The Vaccine Shortage

The flu is caused by two types of viruses, influenza A and influenza B, each of which has several different strains. Influenza A is both more common and severe than influenza B. The viruses mutate a bit between each flu season, and dominant strains vary from year-to-year. In turn, scientists have to adapt the flu vaccine yearly so that it targets those strains they expect to be most widespread.

Health officials also have to predict consumer demand for the vaccine in a given year. The production process involves a lot of guesswork. In years when the vaccine successfully matches the appropriate flu strains, a protection rate of 70%-90% can be expected.

Manufacturing errors, such as the 2004 contamination fiasco in Great Britain, can also affect production. In 2004, the US Centers for Disease Control and Prevention (CDC) was notified by Chiron Corporation that none of its influenza vaccine supply would be available to the US due to inability to assure freedom from contamination. As a result, about half of the anticipated 100 million doses were suddenly unobtainable. In a rush to beat the season’s peak, health officials scrambled to secure more vaccine. In the end, they obtained extra doses from competing vaccine manufacturers, resulting in a total of approximately 60 million available doses.

To make optimal use of this limited supply, the CDC developed guidelines for vaccine distribution, prioritizing people at high-risk for complications, such as bronchitis, pneumonia, and other, more serious infections. Other high-risk groups include:

• Children age six months to five years
• Children 5 years and over with certain risk factors
• Pregnant women
• People age 50 years and older
• People with certain chronic medical conditions
• People who live in nursing homes or long-term care facilities
• Household contacts of any of the above
• Household contacts and out-of-home caregivers of children younger than six months of age
• Healthcare workers

The CDC website has updates on vaccine supply.

Additional Defenses

So if you don’t belong to one of the CDC’s priority groups, and, indeed, you do not receive a flu shot , what else can you do to protect yourself from the flu? First, remember that only the injectable form of the flu vaccine has been in short supply. The nasal spray vaccine (no needles needed) has consistently been available, is effective, and can be used in healthy people aged 2-49 years (who are not pregnant).

The CDC recommends taking the following steps to keep yourself and others from getting sick:

• Avoid close contact with anyone who is sick
• Stay home when you are sick
• Cover your mouth and nose when coughing or sneezing
• Clean your hands often—the number one vehicle for spreading germs.
• Avoid touching your eyes, nose, or mouth—since it’s almost impossible to keep your hands clean at all times! 

It’s also a good idea—as always—to get enough sleep, eat nutritious meals, drink plenty of water, engage in regular exercise, and find ways to manage stress in your life. This will keep your immune system strong throughout the cold and flu season.

Besides the vaccine, antiviral medications have recently been used to both prevent and treat the flu. They are often used as a secondary preventive measure in high-risk individuals who have also been vaccinated. Antiviral drugs work by inhibiting the spread of the virus within the upper respiratory tract. Specifically, the following four prescription drugs are approved by the Food and Drug Administration and commercially available in the US:

• Amantadine (Symmetrel)—an oral medication for the prevention and treatment of influenza A
• Rimantadine (Flumadine)—an oral medication similar to Amantadine but with fewer side effects, also for the prevention and treatment of influenza A
• Oseltamivir (Tamiflu)—a newer, oral medication for the prevention and treatment of influenza A and B
• Zanamavir (Relenza)—a newer, inhaled drug, similar to Oseltamivir, for the treatment only of influenza A and B

As prevention, these drugs are about 70%-90% effective for most adults. But while they are about as effective as the vaccine, they need to be taken consistently throughout the flu season, which greatly increases their risks and expense compared to the vaccine. As treatment, they can reduce symptoms of the flu and shorten its duration by an average of 1-2 days or so—if taken within two days of becoming sick. (The sooner they are administered, the more effective they are.) They can also make you less contagious to others.

It is uncertain, however, whether antivirals can treat the most severe, life-threatening cases of flu in high-risk individuals. Furthermore, possible side effects range from nausea to anxiety, depending on the drug. Additionally, they are not necessarily recommended for all individuals or all age groups. Relenza, for example, is not recommended for people with asthma or chronic lung disease, or for children under age seven. Like any prescription drug, you’ll need to discuss your medical history with your doctor before deciding if an antiviral drug is right for you. All antivirals must be prescribed by a doctor and taken for five days.

Flu Control in the Future

While it is unlikely that another vaccine shortage will occur in the near future, it’s important to keep in mind that even when there’s enough to go around, no vaccine is foolproof. Developers are not always successful. For example, one recent flu vaccine apparently protected only about 38% of those with a high-risk condition and 52% of individuals without a high-risk condition.

One big advantage of antivirals over vaccines is that they can be effective against a number of strains of influenza. Some flu strains, however, can quickly become resistant to Amantadine and Rimantadine. Still, if an unpredicted strain of flu (one that was not targeted by the vaccine) struck, an abundant supply of antivirals would be essential to saving thousands of lives. And since many specialists speculate that the coming of another influenza season of pandemic proportions is only a matter of time, sustaining adequate supplies of antiviral drugs may be well-warranted.