect you from getting H1N1 and the H1N1 vaccine will not protect you from getting seasonal flu. And it doesn’t matter if you get either vaccination first, or with other vaccines. You can even get both vaccines at the same time, one in each arm.
• Your immune system gets weaker when you are run down, so be sure to get a balance of sleep, rest and exercise. Reducing stress and eating a good diet are also helpful ways to stay healthy.
• Talk to your doctor or nurse about developing a plan for what to do if you get sick with flu-like symptoms.

2. H1N1 vaccine

Health Canada has approved a vaccine for the prevention of H1N1.  This vaccine, called Arepanrix, contains an inactivated or dead form of H1N1. It cannot cause swine flu. Clinical trials have found this vaccine to be safe and effective in HIV-negative people. While we don’t have any specific information on the use of this vaccine for HIV-positive people, it is expected, based on years of experience with other flu vaccines, that it will be as safe as it is in HIV-negative people. Federal, provincial, territorial and municipal health authorities will be creating a strategy for vaccination throughout Canada. Stay informed and aware of when the vaccine will become available in your region (see the Resource section at the end of this bulletin for information on how to stay informed). Talk to your doctor or nurse about where to get this vaccine.

Adjuvants

Adjuvants are compounds that enhance the immue system’s ability to respond to a vaccine. Arepanrix is available in two formulations, with an adjuvant, called an adjuvanated vaccine; or without an adjuvant, called an unadjuvanated vaccine). Adjuvants have been used for many years in vaccines for the prevention of other infections. In Canada, adjuvants have not previously been used with flu vaccines. The H1N1 vaccine contains very small amounts of two adjuvants: vitamin E and a naturally occurring oil called squalene. In addition, the vaccine contains a tiny amount of a dispersing agent called polysorbate 80. This latter compound is often used in ice cream to help break up fats. All three ingredients are safe.

Using an adjuvant means that less influenza proteins are needed in each vaccine and so more people can be vaccinated.

Preservative

Like many vaccines, Arepanrix contains a preservative—thiomersal, which contains a tiny amount of ethyl mercury. This is not the neurotoxic form of mercury (methyl mercury) that is found as a contaminant in the environment and food. Thiomersal has been used as a preservative in other vaccines for many years and has been found to be safe. The tiny amount of mercury in Arepanrix is not considered significant. Indeed, you will be exposed to more mercury if you eat a can of tuna.

Dosage and people

The Public Health Agency of Canada has issued these recommendations for Arepanrix dosing:

• Pregnant women—one dose of unadjuvanted (contains no adjuvant) vaccine. PHAC notes that in cases where the unadjuvanted vaccine is not available and “rates of H1N1 flu are high or increasing, women who are more than 20 weeks pregnant should be offered adjuvanted vaccine.”
• Aged 10 years or older—one dose of adjuvanted vaccine.
• Age 6 months to 9 years—2 half-doses of adjuvanted vaccine, given at least 21 days apart.
• Age less than 6 months—the vaccine should not be used

Which vaccine should I get first—H1N1 or seasonal flu?

It does not matter which vaccine you get first. They may even be given at the same time, in different arms or even with vaccines against other infections.

3. Prevention of H1N1 infection with antiviral drugs

Antiviral drugs such as oseltamivir or zanamivir can, in some circumstances, be used to help prevent H1N1 infection in people who are exposed to this virus but do not have symptoms of the flu. Using medicines in this way is called PEP—post-exposure prophylaxis. Most exposures—such as those with colleagues at work—are associated with very low risk of transmission and so PEP is not needed. But if you have been in prolonged, very close contact with a person who has been diagnosed with H1N1, speak to your doctor or nurse about whether antiviral drugs might help protect you from H1N1 infection.

What are the signs and symptoms of H1N1 infection?

Because the signs and symptoms of H1N1 infection are very similar to seasonal flu and other viral infections, only your doctor or nurse can help diagnose the cause of your symptoms. Here are some of the symptoms associated with H1N1 infection:

• fever;
• cough;
• runny or stuffy nose;
• headache;
• muscle or bone pain;
• chills;
• fatigue;
• sore throat.

