For most people, the typical, regular-dose influenza (flu) vaccine is enough to protect against seasonal flu infections. But for those 65 and older, a stronger, high-dose vaccine may be recommended.
Like other flu vaccines, high-dose flu vaccines are created from the flu strains that experts expect to cause the most infections during the typical flu season. High-dose vaccines are given by injection. The main difference is that they contain a higher dosage than the normal flu vaccine.
Why is a high-dose flu vaccine needed?
Older adults generally have less robust immune systems than do those who are younger. Because of this, a normal-dose flu vaccine generally produces 50% to 75% fewer virus-hunting antibodies in older adults than it would in younger adults. This can lead to older adults being less protected against flu infection after a regular flu vaccine.
The high-dose flu vaccine is very powerful, containing four times as much flu virus antigen — the part of the vaccine that stimulates the immune system — as standard flu vaccines. It’s designed to give people who receive it a stronger immune response against the flu.
Studies indicate that older adults have higher antibody levels after receiving a high-dose flu vaccine. One study found almost 25% fewer cases of influenza in adults 65 and older who took the high-dose vaccine, compared with those who took the standard-dose vaccine. Studies continue to evaluate the outcomes of high-dose flu vaccines.
High-dose flu vaccines tend to more frequently cause side effects than do regular-dose flu vaccines. These side effects include headaches, injection site soreness, muscle issues and fatigue. Still, these side effects are milder than a case of flu and typically go away after a couple of days.
Older adults have the highest risk among any age group of developing complications — including death — from a flu infection. That’s why it’s important for older adults to get a flu vaccine each year. You can ask your health care provider about getting a high-dose flu vaccine — or ask at the location where you get your vaccination. If a high-dose vaccine isn’t available for some reason — or if your health care provider says it’s not recommended for you — don’t skip your vaccination altogether. The regular-dose flu vaccine will very likely provide you good protection from the flu, even if it‘s not quite as strong as the protection that might occur with a high-dose vaccine.