Dr. Kevin Most: Flu Shots
Last year was an incredibly difficult flu season, 80,000 Americans died last year from influenza. Just to put it in perspective this is 10,000 more than those who died from drug overdoses last year, and almost two times as many who died from car accidents. Close to 1 million individuals were hospitalized with influenza. Last year was the worst Flu season in over 40 years. If we look back over the past 20 years we see a range of 12,000 to 56,000 deaths. Last year was one of the most severe flu seasons that most of can remember. The key strain last year was one that was deadly to seniors and young children and hit the rest of the population quite hard as well. We had a season that started early, and did not peak until February and then slowly declined by the beginning of April.
Do we have any disadvantage living in a urban suburban area? One may think, No the flu season is the flu season. A recent study looked at flu cases for over 600 zip codes, it showed that flu cases in less populated areas lasted a shorter time and the surge was more intense when corrected for population. Larger cities saw a much longer duration of flu activity, which allowed exposure opportunities to continue. What that tells health officials is that smaller towns should be preparing for surge capacity where larger towns should be more concerned about limiting spread and exposure.
A few things made it a bad season. One was the strain that hit was one that impacted seniors and young children hard, The Type A H3N2 is and was a nasty virus. In seniors it will run rampant thru nursing homes an assisted living facilities where we have seniors together. It is one strain that often will end up in the lungs, most influenza viruses are content to hang out and wreak havoc in the upper respiratory system with few going on to pneumonia, H3N2 do not follow that pattern and are more able to get into the lungs. The second reason is that H3N2 viruses first showed up in the late 60’s, so that means that those over the age of 50 had the basis of their response to influenza actually set by other viruses. So those individuals in their 70s and 80s can fight off other influenza viruses better than they can H3N2. Individuals born after 1968 had early exposure to H3N2 and thus have an immune system that is able to respond to this virus better. And the final reason, we had a vaccine that just did not work or match up well, we discussed last year that the estimates for effectiveness were quoted anywhere from 25% to 60% with the true value settling at around a 40% effective rate. The bad thing was the ineffective part was against the strong H3N2 strain, the estimates for that portion of the vaccine had the effective rate below 20%. The message last year was even if you got vaccinated be careful and avoid the flu as much as possible.
So what are we doing this year? Well the vaccine has been updated to hopefully capture the H3N2 strain. All of the vaccines will be covering 4 strains, in the past we had 3 strain vaccines but over the past 5 years 4 strain vaccines have been tested and this year they will be used in all. Another big change is that the nasal spray flu vaccine will be allowed again in the US after a hiatus due to concern of effectiveness. The nasal spray is again only approved for those between the age of 2 and 49, and is not to be used in women who are pregnant. We will have high dose vaccine designed for those over the age of 65. This high dose vaccine is needed for seniors, as we age our immune response weakens so this higher dose vaccine attempts to make sure the body has a good immune response. Many studies have shown the response is better with the high dose vaccine. The vaccine has been shown to have the same safety profile as the regular dose vaccine so there is no reason for seniors to accept the regular vaccine.
So who needs a flu shot, essentially everyone over the age of 6 months. There is no vaccine for children under 6 months so special care must be given to infants that young to protect them from influenza. Many may think, that pregnant or those who have chronic illness should not get a flu shot and it is just the opposite, women who are pregnant should definitely receive the vaccine to protect themselves as well as their baby. It really comes down to the only individuals who should not get the vaccine are those with allergies to some component in the vaccine. Individuals with egg allergies should make sure the vaccine they receive is cell based and not egg based. No nasal spray vaccine for those under 2 yrs. old or over 50 yrs. old. Individuals who have compromised immune systems should discuss which vaccine is best for them.
Do we know how bad the flu will be this year? No but experts are concerned as we have already seen a death in North Carolina from influenza in a healthy middle aged woman. The concern is that many will take a pass and decide not to get vaccinated, as they feel last years shot was not helpful. This is the absolute wrong thing to do. We need to get higher vaccination rates. Remember even if the vaccine is not a perfect match you do get some protection and your immune system will make the episode lighter. The timing for the vaccine is now, get it before the end of October. It takes 2 weeks for the vaccine to be at full strength in your body, so getting it after you have had a direct exposure is not going to help. The goal is to be vaccinated well before we see the first outbreak. With the amount of travel we see at Thanksgiving everyone feels that having as many people vaccinated weeks before Thanksgiving is the best.