In some cases diarrhea and vomiting may also occur.

In extreme cases, the following signs/symptoms may also develop. If you experience the symptoms below, immediately contact your healthcare provider or dial 911:

• difficulty breathing or shortness of breath;
• pain or pressure in the chest or abdomen;
• sudden dizziness;
• disorientation or confusion;
• severe or persistent vomiting.

What should I do if I have symptoms of H1N1 infection?

Because the signs and symptoms of H1N1 infection are very similar to seasonal flu and other viral infections, only your doctor or nurse can help diagnose the cause of your symptoms. If you experience flu-like symptoms, contact your doctor or nurse immediately for advice. They will help decide what steps should be taken, such as whether you need antiviral medicines.

To avoid infecting other people with H1N1, stay at home as directed by your doctor or nurse.

If you experience flu-like symptoms, do not assume that the cause is H1N1. There are many other serious infections and conditions that can cause similar symptoms. Always seek medical advice for managing severe symptoms.

How can I care for myself or someone else who has been infected with the H1N1 virus?

For many people with H1N1 infection, healthcare providers will recommend home care and careful monitoring of symptoms. For this reason, it is important to be prepared to take care of yourself and others at home.

1. General practices to prevent the spread of infection

• Everyone in the household should take the precautions outlined in the section above: “How can I protect myself from becoming infected with H1N1?”
• Washing your hands after touching the person who is ill, or the environment around them, or the items they have touched is very important. You may wish to have alcohol-based hand sanitizer in the house to help keep your hands clean. However, remember to keep hand sanitizer out of the reach of small children.
• Avoid sharing anything that may carry germs, such as towels, dishes or eating utensils. Keep the sick person’s towels, dishes and utensils separate from the rest of the household.
• Clean common surfaces and shared items frequently, such as door handles, tables, countertops, phones and remote controls.
• As much as possible, people infected with H1N1 should avoid close contact with others. This means keeping a distance of about two meters (or six feet), wearing a face mask or covering your mouth with a tissue. Consider having the person (or people) with H1N1 rest in a room by themselves, away from common areas of the home.
• People who have H1N1 infection should not have visitors until at least 24 hours after their fever has cleared. If fever-reducing medicines such as ibuprofen (Advil, Motrin) or acetaminophen (Tylenol) have been used, wait 24 hours after the time at which both the fever has ended and you have stopped taking anti-fever medication. Phone calls are safer than visiting.
• If your doctor or nurse agrees that you (or the sick person) can leave home for brief periods, wear a mask to avoid infecting others when you cough or sneeze.

2. Managing the symptoms of H1N1

Develop a plan with your doctor or nurse on how to manage H1N1 infection in your household. If your doctor or nurse has told you or someone in your household to stay at home because of H1N1 infection, here are some things to do to help manage illness and prevent the spread of infection:

• get plenty of rest;
• drink lots clear fluids such as water, juice, herbal teas or soup;
• avoid drinking alcohol, coffee, tea or energy-drinks, as they can dehydrate you;
• stay at home as directed by your doctor or nurse;
• if you have been prescribed antiviral drugs for the flu, take them exactly as directed;
• monitor symptoms closely and contact your doctor or nurse if they become more severe.

When your symptoms have cleared, talk to your doctor or nurse about returning to work or volunteer activities. In the days after your symptoms have cleared, your body will produce gradually decreasing amounts of H1N1. So once you are back at work or volunteering, it is important to keep washing your hands and practice safer coughing and sneezing behaviour so that you do not infect other people.

What treatments are available for H1N1?

There are two antiviral drugs available on prescription that can be used to treat H1N1:

• oseltamivir (Tamiflu)—available as tablets;
• zanamivir (Relenza)—available as an inhaled powder.

These are the only medicines approved by authorities for the treatment of H1N1. They are most effective if used within 48 hours of the appearance of flu symptoms. Because the symptoms of seasonal flu are very similar to symptoms of H1N1, only your doctor or nurse can help diagnose the cause of your symptoms. So if you think that you might have H1N1, talk to your doctor or nurse right away.

Usually treatment with these drugs lasts for five days. However, in cases of severe illness, particularly in people with weakened immune systems who have been hospitalized, some infectious disease specialists may prescribe longer courses or higher doses of treatment.

Here are some helpful tips to bear in mind when taking these antiviral drugs:

• Take anti-flu medicines exactly as prescribed by your doctor or nurse. If you do not take your medication on time every time or if you do not finish the entire prescription, H1N1 may be become resistant to the medication. If H1N1 develops resistance, the medication will no longer work for you. Furthermore, you risk spreading this treatment-resistant H1N1 to someone else.
• Do not share your anti-flu medicine. If you think that a friend or loved one has H1N1, tell them to contact a doctor or nurse for help. It is important to be certain that the person has H1N1 before taking the medications. Many other serious infections and conditions can have symptoms similar to H1N1.
• Remember that oseltamivir and zanamivir are the only approved anti-flu medicines. If your doctor prescribes them for you, get them from a pharmacy, not over the Internet. Drugs ordered over the Internet may not be safe.
• No natural health products (vitamins, herbs or supplements) have been proven to be effective in preventing or treating H1N1.

More information about the treatment of H1N1 can be found at this site: http://www.cdc.gov/H1N1flu/recommendations.htm

Safety of antiviral drugs

Oseltamivir and zanamivir are generally safe in men, and in women who are not pregnant. However, note that all drugs may be associated with side effects, including allergic reactions.

In pregnant women, oseltamivir and zanamivir have not been tested in large rigorous clinical trials. However, doctors have had to treat pregnant women with these drugs so there is some information about their safety. The best available data suggests that these drugs are safe during pregnancy and breast feeding. U.S. CDC has noted that pregnant women who have H1N1 can be given these drugs. Zanamivir tends to concentrate in the lungs while oseltamivir can reach all tissues in the body. The CDC therefore recommends the use of oseltamivir in pregnant women with H1N1.

• Common side effects—oseltamivir

Some people who used this drug reported such problems as nausea, vomiting and diarrhea. Taking oseltamivir with food may reduce nausea or vomiting.

• Common side effects—zanamivir

This drug may irritate the lungs of people who have pre-existing lung conditions, such as asthma. The U.S. CDC recommends that people with pre-existing lung conditions use oseltamivir instead of zanamivir.

For more information about less common side effects of oseltamivir or zanamivir, speak to your pharmacist.

Drug interactions

As H1N1 is an emerging infection, there is little information on interactions between anti-flu drugs and medicines used for the treatment of HIV infection. So far, no serious or life-threatening interactions between drugs used for the treatment of H1N1 and drugs used for the treatment of HIV have been documented.

Resources

As we learn more about the H1N1 pandemic, new information about the virus, the vaccines and the treatments will be released. Stay aware and informed by listening to or reading the news about H1N1 in your region. Additionally, as the winter outbreak of H1N1 unfolds, public health agencies will be posting updates.

The Public Health Agency of Canada has released the Your H1N1 Preparedness Guide, which you can download from www.phac-aspc.gc.ca/alert-alerte/h1n1/guide/pdf/h1n1_guide-eng.pdf, order through 1-800 O-Canada or Service Canada, or pick up at any Canada Post office.

Here are some other sites with reliable information:

Public Health Agency of Canada
CPHA's H1N1 Clearinghouse
Alberta Health and Wellness Ministry
British Columbia Centres for Disease Control
Manitoba Health Department
Ontario Ministry of Health and Long-term Care
Quebec Ministry of Health
Saskatchewan Health Ministry
U.S. Centers for Disease Control and Prevention
French Ministry of Health
European Centres for Disease Control
World Health Organization

Acknowledgement

We thank the following infectious disease specialists for expert review, helpful discussion and research assistance:

• Dr. Andrea Boggild – Mt. Sinai Hospital, Toronto
• Dr. Curtis Cooper – Ottawa Hospital Research Institute, Ottawa
• Dr Allison McGeer – Mt. Sinai Hospital, Toronto

—Sean R. Hosein

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